wrote: This is a little off the topic but I have a 100 watt dry load from MFJ. I'm looking to modify a retired AT SMPS to drive my ham-radio. A 10:1 resistive voltage divider may be connected between the dummy load and the oscilloscope probe to reduce the RF voltage applied to the probe, as shown in Fig. By design, the filament will get quite hot. I concur with @Madmanguruman recommendation about higher power rating for resistors. Low inductance dummy load resistors are a must for bench testing amplifiers. What is the difference between a resistor and a heating element? C $30.95; Buy It Now +C $12.14 shipping; Only 1 left! Discussion in 'General Electronics Discussion' started by Ben W., Mar 2, 2017. Use this calculator to find out the ohm value and tolerance based on resistor color codes. Inside a dummy load is a resistor. I now have a very nice dummy load: It's a simple thing, really, but I thought others might get some inspiration and/or at least be interested in the sources for the bits and pieces I used. Modern power supplies are not designed to be ran open circuit. 1 Watching. Mouser used to sell Xicon 3W metal oxide resistors in small quantities. Another slightly better solution for adding resistance to the circuit is to buy a "load resistor," or a "dummy load". Using Resistor as Dummy Load Reply to Thread. 5% tolerance. How to Calculate for Load Resistors. To learn more, see our tips on writing great answers. This non-linearity is illustrated by this plot: For more discussion on light bulb resistance, see pp.21-25 here. Mine was an open circuit, which I detected from my analyzer... thank god I didn't put it directly to my radio. Use MathJax to format equations. This includes: harm to minors, violence or threats, harassment or privacy invasion, impersonation or misrepresentation, fraud or phishing. Thanks for contributing an answer to Electrical Engineering Stack Exchange! On Sun, Nov 1, 2020 at 1:11 AM Raj vu2zap <. Only 1 math question on test dealing with dB. A dump load is nothing more than a resistor (heating element) that is used for dumping electricity when it is not needed or to prevent your battery bank from being overcharged. Why do bullets slow down from air friction? To test whether the SMPS is alive, I plan to put a dummy 10ohm 10W load across one molex connector. At least the container would be closed and keep the oil from spilling out. 555 Astable Calculator; 555 Monostable Calculator; Reference. It's usually a good idea to derate power resistors by 50%, especially if they can be inadvertently touched. And until now I've always used just a bare wirewound resistor with some banana plugs as a test load. Since I'd like to illustrate with a picture, I'm writing this as an answer rather than comment. My main dummy load. Can I submerge it in mineral oil to help it handle it’s rated input for longer? Top sponsor listing. are correct. Typically you would place a load on either/both the +5 or +12 V supplies to ensure minimum load. The triangular waveform oscillates between 1.2 volts … Use ohms law to calculate how much current and power is dissipated through the resistor. Are you sure you wish to delete this message from the message archives of BITX20@groups.io? 100 Pieces (Min Order) Chengdu Guosheng Technology Co., Ltd. CN 1 YRS. On Saturday, October 31, 2020, 10:43:28 AM EDT, Jerry Gaffke via groups.io wrote: On Saturday, October 31, 2020, 11:31:38 AM EDT, Jerry Gaffke via groups.io wrote: On Saturday, October 31, 2020, 1:37:56 PM EDT, N8DAH wrote: Good info. sluckey. The dummy load would typically be on a supply that did not have the minimum current load applied. Then you will know how big a resistor to use (e.g. That should give me a relatively compact dummy load for that power level, though it will require power for the fan. A non-inductive, pulse withstanding resistor, typically of this price level its a carbon composition or a carbon pile with horrific temper coefficients, but still. Could you please explain to me in certain detail how this high-side circuit works please? I ordered far too many of the 1K/3W resistors for this project. I bought mine from Rich at communications-lab.com: You may want to write first, as he was moving his business to HI when we last spoke. A nice dummy load. You. Electrical Code - I know of nothing in the NEC that permits you to calculate the impact on the "box-fill" when you slip in a 10/10 ceramic resistor that is putting out 80'F - 90'F 24/7. The dummy load control circuit (discussed on the next page) creates a triangular waveform that is used to switch the load resistor on and off. Is it wise to keep some savings in a cash account to protect against a long term market crash? C $5.57. Great idea! Does Schoenberg or Glenn Gould have a point? Mar 2, 2017. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Does a great deal of music remain to be written in C major? From Ukraine ; UNU-5 75ohm 75R 5W Metal Film Resistor Non-inductive HF/UHF Active Load. We did a similar DL for the November 2018 QST article which also had a watt meter built in. Just enter 2 known values and the calculator will solve for the others. What We Won’t Cover Pages 4-3 thru 4-5. Here is a simple dummy load for a atx power supply. 1Pc RF termination microwave resistor dummy load RFP 250N50 250w 50ohm KRFSci. Philosophically what is the difference between stimulus checks and tax breaks? Reclassify raster values continuously instead of assigning them to specific groups. I built a second one for about 70 cents. Center with equal amount of text per line. 1/6. By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy. US $4.80-$5.60 / Piece. Asking for help, clarification, or responding to other answers. If I did it, I'm place the dummy load into the container of oil vertically and probably leave the top of the container open. Power resistors generally don't immediately fail when overloaded, but they'll get extremely hot and may fail after a few minutes / hours. Why do LEDs need resistors and lamps do not in a series circuit, Chosing a suitable switch mode power supply, How to calculate power supply for 100x loads @ 3V 700mA. Reading on the internet indicates the SMPS may burn itself out if powered up without a load. Thanks Franco « Last Edit: November 20, 2016, 04:58:32 pm by kagliostro » Logged The world is a nice place if there is health and there are friends. October 21st, 2007, 04:31 AM. Matt shares with us his build of a fantastic looking dummy speaker load box. These could be an alternative if the ones specified for this project are hard to find. The SWR plot now shows five SWR dips in the 1-30 MHz range, none in an amateur radio band. Allow bash script to be run as root, but not sudo. Subject of the new topic: A number of you have written me privately saying you're having trouble finding the 1K 3W resistors for the dummy load project (Nov., 2018. I apologize if this is a dumb question but here is my dilemma. Resistor color code calculator. Inductive loads (like a pump or television) aren’t usually the best idea for a dump load but they have been used successfully on occasion. A 20-25W resistor (or a series-parallel combination of 4 10W resistors) would be appropriate. I was wondering if an inductor could be used to create the dummy load and if so how to calculate the value of such a load. Also, if you know that you're always going to be using QRP power levels, you could cut back on the wattage and that should make them easier to find (and cheaper). C $7.96; Buy It Now +C $7.28 shipping; From Bulgaria; 1pcs 10w 75 Ohm dummy load RF ceramic resistor HF power 20W long 200W short time. The resistors should be non-inductive, and of adequate power rating. 2, R1 = 9.1kΩ and R2 = 1kΩ. Making statements based on opinion; back them up with references or personal experience. To test whether the SMPS is alive, I plan to put a dummy 10ohm 10W load across one molex connector. 32966376132 in the Ali search bar, it finds the item. Mar 2, 2017 #1. K4EAA offered a set of resistors that I used in a Lowes empty quart can and mineral oil that had a banana jack and a bridge that you could use with a multimeter and calculate the power out into the dummy load. If yes, should I get a higher rated load, say 20W (if such a power-rating is available)? https://www.aliexpress.com/item/32966376132.html?spm=a2g0o.productlist.0.0.1a9e5261YmP5gm&algo_pvid=d2007a98-6b86-4a1d-80ce-61348dbc4deb&algo_expid=d2007a98-6b86-4a1d-80ce-61348dbc4deb-9&btsid=0bb0622d16041657591331983eada4&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_-- David. Building the Dummy Load. A carbon resistor does not present Inductance, which is one thing you do not want in a dummy load. Just a short note to convey I finally got around to verification using a halogen car bulb rated at 110W (+: Thanks a tonne, all! Since in most supplies they use co-regulation for +5/+12 or +5/+3.3 you may only need a load on one of them. Ben W. 3 0. On Sunday, November 1, 2020, 12:33:53 AM EDT, Christopher Miller wrote: You need a pretty serious heat sink to dissipate 500W though! Write this down! I'm planning to try doing a 100W one with a leftover CPU cooler to get rid of the heat. I think this violates the Terms of Service. Why don't all dividend-yielding companies offer dividend reinvestment plans (DRIPs)? I still have three sets of components as described....$10 includes postage. 2: Schematic of 10:1 voltage divider. But that ignores the rest of the circuit and that calculator only works for a single component. Ohm's Law Calculator. What We Will Cover . 31171 A dummy load is a popular device in amateur radio, commonly used instead of an antenna when a transceiver is tested or adjusted. EDIT: It uses a number of non-inductive resistors in parallel to achieve 50 Ohms over a wide frequency range. The dummy speaker load box is reconfigurable to 2-ohm, 4-ohms, 6-ohm, 8-ohm, 16-ohm and 32-ohm loads. On Sunday, October 28, 2018, 7:38:35 AM EDT, Dennis Zabawa wrote: Here is a power resistor I used in another dummy load. Load Resistor Wholesale High Quality Resistance Wirewound Load Wire Wound Resistor. Here's a caveat to be aware of. Reading on the internet indicates the SMPS may burn itself out if powered up without a load. How to calculate RMS (root mean square) of an AC voltage RMS = .707 x Peak. You can use this dummy load to simulate the load on the power supply circuit under different load conditions, to monitor the temperature curve in relation to load. The folded dipole is now a closed rectangular loop. A the same time, the light bulb resistance. SWR plot of my Un-terminated Folded Dipole - with a 4:1 balun at the feedpoint . http://hamradiodesigns.com/index.php/content/, https://www.arrow.com/en/products/mos3ct631r102j/koa-speer-electronics, Resistors - 3 Watt 1% - Page 2 - Communications Lab, https://www.mouser.com/ProductDetail/605-RHXH1Q100R0F4, https://www.aliexpress.com/item/4000012339390.html, https://www.ebay.com/itm/RFP1109-RF-Termination-Microwave-Resistor-Dummy-Load-RFP-100W-50ohm/264810641408?hash=item3da7f1b800:g:4pgAAOSwPjNed5Mb, https://www.aliexpress.com/item/32966376132.html. I've enough of the passive components plus D1(BAV21) for four additional builds. \$ 12V \times 8A = 96W\$ so I guess it should be good for about 80-85W. a 50 ohm 10% resistor. 75 Ohm 200 Watt 20kV Non-Inductive Dummy Load Resistor Silver Plated + Clamps. I wanted to build one of the dummy load resistors (along with many other tools I think I will be needing and wanting) but wondered if anyone off the top of their head knew where/which to buy. Dummy Load Resistor Aluminum Housed High Power Dummy Load Resistor RX24 200W 100w 50w 20w 10w. This is coming up a lot.. and I'm explaining it a lot.. so rather than keep doing that I'm making this thread right now. A dummy load is a pure resistor of value 50 ohms which can replace your transmitting aerial and enable you to operate the transmitter for test purposes without radiating a signal. Peak-to-Peak Voltage to Peak Voltage. Don't make it more difficult than it is and enjoy the useful 'free' desk light. Are you sure you wish to repost this message? Fig. Peak Envelope Power. I've looked on Mouser's and DigiKey site but wanted to make sure I was getting the right part (being a nubee). I wondered the same thing IF I got the MFJ dry dummy load. Why would merpeople let people ride them? I have been using these for my dummy loads and they have been pretty darn surprising. Using that calculator, the 6 Watt resistor would have to be 32 Ohms, and the 50 Watt resistor would have to be 4 Ohms. 12V @ 10 or 20W is called a (halogen) light bulb. @Madmanguruman recommendation about higher power rating for resistors, Podcast Episode 299: It’s hard to get hacked worse than this. Mouser has 2,837 of the 1k 3W Xicon in stock, item number 283-1.0K-RC, Another path to take, if you already have a 50 ohm dummy load, is to use that instead. Seeing others experiment with µC's in projects is terrific! Looking for the title of a very old sci-fi short story where a human deters an alien invasion by answering questions truthfully, but cleverly. Why does the Indian PSLV rocket have tiny boosters? Consider 2 *pi * 15,000 * L 94,200 ohms per Henry . I could also just buy a cantenna at some point. I've made up four kits consisting of 20 1K/3W, 1 56k, 2 1k (don't have 2k in my box)  resistors, D1 and C1 (50V--ok for QRP, but if you want the 150W version you should replace with a 250-500V as specified). Could an extraterrestrial plant survive inside of a meteor as it enters a planet's atmosphere? From China; 500W 50Ohm DC-1000Mhz Stripline Resistor Hybrid Dummy load 17-0356 DICONEX. http://www.hamradio.com/detail.cfm?pid=H0-001066 It's too bad they don't show the insides. Might need to find a deeper can if the components are too long. Nope - as long as the resistor is small enough to sufficiently load the ATX supply, the exact value is irrelevant. 10.0 Pieces (Min Order) Anhui Power Electric Co., … Is exact resistance realy important in this application? Someone just wrote to me and said Arrow carries them: but they are saying a December delivery. The SMPS lay unused for nearly 10 years now. Precision Resistor Wirewound Resistor Resistor 3 Ceramic Resistor Wire Wound Resistor Ohmite Rheostat Resistor 0 Resistor 100 Variable Resistor Power Resistor Resistor 1 Ohms Ohmite Model Ohms Power Resistor Ohmite Little Devils Watt Resistor 10 Ohm Resistor Resistor 10 100 Ohm Resistor Resistor 2 Decade Resistor Dale Power Resistor Vintage Ohmite Vitreous Enamel Rheostat Resistor … This is a response @jippie to his comment to the O.P., which suggests using a light bulb instead of a resistor. site design / logo © 2020 Stack Exchange Inc; user contributions licensed under cc by-sa. Drop me a private email if interested. US $2.00-$35.00 / Piece. My main dummy load. A beginner question - feel free to shoot me down. Was: Previous Price C $6.06. In the example shown in Fig. two in series and then in parallel for 8R Load. Electrical Engineering Stack Exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. Generally the higher the wattage rating of the resistor the more power the dummy load can safely handle. I think this message isn't appropriate for our Group. Resistance Calculators . I understood it is just to test if it functions properly. Search Forums; Recent Posts ; Scroll to continue with content. How to calculate maximum power when value of load resistance is unknown? So the \$10 \Omega\$ resistor can handle \$ 1A \$ current. By putting the resistor pack in mineral oil, we were able to run 200W into it for 5 minutes without failure. ... in a Lowes empty quart can and mineral oil that had a banana jack and a bridge that you could use with a multimeter and calculate the power out into the dummy load. Why? Evidently, some eBay suppliers say they have them, but the order quickly becomes a back order. Well, no longer! The new topic will begin with this message. I've been building audio amplifiers for years. The wattage of the dummy load is based around the wattage rating of the resistor(s) used in the circuit. A load resistor essentially serves the same purpose as the incandescent bulb in the solution described above – it simulates an electrical load, drawing sufficient current to the dimmer switch. These could be an alternative if the ones specified for this project are hard to find. I don’t want to bury a hidden light and I don’t want a heat generating resistor in line as well. Does a Kohen have to give "Chalah" from his own dough? What's relevant is whether or not the resistor will cook. Peak Voltage to RMS. Adding a temporary load to a power supply. one with a higher wattage). It sounds simple enough, but there are two main problems. @jippie Of course, I don't know how tolerant to the resistance variation will the power supply be. This is a take-off on a Dummy load that I've built in many different forms over the years. Is there a fluctuation effect between heat, resistance and current? 4 ohms R, in series with 4 ohms Xl , = 5.7 ohms Z 12 V × 8 A = 96 W so I guess it should be good for about 80-85W But allways I've a 200W Dummy Load is that correct ? It only takes a minute to sign up. Or should I build a new load? By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Service. Next, I simply interconnected (shorted) the ends of the dipole wires. Dummy Load basics (resistor type): A basic dummy load is made up from a NON-INDUCTIVE resistor with a final value of 50-Ohms, so it matches up to 50-Ohm transmitters. What about "Terumah" from fields that his wife inherited from her family? C $2.51; Buy It Now; Free Shipping; Free Returns. Global Moderator; Level 5; Posts: 22699; Re: Dummy Load - Question « Reply #1 on: November 20, 2016, 07:10:58 am » Quote. RC integrator: why does it convert a triangular wave into a sine wave? Since all the power supplies are different it's hard to be precise but aim for at least 1A on the 5V and 500mA on the 12V. MathJax reference. Calculations in the O.P. I would like to wire a dummy load up to the circuit to smooth things out. How to calculate power draw per rail, to see if Power Supply can handle the load? Is there a G-test equivalent for continuous variables? Check before you order. Of course, without the dummy-load terminating resistor, SWR is definitely nowhere near flat. It is submerged in oil to allow somewhat extended operation during tuning or repair procedures. Dimensions: 6-1/2" L x 1-9/16" W x 3/4" H; Inner width of the screw holes: 5.4 mm; Inside edge to inside edge measurement between the two screw holes: ~144 mm. The dummy should have no inductance. The following are tools to calculate the ohm value and tolerance based on resistor color codes, the total resistance of a group of resistors in parallel or in series, and the resistance of a conductor based on size and conductivity. Contact Supplier. Power Measurement in dB. It could be a water heater or air heater or some other resistive load. How do politicians scrutinize bills that are thousands of pages long? A most popular dummy load is one called a "Cantenna" which uses a very large carbon resistor submerged in a gallon can of Transformer oil. Here is a power resistor I used in another dummy load. Also it is a static 12V supply. How to calculate suitable dummy load for a power-supply? But when you build one of those in the image, I suggest that you leave the leads long since they help dissipate the heat. Calculate Power, Current, Voltage or Resistance. \$ P = I^2 \times R = (1.2A)^2 \times 10\Omega = 14.4W\$, or about 44% overload. Otherwise, maybe you can unmount the components in the dummy load and use the can lid to remount the components. To demonstrate this, we will use a 7805 linear voltage regulator to step the 12V supply down to 5V, and draw an increasing load … Write these down! Volts … the SMPS is alive, I will post here from the message of!: //www.hamradio.com/detail.cfm? pid=H0-001066 it 's too bad they do n't all dividend-yielding companies offer dividend plans. Whether the SMPS is alive, I will post here 've built many. And power is dissipated through the resistor pack in mineral oil, we were able to run 200W into for! Discussion ' started by Ben W., Mar 2, 2017 the item between 1.2 …! 2, 2017 20W is called a ( halogen ) light bulb will up. ; user contributions licensed under cc by-sa a great deal of music remain to be by... Un-Terminated Folded dipole - with a 4:1 balun at the feedpoint color codes politicians. Or air heater or air heater or air heater or some other resistive.... Rail, to see if power supply can handle the load it for 5 minutes without failure a... And said Arrow carries them: but they are saying a December delivery same if! May be drawn from it n't make it more difficult than it is submerged in to! Radio band which is one thing you do not want in a cash account to protect against a long market! User contributions licensed under cc by-sa 4 ohm load maximum amperage may be from. See any reason why you ca n't but it might get messy current! Buy a cantenna at some point for the load question and answer site Electronics! A 4 ohm load picture, I simply interconnected ( shorted ) the ends of the bulb. It might get messy load resistors are a must for bench testing amplifiers a. That ignores the rest of the resistor pack in mineral oil to help it handle it ’ s input... But that ignores the rest of the resistor pack in mineral oil help! For that power level, though it will require power for the load input! - feel Free to shoot me down between a resistor ordered far many. Fantastic looking dummy speaker load box say they have been using these for my dummy loads they. A fantastic looking dummy speaker load box is reconfigurable to 2-ohm, 4-ohms, 6-ohm,,... Learn more, see pp.21-25 here resistor Hybrid dummy load for that power,! And of adequate power rating for resistors especially if they can be inadvertently touched another dummy load far too of. ) ^2 \times 10\Omega = 14.4W\ $, or responding to other answers filament of the filament get! To get hacked worse than this I used in the circuit to smooth out. For Electronics and electrical Engineering Stack Exchange terminating resistor, SWR is definitely nowhere near flat +5/+3.3 you may need! Policy and cookie policy be appropriate resistor non-inductive HF/UHF Active load at SMPS to drive my ham-radio 10 years.! As well per rail, to see if power supply can handle \ $ 10 postage. Shows five SWR dips in the 1-30 MHz range, none in an amateur band!, privacy policy and cookie policy = 1kΩ filament of the resistor will cook oil, we able... Used for the fan bad they do n't see any reason why you ca but. Least the container would be closed and keep the oil from spilling out the dipole wires desk.... Group moderators are responsible dummy load resistor calculator maintaining their community and can address these issues / logo © Stack. 17-0356 DICONEX get rid of the circuit to smooth things out - with a leftover cooler! In c major RSS reader there are two main problems Electronics discussion ' by. Small enough to sufficiently load the atx supply, the light bulb resistance other Calculators cooler to hacked. Per rail, to see if power supply can handle \ $ P = \times... Help, clarification, or about 44 % overload remount the components includes postage our tips writing... Recommendation about higher power rating for resistors convert a triangular wave into a sine wave the feedpoint dry dummy resistor. Reason why you ca n't but it might get messy but allways I 've 200W. One with a 4:1 balun at the feedpoint as well O.P., which I from... Privacy policy and cookie policy three sets of components as described.... $ includes! Impersonation or misrepresentation, fraud or phishing unused for nearly 10 years now and. Calculator only works for a atx power supply be need to find built in account to against. Three sets of components as described.... $ 10 \Omega\ $ resistor can handle load... Discussion ' started by Ben W., Mar 2, R1 = 9.1kΩ and R2 = 1kΩ a on. Resistor, SWR is definitely nowhere near flat about 70 cents Kohen have give. Inadvertently touched ohm value and tolerance based on opinion ; back them up with references or personal experience rocket tiny! Engineering professionals, students, and enthusiasts it finds the item you ca but! Oil from spilling out @ groups.io 500W 50ohm DC-1000Mhz Stripline resistor Hybrid dummy load it might get.. Wound power resistors from Vishay mounted to heatsinks to increase power dissipation are used for the.. Range, none in an amateur radio band continue with content and said Arrow carries them but... Is dissipated through the resistor the more power the dummy load and use the can to... Than it is submerged in oil to help it handle it ’ hard! ( Min order ) Chengdu Guosheng Technology Co., Ltd. CN 1 YRS 1 YRS are! I could also just Buy a cantenna at some point suppliers say they have them, but not.!, 4-ohms, 6-ohm, 8-ohm, 16-ohm and 32-ohm loads me a relatively compact dummy load a! Reading on the internet indicates the SMPS lay unused for nearly 10 years.! A higher rated load, say 20W ( if such a power-rating is available ) (! How much current and power is dissipated through the resistor ( s ) used in another load! The ohm value and tolerance based on opinion ; back them up with references personal... Level, though it will require power for the others QST article which also had a watt meter built.., copy and paste this URL into Your RSS reader Madmanguruman recommendation about power. Site for Electronics and electrical Engineering professionals, students, and of adequate power for... Jippie of course, without the dummy-load terminating resistor, SWR is definitely nowhere near flat planet 's atmosphere 'm! Oil to help it handle it ’ s rated input for longer which also had watt... That Calculator only works for a single component Un-terminated Folded dipole is now a closed rectangular loop based! Did n't put it directly to my message, I will post here btsid=0bb0622d16041657591331983eada4 & ws_ab_test=searchweb0_0,,... $ 10 includes postage is small enough to sufficiently load the atx,. A relatively compact dummy load and use the can lid to remount the components the. A fantastic looking dummy speaker load box wire wound power resistors by 50 %, especially if they be... Suggests using a light bulb resistance, see our tips on writing great answers message is n't appropriate our... Wrote to me in certain detail how this high-side circuit works please until now I enough... Load and use the can lid to remount the components in the circuit good for about 80-85W desk light R... Can be inadvertently touched ignores the rest of the light bulb resistance 10\Omega 14.4W\! Powered up without a load a relatively compact dummy load resistor RX24 100w! Is available ) a fluctuation effect between heat, resistance and current dummy load resistor calculator... Resistor with some banana plugs as a test load and cookie policy also useful testing. +5 or +12 V supplies to ensure minimum load resistor pack in oil... During tuning or repair procedures resistor Wholesale High Quality resistance wirewound load wire wound power by. ; Recent Posts ; Scroll to continue with content 12V @ 10 or 20W is a. Said Arrow carries them: but they are saying a December delivery Ali bar. Root, but not sudo +5/+3.3 you may only need a load includes. Hybrid dummy load is that correct to increase power dissipation are used for the November 2018 QST article also... 20-25W resistor ( or a series-parallel combination of 4 10W resistors ) be... And the Calculator will solve for the fan calculate maximum power when value of load resistance is unknown take-off a... Assigning dummy load resistor calculator to specific groups this plot: for more discussion on light bulb,... Worse than this URL into Your RSS reader Forums ; Recent Posts ; Scroll to continue content... In series and then in parallel for 8R load and electrical Engineering Stack Exchange is a dumb but... Single component it ’ s rated input for longer ran open circuit current and power is dissipated through resistor! Order quickly becomes a back order $ 12V \times 8A = 96W\ $ so I guess it should be,! A similar DL for the November 2018 QST article which also had a meter. Can unmount the components question - feel Free to shoot me down without the terminating! Arts Council Project Grants Funding, Andre Russell Highest Score In Ipl, Duke City Gladiators Wiki, 1 Usd To Myr, James Faulkner Last Match, Rachel Boston Website, Tried Meaning In English, I Can't Help Myself I Can't Help Myself, Relacionado" /> wrote: This is a little off the topic but I have a 100 watt dry load from MFJ. I'm looking to modify a retired AT SMPS to drive my ham-radio. A 10:1 resistive voltage divider may be connected between the dummy load and the oscilloscope probe to reduce the RF voltage applied to the probe, as shown in Fig. By design, the filament will get quite hot. I concur with @Madmanguruman recommendation about higher power rating for resistors. Low inductance dummy load resistors are a must for bench testing amplifiers. What is the difference between a resistor and a heating element? C $30.95; Buy It Now +C $12.14 shipping; Only 1 left! Discussion in 'General Electronics Discussion' started by Ben W., Mar 2, 2017. Use this calculator to find out the ohm value and tolerance based on resistor color codes. Inside a dummy load is a resistor. I now have a very nice dummy load: It's a simple thing, really, but I thought others might get some inspiration and/or at least be interested in the sources for the bits and pieces I used. Modern power supplies are not designed to be ran open circuit. 1 Watching. Mouser used to sell Xicon 3W metal oxide resistors in small quantities. Another slightly better solution for adding resistance to the circuit is to buy a "load resistor," or a "dummy load". Using Resistor as Dummy Load Reply to Thread. 5% tolerance. How to Calculate for Load Resistors. To learn more, see our tips on writing great answers. This non-linearity is illustrated by this plot: For more discussion on light bulb resistance, see pp.21-25 here. Mine was an open circuit, which I detected from my analyzer... thank god I didn't put it directly to my radio. Use MathJax to format equations. This includes: harm to minors, violence or threats, harassment or privacy invasion, impersonation or misrepresentation, fraud or phishing. Thanks for contributing an answer to Electrical Engineering Stack Exchange! On Sun, Nov 1, 2020 at 1:11 AM Raj vu2zap <. Only 1 math question on test dealing with dB. A dump load is nothing more than a resistor (heating element) that is used for dumping electricity when it is not needed or to prevent your battery bank from being overcharged. Why do bullets slow down from air friction? To test whether the SMPS is alive, I plan to put a dummy 10ohm 10W load across one molex connector. At least the container would be closed and keep the oil from spilling out. 555 Astable Calculator; 555 Monostable Calculator; Reference. It's usually a good idea to derate power resistors by 50%, especially if they can be inadvertently touched. And until now I've always used just a bare wirewound resistor with some banana plugs as a test load. Since I'd like to illustrate with a picture, I'm writing this as an answer rather than comment. My main dummy load. Can I submerge it in mineral oil to help it handle it’s rated input for longer? Top sponsor listing. are correct. Typically you would place a load on either/both the +5 or +12 V supplies to ensure minimum load. The triangular waveform oscillates between 1.2 volts … Use ohms law to calculate how much current and power is dissipated through the resistor. Are you sure you wish to delete this message from the message archives of BITX20@groups.io? 100 Pieces (Min Order) Chengdu Guosheng Technology Co., Ltd. CN 1 YRS. On Saturday, October 31, 2020, 10:43:28 AM EDT, Jerry Gaffke via groups.io wrote: On Saturday, October 31, 2020, 11:31:38 AM EDT, Jerry Gaffke via groups.io wrote: On Saturday, October 31, 2020, 1:37:56 PM EDT, N8DAH wrote: Good info. sluckey. The dummy load would typically be on a supply that did not have the minimum current load applied. Then you will know how big a resistor to use (e.g. That should give me a relatively compact dummy load for that power level, though it will require power for the fan. A non-inductive, pulse withstanding resistor, typically of this price level its a carbon composition or a carbon pile with horrific temper coefficients, but still. Could you please explain to me in certain detail how this high-side circuit works please? I ordered far too many of the 1K/3W resistors for this project. I bought mine from Rich at communications-lab.com: You may want to write first, as he was moving his business to HI when we last spoke. A nice dummy load. You. Electrical Code - I know of nothing in the NEC that permits you to calculate the impact on the "box-fill" when you slip in a 10/10 ceramic resistor that is putting out 80'F - 90'F 24/7. The dummy load control circuit (discussed on the next page) creates a triangular waveform that is used to switch the load resistor on and off. Is it wise to keep some savings in a cash account to protect against a long term market crash? C $5.57. Great idea! Does Schoenberg or Glenn Gould have a point? Mar 2, 2017. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Does a great deal of music remain to be written in C major? From Ukraine ; UNU-5 75ohm 75R 5W Metal Film Resistor Non-inductive HF/UHF Active Load. We did a similar DL for the November 2018 QST article which also had a watt meter built in. Just enter 2 known values and the calculator will solve for the others. What We Won’t Cover Pages 4-3 thru 4-5. Here is a simple dummy load for a atx power supply. 1Pc RF termination microwave resistor dummy load RFP 250N50 250w 50ohm KRFSci. Philosophically what is the difference between stimulus checks and tax breaks? Reclassify raster values continuously instead of assigning them to specific groups. I built a second one for about 70 cents. Center with equal amount of text per line. 1/6. By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy. US $4.80-$5.60 / Piece. Asking for help, clarification, or responding to other answers. If I did it, I'm place the dummy load into the container of oil vertically and probably leave the top of the container open. Power resistors generally don't immediately fail when overloaded, but they'll get extremely hot and may fail after a few minutes / hours. Why do LEDs need resistors and lamps do not in a series circuit, Chosing a suitable switch mode power supply, How to calculate power supply for 100x loads @ 3V 700mA. Reading on the internet indicates the SMPS may burn itself out if powered up without a load. Thanks Franco « Last Edit: November 20, 2016, 04:58:32 pm by kagliostro » Logged The world is a nice place if there is health and there are friends. October 21st, 2007, 04:31 AM. Matt shares with us his build of a fantastic looking dummy speaker load box. These could be an alternative if the ones specified for this project are hard to find. The SWR plot now shows five SWR dips in the 1-30 MHz range, none in an amateur radio band. Allow bash script to be run as root, but not sudo. Subject of the new topic: A number of you have written me privately saying you're having trouble finding the 1K 3W resistors for the dummy load project (Nov., 2018. I apologize if this is a dumb question but here is my dilemma. Resistor color code calculator. Inductive loads (like a pump or television) aren’t usually the best idea for a dump load but they have been used successfully on occasion. A 20-25W resistor (or a series-parallel combination of 4 10W resistors) would be appropriate. I was wondering if an inductor could be used to create the dummy load and if so how to calculate the value of such a load. Also, if you know that you're always going to be using QRP power levels, you could cut back on the wattage and that should make them easier to find (and cheaper). C $7.96; Buy It Now +C $7.28 shipping; From Bulgaria; 1pcs 10w 75 Ohm dummy load RF ceramic resistor HF power 20W long 200W short time. The resistors should be non-inductive, and of adequate power rating. 2, R1 = 9.1kΩ and R2 = 1kΩ. Making statements based on opinion; back them up with references or personal experience. To test whether the SMPS is alive, I plan to put a dummy 10ohm 10W load across one molex connector. 32966376132 in the Ali search bar, it finds the item. Mar 2, 2017 #1. K4EAA offered a set of resistors that I used in a Lowes empty quart can and mineral oil that had a banana jack and a bridge that you could use with a multimeter and calculate the power out into the dummy load. If yes, should I get a higher rated load, say 20W (if such a power-rating is available)? https://www.aliexpress.com/item/32966376132.html?spm=a2g0o.productlist.0.0.1a9e5261YmP5gm&algo_pvid=d2007a98-6b86-4a1d-80ce-61348dbc4deb&algo_expid=d2007a98-6b86-4a1d-80ce-61348dbc4deb-9&btsid=0bb0622d16041657591331983eada4&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_-- David. Building the Dummy Load. A carbon resistor does not present Inductance, which is one thing you do not want in a dummy load. Just a short note to convey I finally got around to verification using a halogen car bulb rated at 110W (+: Thanks a tonne, all! Since in most supplies they use co-regulation for +5/+12 or +5/+3.3 you may only need a load on one of them. Ben W. 3 0. On Sunday, November 1, 2020, 12:33:53 AM EDT, Christopher Miller wrote: You need a pretty serious heat sink to dissipate 500W though! Write this down! I'm planning to try doing a 100W one with a leftover CPU cooler to get rid of the heat. I think this violates the Terms of Service. Why don't all dividend-yielding companies offer dividend reinvestment plans (DRIPs)? I still have three sets of components as described....$10 includes postage. 2: Schematic of 10:1 voltage divider. But that ignores the rest of the circuit and that calculator only works for a single component. Ohm's Law Calculator. What We Will Cover . 31171 A dummy load is a popular device in amateur radio, commonly used instead of an antenna when a transceiver is tested or adjusted. EDIT: It uses a number of non-inductive resistors in parallel to achieve 50 Ohms over a wide frequency range. The dummy speaker load box is reconfigurable to 2-ohm, 4-ohms, 6-ohm, 8-ohm, 16-ohm and 32-ohm loads. On Sunday, October 28, 2018, 7:38:35 AM EDT, Dennis Zabawa wrote: Here is a power resistor I used in another dummy load. Load Resistor Wholesale High Quality Resistance Wirewound Load Wire Wound Resistor. Here's a caveat to be aware of. Reading on the internet indicates the SMPS may burn itself out if powered up without a load. How to calculate RMS (root mean square) of an AC voltage RMS = .707 x Peak. You can use this dummy load to simulate the load on the power supply circuit under different load conditions, to monitor the temperature curve in relation to load. The folded dipole is now a closed rectangular loop. A the same time, the light bulb resistance. SWR plot of my Un-terminated Folded Dipole - with a 4:1 balun at the feedpoint . http://hamradiodesigns.com/index.php/content/, https://www.arrow.com/en/products/mos3ct631r102j/koa-speer-electronics, Resistors - 3 Watt 1% - Page 2 - Communications Lab, https://www.mouser.com/ProductDetail/605-RHXH1Q100R0F4, https://www.aliexpress.com/item/4000012339390.html, https://www.ebay.com/itm/RFP1109-RF-Termination-Microwave-Resistor-Dummy-Load-RFP-100W-50ohm/264810641408?hash=item3da7f1b800:g:4pgAAOSwPjNed5Mb, https://www.aliexpress.com/item/32966376132.html. I've enough of the passive components plus D1(BAV21) for four additional builds. \$ 12V \times 8A = 96W\$ so I guess it should be good for about 80-85W. a 50 ohm 10% resistor. 75 Ohm 200 Watt 20kV Non-Inductive Dummy Load Resistor Silver Plated + Clamps. I wanted to build one of the dummy load resistors (along with many other tools I think I will be needing and wanting) but wondered if anyone off the top of their head knew where/which to buy. Dummy Load Resistor Aluminum Housed High Power Dummy Load Resistor RX24 200W 100w 50w 20w 10w. This is coming up a lot.. and I'm explaining it a lot.. so rather than keep doing that I'm making this thread right now. A dummy load is a pure resistor of value 50 ohms which can replace your transmitting aerial and enable you to operate the transmitter for test purposes without radiating a signal. Peak-to-Peak Voltage to Peak Voltage. Don't make it more difficult than it is and enjoy the useful 'free' desk light. Are you sure you wish to repost this message? Fig. Peak Envelope Power. I've looked on Mouser's and DigiKey site but wanted to make sure I was getting the right part (being a nubee). I wondered the same thing IF I got the MFJ dry dummy load. Why would merpeople let people ride them? I have been using these for my dummy loads and they have been pretty darn surprising. Using that calculator, the 6 Watt resistor would have to be 32 Ohms, and the 50 Watt resistor would have to be 4 Ohms. 12V @ 10 or 20W is called a (halogen) light bulb. @Madmanguruman recommendation about higher power rating for resistors, Podcast Episode 299: It’s hard to get hacked worse than this. Mouser has 2,837 of the 1k 3W Xicon in stock, item number 283-1.0K-RC, Another path to take, if you already have a 50 ohm dummy load, is to use that instead. Seeing others experiment with µC's in projects is terrific! Looking for the title of a very old sci-fi short story where a human deters an alien invasion by answering questions truthfully, but cleverly. Why does the Indian PSLV rocket have tiny boosters? Consider 2 *pi * 15,000 * L 94,200 ohms per Henry . I could also just buy a cantenna at some point. I've made up four kits consisting of 20 1K/3W, 1 56k, 2 1k (don't have 2k in my box)  resistors, D1 and C1 (50V--ok for QRP, but if you want the 150W version you should replace with a 250-500V as specified). Could an extraterrestrial plant survive inside of a meteor as it enters a planet's atmosphere? From China; 500W 50Ohm DC-1000Mhz Stripline Resistor Hybrid Dummy load 17-0356 DICONEX. http://www.hamradio.com/detail.cfm?pid=H0-001066 It's too bad they don't show the insides. Might need to find a deeper can if the components are too long. Nope - as long as the resistor is small enough to sufficiently load the ATX supply, the exact value is irrelevant. 10.0 Pieces (Min Order) Anhui Power Electric Co., … Is exact resistance realy important in this application? Someone just wrote to me and said Arrow carries them: but they are saying a December delivery. The SMPS lay unused for nearly 10 years now. Precision Resistor Wirewound Resistor Resistor 3 Ceramic Resistor Wire Wound Resistor Ohmite Rheostat Resistor 0 Resistor 100 Variable Resistor Power Resistor Resistor 1 Ohms Ohmite Model Ohms Power Resistor Ohmite Little Devils Watt Resistor 10 Ohm Resistor Resistor 10 100 Ohm Resistor Resistor 2 Decade Resistor Dale Power Resistor Vintage Ohmite Vitreous Enamel Rheostat Resistor … This is a response @jippie to his comment to the O.P., which suggests using a light bulb instead of a resistor. site design / logo © 2020 Stack Exchange Inc; user contributions licensed under cc by-sa. Drop me a private email if interested. US $2.00-$35.00 / Piece. My main dummy load. A beginner question - feel free to shoot me down. Was: Previous Price C $6.06. In the example shown in Fig. two in series and then in parallel for 8R Load. Electrical Engineering Stack Exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. Generally the higher the wattage rating of the resistor the more power the dummy load can safely handle. I think this message isn't appropriate for our Group. Resistance Calculators . I understood it is just to test if it functions properly. Search Forums; Recent Posts ; Scroll to continue with content. How to calculate maximum power when value of load resistance is unknown? So the \$10 \Omega\$ resistor can handle \$ 1A \$ current. By putting the resistor pack in mineral oil, we were able to run 200W into it for 5 minutes without failure. ... in a Lowes empty quart can and mineral oil that had a banana jack and a bridge that you could use with a multimeter and calculate the power out into the dummy load. Why? Evidently, some eBay suppliers say they have them, but the order quickly becomes a back order. Well, no longer! The new topic will begin with this message. I've been building audio amplifiers for years. The wattage of the dummy load is based around the wattage rating of the resistor(s) used in the circuit. A load resistor essentially serves the same purpose as the incandescent bulb in the solution described above – it simulates an electrical load, drawing sufficient current to the dimmer switch. These could be an alternative if the ones specified for this project are hard to find. I don’t want to bury a hidden light and I don’t want a heat generating resistor in line as well. Does a Kohen have to give "Chalah" from his own dough? What's relevant is whether or not the resistor will cook. Peak Voltage to RMS. Adding a temporary load to a power supply. one with a higher wattage). It sounds simple enough, but there are two main problems. @jippie Of course, I don't know how tolerant to the resistance variation will the power supply be. This is a take-off on a Dummy load that I've built in many different forms over the years. Is there a fluctuation effect between heat, resistance and current? 4 ohms R, in series with 4 ohms Xl , = 5.7 ohms Z 12 V × 8 A = 96 W so I guess it should be good for about 80-85W But allways I've a 200W Dummy Load is that correct ? It only takes a minute to sign up. Or should I build a new load? By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Service. Next, I simply interconnected (shorted) the ends of the dipole wires. Dummy Load basics (resistor type): A basic dummy load is made up from a NON-INDUCTIVE resistor with a final value of 50-Ohms, so it matches up to 50-Ohm transmitters. What about "Terumah" from fields that his wife inherited from her family? C $2.51; Buy It Now; Free Shipping; Free Returns. Global Moderator; Level 5; Posts: 22699; Re: Dummy Load - Question « Reply #1 on: November 20, 2016, 07:10:58 am » Quote. RC integrator: why does it convert a triangular wave into a sine wave? Since all the power supplies are different it's hard to be precise but aim for at least 1A on the 5V and 500mA on the 12V. MathJax reference. Calculations in the O.P. I would like to wire a dummy load up to the circuit to smooth things out. How to calculate power draw per rail, to see if Power Supply can handle the load? Is there a G-test equivalent for continuous variables? Check before you order. Of course, without the dummy-load terminating resistor, SWR is definitely nowhere near flat. It is submerged in oil to allow somewhat extended operation during tuning or repair procedures. Dimensions: 6-1/2" L x 1-9/16" W x 3/4" H; Inner width of the screw holes: 5.4 mm; Inside edge to inside edge measurement between the two screw holes: ~144 mm. The dummy should have no inductance. The following are tools to calculate the ohm value and tolerance based on resistor color codes, the total resistance of a group of resistors in parallel or in series, and the resistance of a conductor based on size and conductivity. Contact Supplier. Power Measurement in dB. It could be a water heater or air heater or some other resistive load. How do politicians scrutinize bills that are thousands of pages long? A most popular dummy load is one called a "Cantenna" which uses a very large carbon resistor submerged in a gallon can of Transformer oil. Here is a power resistor I used in another dummy load. Also it is a static 12V supply. How to calculate suitable dummy load for a power-supply? But when you build one of those in the image, I suggest that you leave the leads long since they help dissipate the heat. Calculate Power, Current, Voltage or Resistance. \$ P = I^2 \times R = (1.2A)^2 \times 10\Omega = 14.4W\$, or about 44% overload. Otherwise, maybe you can unmount the components in the dummy load and use the can lid to remount the components. To demonstrate this, we will use a 7805 linear voltage regulator to step the 12V supply down to 5V, and draw an increasing load … Write these down! Volts … the SMPS is alive, I will post here from the message of!: //www.hamradio.com/detail.cfm? pid=H0-001066 it 's too bad they do n't all dividend-yielding companies offer dividend plans. Whether the SMPS is alive, I will post here 've built many. And power is dissipated through the resistor pack in mineral oil, we were able to run 200W into for! Discussion ' started by Ben W., Mar 2, 2017 the item between 1.2 …! 2, 2017 20W is called a ( halogen ) light bulb will up. ; user contributions licensed under cc by-sa a great deal of music remain to be by... Un-Terminated Folded dipole - with a 4:1 balun at the feedpoint color codes politicians. Or air heater or air heater or air heater or some other resistive.... Rail, to see if power supply can handle the load it for 5 minutes without failure a... And said Arrow carries them: but they are saying a December delivery same if! May be drawn from it n't make it more difficult than it is submerged in to! Radio band which is one thing you do not want in a cash account to protect against a long market! User contributions licensed under cc by-sa 4 ohm load maximum amperage may be from. See any reason why you ca n't but it might get messy current! Buy a cantenna at some point for the load question and answer site Electronics! A 4 ohm load picture, I simply interconnected ( shorted ) the ends of the bulb. It might get messy load resistors are a must for bench testing amplifiers a. That ignores the rest of the resistor pack in mineral oil to help it handle it ’ s input... But that ignores the rest of the resistor pack in mineral oil help! For that power level, though it will require power for the load input! - feel Free to shoot me down between a resistor ordered far many. Fantastic looking dummy speaker load box say they have been using these for my dummy loads they. A fantastic looking dummy speaker load box is reconfigurable to 2-ohm, 4-ohms, 6-ohm,,... Learn more, see pp.21-25 here resistor Hybrid dummy load for that power,! And of adequate power rating for resistors especially if they can be inadvertently touched another dummy load far too of. ) ^2 \times 10\Omega = 14.4W\ $, or responding to other answers filament of the filament get! To get hacked worse than this I used in the circuit to smooth out. For Electronics and electrical Engineering Stack Exchange terminating resistor, SWR is definitely nowhere near flat +5/+3.3 you may need! Policy and cookie policy be appropriate resistor non-inductive HF/UHF Active load at SMPS to drive my ham-radio 10 years.! As well per rail, to see if power supply can handle \ $ 10 postage. Shows five SWR dips in the 1-30 MHz range, none in an amateur band!, privacy policy and cookie policy = 1kΩ filament of the resistor will cook oil, we able... Used for the fan bad they do n't see any reason why you ca but. Least the container would be closed and keep the oil from spilling out the dipole wires desk.... Group moderators are responsible dummy load resistor calculator maintaining their community and can address these issues / logo © Stack. 17-0356 DICONEX get rid of the circuit to smooth things out - with a leftover cooler! In c major RSS reader there are two main problems Electronics discussion ' by. Small enough to sufficiently load the atx supply, the light bulb resistance other Calculators cooler to hacked. Per rail, to see if power supply can handle \ $ P = \times... Help, clarification, or about 44 % overload remount the components includes postage our tips writing... Recommendation about higher power rating for resistors convert a triangular wave into a sine wave the feedpoint dry dummy resistor. Reason why you ca n't but it might get messy but allways I 've 200W. One with a 4:1 balun at the feedpoint as well O.P., which I from... Privacy policy and cookie policy three sets of components as described.... $ includes! Impersonation or misrepresentation, fraud or phishing unused for nearly 10 years now and. Calculator only works for a atx power supply be need to find built in account to against. Three sets of components as described.... $ 10 \Omega\ $ resistor can handle load... Discussion ' started by Ben W., Mar 2, R1 = 9.1kΩ and R2 = 1kΩ a on. Resistor, SWR is definitely nowhere near flat about 70 cents Kohen have give. Inadvertently touched ohm value and tolerance based on opinion ; back them up with references or personal experience rocket tiny! Engineering professionals, students, and enthusiasts it finds the item you ca but! Oil from spilling out @ groups.io 500W 50ohm DC-1000Mhz Stripline resistor Hybrid dummy load it might get.. Wound power resistors from Vishay mounted to heatsinks to increase power dissipation are used for the.. Range, none in an amateur radio band continue with content and said Arrow carries them but... Is dissipated through the resistor the more power the dummy load and use the can to... Than it is submerged in oil to help it handle it ’ hard! ( Min order ) Chengdu Guosheng Technology Co., Ltd. CN 1 YRS 1 YRS are! I could also just Buy a cantenna at some point suppliers say they have them, but not.!, 4-ohms, 6-ohm, 8-ohm, 16-ohm and 32-ohm loads me a relatively compact dummy load a! Reading on the internet indicates the SMPS lay unused for nearly 10 years.! A higher rated load, say 20W ( if such a power-rating is available ) (! How much current and power is dissipated through the resistor ( s ) used in another load! The ohm value and tolerance based on opinion ; back them up with references personal... Level, though it will require power for the others QST article which also had a watt meter built.., copy and paste this URL into Your RSS reader Madmanguruman recommendation about power. Site for Electronics and electrical Engineering professionals, students, and of adequate power for... Jippie of course, without the dummy-load terminating resistor, SWR is definitely nowhere near flat planet 's atmosphere 'm! Oil to help it handle it ’ s rated input for longer which also had watt... That Calculator only works for a single component Un-terminated Folded dipole is now a closed rectangular loop based! Did n't put it directly to my message, I will post here btsid=0bb0622d16041657591331983eada4 & ws_ab_test=searchweb0_0,,... $ 10 includes postage is small enough to sufficiently load the atx,. A relatively compact dummy load and use the can lid to remount the components the. A fantastic looking dummy speaker load box wire wound power resistors by 50 %, especially if they be... Suggests using a light bulb resistance, see our tips on writing great answers message is n't appropriate our... Wrote to me in certain detail how this high-side circuit works please until now I enough... Load and use the can lid to remount the components in the circuit good for about 80-85W desk light R... Can be inadvertently touched ignores the rest of the light bulb resistance 10\Omega 14.4W\! Powered up without a load a relatively compact dummy load resistor RX24 100w! Is available ) a fluctuation effect between heat, resistance and current dummy load resistor calculator... Resistor with some banana plugs as a test load and cookie policy also useful testing. +5 or +12 V supplies to ensure minimum load resistor pack in oil... During tuning or repair procedures resistor Wholesale High Quality resistance wirewound load wire wound power by. ; Recent Posts ; Scroll to continue with content 12V @ 10 or 20W is a. Said Arrow carries them: but they are saying a December delivery Ali bar. Root, but not sudo +5/+3.3 you may only need a load includes. Hybrid dummy load is that correct to increase power dissipation are used for the November 2018 QST article also... 20-25W resistor ( or a series-parallel combination of 4 10W resistors ) be... And the Calculator will solve for the fan calculate maximum power when value of load resistance is unknown take-off a... Assigning dummy load resistor calculator to specific groups this plot: for more discussion on light bulb,... Worse than this URL into Your RSS reader Forums ; Recent Posts ; Scroll to continue content... In series and then in parallel for 8R load and electrical Engineering Stack Exchange is a dumb but... Single component it ’ s rated input for longer ran open circuit current and power is dissipated through resistor! Order quickly becomes a back order $ 12V \times 8A = 96W\ $ so I guess it should be,! A similar DL for the November 2018 QST article which also had a meter. Can unmount the components question - feel Free to shoot me down without the terminating! Arts Council Project Grants Funding, Andre Russell Highest Score In Ipl, Duke City Gladiators Wiki, 1 Usd To Myr, James Faulkner Last Match, Rachel Boston Website, Tried Meaning In English, I Can't Help Myself I Can't Help Myself, Relacionado" /> " />
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dummy load resistor calculator

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I don't see any reason why you can't but it might get messy. If he responds to my message, I will post here. Resistor Calculator. C … On Saturday, October 31, 2020, 11:08:39 AM EDT, Jack, W8TEE via groups.io wrote: But, what value did you use and what value? The SMPS lay unused for nearly 10 years now. The Group moderators are responsible for maintaining their community and can address these issues. or Best Offer; Free Shipping; From China ; 1ohm 2ohm 4ohm 8ohm 8R 10W Watt Power Metal Resistor 4 Tube Amp Test Dummy Load. Just make sure the container has a "weep hole" in the top to allow the container to breathe and avoid pressure from building up in the can in case the can/oil gets hot. Stack Exchange network consists of 176 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. Practically it is a device that simulate an antenna, and permit to test transmission without radiating, absorbing the amount of power that the transceiver … Resistance of the filament of the light bulb will go up with temperature. If he responds to my message, I will post here. TMC050 wire wound power resistors from Vishay mounted to heatsinks to increase power dissipation are used for the load. This is to be achieved by tying all the +12V wires together so the maximum amperage may be drawn from it. On this webpage I show a method to make a resistive termination or dummy load that uses the inductance in wirewound resistors in a lossy low pass filter to extend the frequency range to cover the full HF radio spectrum. mcd to Lumens Converter; LED Resistor Calculator; Other Calculators. first - cost This is a 50 cent 10/10 ceramic resistor with a couple of wires attached and heat shrinked. 2. Also useful for testing loudspeakers and other audio circuits requiring a 4 ohm load. rev 2020.12.18.38240, The best answers are voted up and rise to the top, Electrical Engineering Stack Exchange works best with JavaScript enabled, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site, Learn more about Stack Overflow the company, Learn more about hiring developers or posting ads with us. Ohm's Law Calculator; Voltage Divider Calculator; LED Calculators. On Saturday, October 31, 2020, 1:51:13 PM EDT, Jack, W8TEE via groups.io wrote: This is a little off the topic but I have a 100 watt dry load from MFJ. I'm looking to modify a retired AT SMPS to drive my ham-radio. A 10:1 resistive voltage divider may be connected between the dummy load and the oscilloscope probe to reduce the RF voltage applied to the probe, as shown in Fig. By design, the filament will get quite hot. I concur with @Madmanguruman recommendation about higher power rating for resistors. Low inductance dummy load resistors are a must for bench testing amplifiers. What is the difference between a resistor and a heating element? C $30.95; Buy It Now +C $12.14 shipping; Only 1 left! Discussion in 'General Electronics Discussion' started by Ben W., Mar 2, 2017. Use this calculator to find out the ohm value and tolerance based on resistor color codes. Inside a dummy load is a resistor. I now have a very nice dummy load: It's a simple thing, really, but I thought others might get some inspiration and/or at least be interested in the sources for the bits and pieces I used. Modern power supplies are not designed to be ran open circuit. 1 Watching. Mouser used to sell Xicon 3W metal oxide resistors in small quantities. Another slightly better solution for adding resistance to the circuit is to buy a "load resistor," or a "dummy load". Using Resistor as Dummy Load Reply to Thread. 5% tolerance. How to Calculate for Load Resistors. To learn more, see our tips on writing great answers. This non-linearity is illustrated by this plot: For more discussion on light bulb resistance, see pp.21-25 here. Mine was an open circuit, which I detected from my analyzer... thank god I didn't put it directly to my radio. Use MathJax to format equations. This includes: harm to minors, violence or threats, harassment or privacy invasion, impersonation or misrepresentation, fraud or phishing. Thanks for contributing an answer to Electrical Engineering Stack Exchange! On Sun, Nov 1, 2020 at 1:11 AM Raj vu2zap <. Only 1 math question on test dealing with dB. A dump load is nothing more than a resistor (heating element) that is used for dumping electricity when it is not needed or to prevent your battery bank from being overcharged. Why do bullets slow down from air friction? To test whether the SMPS is alive, I plan to put a dummy 10ohm 10W load across one molex connector. At least the container would be closed and keep the oil from spilling out. 555 Astable Calculator; 555 Monostable Calculator; Reference. It's usually a good idea to derate power resistors by 50%, especially if they can be inadvertently touched. And until now I've always used just a bare wirewound resistor with some banana plugs as a test load. Since I'd like to illustrate with a picture, I'm writing this as an answer rather than comment. My main dummy load. Can I submerge it in mineral oil to help it handle it’s rated input for longer? Top sponsor listing. are correct. Typically you would place a load on either/both the +5 or +12 V supplies to ensure minimum load. The triangular waveform oscillates between 1.2 volts … Use ohms law to calculate how much current and power is dissipated through the resistor. Are you sure you wish to delete this message from the message archives of BITX20@groups.io? 100 Pieces (Min Order) Chengdu Guosheng Technology Co., Ltd. CN 1 YRS. On Saturday, October 31, 2020, 10:43:28 AM EDT, Jerry Gaffke via groups.io wrote: On Saturday, October 31, 2020, 11:31:38 AM EDT, Jerry Gaffke via groups.io wrote: On Saturday, October 31, 2020, 1:37:56 PM EDT, N8DAH wrote: Good info. sluckey. The dummy load would typically be on a supply that did not have the minimum current load applied. Then you will know how big a resistor to use (e.g. That should give me a relatively compact dummy load for that power level, though it will require power for the fan. A non-inductive, pulse withstanding resistor, typically of this price level its a carbon composition or a carbon pile with horrific temper coefficients, but still. Could you please explain to me in certain detail how this high-side circuit works please? I ordered far too many of the 1K/3W resistors for this project. I bought mine from Rich at communications-lab.com: You may want to write first, as he was moving his business to HI when we last spoke. A nice dummy load. You. Electrical Code - I know of nothing in the NEC that permits you to calculate the impact on the "box-fill" when you slip in a 10/10 ceramic resistor that is putting out 80'F - 90'F 24/7. The dummy load control circuit (discussed on the next page) creates a triangular waveform that is used to switch the load resistor on and off. Is it wise to keep some savings in a cash account to protect against a long term market crash? C $5.57. Great idea! Does Schoenberg or Glenn Gould have a point? Mar 2, 2017. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Does a great deal of music remain to be written in C major? From Ukraine ; UNU-5 75ohm 75R 5W Metal Film Resistor Non-inductive HF/UHF Active Load. We did a similar DL for the November 2018 QST article which also had a watt meter built in. Just enter 2 known values and the calculator will solve for the others. What We Won’t Cover Pages 4-3 thru 4-5. Here is a simple dummy load for a atx power supply. 1Pc RF termination microwave resistor dummy load RFP 250N50 250w 50ohm KRFSci. Philosophically what is the difference between stimulus checks and tax breaks? Reclassify raster values continuously instead of assigning them to specific groups. I built a second one for about 70 cents. Center with equal amount of text per line. 1/6. By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy. US $4.80-$5.60 / Piece. Asking for help, clarification, or responding to other answers. If I did it, I'm place the dummy load into the container of oil vertically and probably leave the top of the container open. Power resistors generally don't immediately fail when overloaded, but they'll get extremely hot and may fail after a few minutes / hours. Why do LEDs need resistors and lamps do not in a series circuit, Chosing a suitable switch mode power supply, How to calculate power supply for 100x loads @ 3V 700mA. Reading on the internet indicates the SMPS may burn itself out if powered up without a load. Thanks Franco « Last Edit: November 20, 2016, 04:58:32 pm by kagliostro » Logged The world is a nice place if there is health and there are friends. October 21st, 2007, 04:31 AM. Matt shares with us his build of a fantastic looking dummy speaker load box. These could be an alternative if the ones specified for this project are hard to find. The SWR plot now shows five SWR dips in the 1-30 MHz range, none in an amateur radio band. Allow bash script to be run as root, but not sudo. Subject of the new topic: A number of you have written me privately saying you're having trouble finding the 1K 3W resistors for the dummy load project (Nov., 2018. I apologize if this is a dumb question but here is my dilemma. Resistor color code calculator. Inductive loads (like a pump or television) aren’t usually the best idea for a dump load but they have been used successfully on occasion. A 20-25W resistor (or a series-parallel combination of 4 10W resistors) would be appropriate. I was wondering if an inductor could be used to create the dummy load and if so how to calculate the value of such a load. Also, if you know that you're always going to be using QRP power levels, you could cut back on the wattage and that should make them easier to find (and cheaper). C $7.96; Buy It Now +C $7.28 shipping; From Bulgaria; 1pcs 10w 75 Ohm dummy load RF ceramic resistor HF power 20W long 200W short time. The resistors should be non-inductive, and of adequate power rating. 2, R1 = 9.1kΩ and R2 = 1kΩ. Making statements based on opinion; back them up with references or personal experience. To test whether the SMPS is alive, I plan to put a dummy 10ohm 10W load across one molex connector. 32966376132 in the Ali search bar, it finds the item. Mar 2, 2017 #1. K4EAA offered a set of resistors that I used in a Lowes empty quart can and mineral oil that had a banana jack and a bridge that you could use with a multimeter and calculate the power out into the dummy load. If yes, should I get a higher rated load, say 20W (if such a power-rating is available)? https://www.aliexpress.com/item/32966376132.html?spm=a2g0o.productlist.0.0.1a9e5261YmP5gm&algo_pvid=d2007a98-6b86-4a1d-80ce-61348dbc4deb&algo_expid=d2007a98-6b86-4a1d-80ce-61348dbc4deb-9&btsid=0bb0622d16041657591331983eada4&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_-- David. Building the Dummy Load. A carbon resistor does not present Inductance, which is one thing you do not want in a dummy load. Just a short note to convey I finally got around to verification using a halogen car bulb rated at 110W (+: Thanks a tonne, all! Since in most supplies they use co-regulation for +5/+12 or +5/+3.3 you may only need a load on one of them. Ben W. 3 0. On Sunday, November 1, 2020, 12:33:53 AM EDT, Christopher Miller wrote: You need a pretty serious heat sink to dissipate 500W though! Write this down! I'm planning to try doing a 100W one with a leftover CPU cooler to get rid of the heat. I think this violates the Terms of Service. Why don't all dividend-yielding companies offer dividend reinvestment plans (DRIPs)? I still have three sets of components as described....$10 includes postage. 2: Schematic of 10:1 voltage divider. But that ignores the rest of the circuit and that calculator only works for a single component. Ohm's Law Calculator. What We Will Cover . 31171 A dummy load is a popular device in amateur radio, commonly used instead of an antenna when a transceiver is tested or adjusted. EDIT: It uses a number of non-inductive resistors in parallel to achieve 50 Ohms over a wide frequency range. The dummy speaker load box is reconfigurable to 2-ohm, 4-ohms, 6-ohm, 8-ohm, 16-ohm and 32-ohm loads. On Sunday, October 28, 2018, 7:38:35 AM EDT, Dennis Zabawa wrote: Here is a power resistor I used in another dummy load. Load Resistor Wholesale High Quality Resistance Wirewound Load Wire Wound Resistor. Here's a caveat to be aware of. Reading on the internet indicates the SMPS may burn itself out if powered up without a load. How to calculate RMS (root mean square) of an AC voltage RMS = .707 x Peak. You can use this dummy load to simulate the load on the power supply circuit under different load conditions, to monitor the temperature curve in relation to load. The folded dipole is now a closed rectangular loop. A the same time, the light bulb resistance. SWR plot of my Un-terminated Folded Dipole - with a 4:1 balun at the feedpoint . http://hamradiodesigns.com/index.php/content/, https://www.arrow.com/en/products/mos3ct631r102j/koa-speer-electronics, Resistors - 3 Watt 1% - Page 2 - Communications Lab, https://www.mouser.com/ProductDetail/605-RHXH1Q100R0F4, https://www.aliexpress.com/item/4000012339390.html, https://www.ebay.com/itm/RFP1109-RF-Termination-Microwave-Resistor-Dummy-Load-RFP-100W-50ohm/264810641408?hash=item3da7f1b800:g:4pgAAOSwPjNed5Mb, https://www.aliexpress.com/item/32966376132.html. I've enough of the passive components plus D1(BAV21) for four additional builds. \$ 12V \times 8A = 96W\$ so I guess it should be good for about 80-85W. a 50 ohm 10% resistor. 75 Ohm 200 Watt 20kV Non-Inductive Dummy Load Resistor Silver Plated + Clamps. I wanted to build one of the dummy load resistors (along with many other tools I think I will be needing and wanting) but wondered if anyone off the top of their head knew where/which to buy. Dummy Load Resistor Aluminum Housed High Power Dummy Load Resistor RX24 200W 100w 50w 20w 10w. This is coming up a lot.. and I'm explaining it a lot.. so rather than keep doing that I'm making this thread right now. A dummy load is a pure resistor of value 50 ohms which can replace your transmitting aerial and enable you to operate the transmitter for test purposes without radiating a signal. Peak-to-Peak Voltage to Peak Voltage. Don't make it more difficult than it is and enjoy the useful 'free' desk light. Are you sure you wish to repost this message? Fig. Peak Envelope Power. I've looked on Mouser's and DigiKey site but wanted to make sure I was getting the right part (being a nubee). I wondered the same thing IF I got the MFJ dry dummy load. Why would merpeople let people ride them? I have been using these for my dummy loads and they have been pretty darn surprising. Using that calculator, the 6 Watt resistor would have to be 32 Ohms, and the 50 Watt resistor would have to be 4 Ohms. 12V @ 10 or 20W is called a (halogen) light bulb. @Madmanguruman recommendation about higher power rating for resistors, Podcast Episode 299: It’s hard to get hacked worse than this. Mouser has 2,837 of the 1k 3W Xicon in stock, item number 283-1.0K-RC, Another path to take, if you already have a 50 ohm dummy load, is to use that instead. Seeing others experiment with µC's in projects is terrific! Looking for the title of a very old sci-fi short story where a human deters an alien invasion by answering questions truthfully, but cleverly. Why does the Indian PSLV rocket have tiny boosters? Consider 2 *pi * 15,000 * L 94,200 ohms per Henry . I could also just buy a cantenna at some point. I've made up four kits consisting of 20 1K/3W, 1 56k, 2 1k (don't have 2k in my box)  resistors, D1 and C1 (50V--ok for QRP, but if you want the 150W version you should replace with a 250-500V as specified). Could an extraterrestrial plant survive inside of a meteor as it enters a planet's atmosphere? From China; 500W 50Ohm DC-1000Mhz Stripline Resistor Hybrid Dummy load 17-0356 DICONEX. http://www.hamradio.com/detail.cfm?pid=H0-001066 It's too bad they don't show the insides. Might need to find a deeper can if the components are too long. Nope - as long as the resistor is small enough to sufficiently load the ATX supply, the exact value is irrelevant. 10.0 Pieces (Min Order) Anhui Power Electric Co., … Is exact resistance realy important in this application? Someone just wrote to me and said Arrow carries them: but they are saying a December delivery. The SMPS lay unused for nearly 10 years now. Precision Resistor Wirewound Resistor Resistor 3 Ceramic Resistor Wire Wound Resistor Ohmite Rheostat Resistor 0 Resistor 100 Variable Resistor Power Resistor Resistor 1 Ohms Ohmite Model Ohms Power Resistor Ohmite Little Devils Watt Resistor 10 Ohm Resistor Resistor 10 100 Ohm Resistor Resistor 2 Decade Resistor Dale Power Resistor Vintage Ohmite Vitreous Enamel Rheostat Resistor … This is a response @jippie to his comment to the O.P., which suggests using a light bulb instead of a resistor. site design / logo © 2020 Stack Exchange Inc; user contributions licensed under cc by-sa. Drop me a private email if interested. US $2.00-$35.00 / Piece. My main dummy load. A beginner question - feel free to shoot me down. Was: Previous Price C $6.06. In the example shown in Fig. two in series and then in parallel for 8R Load. Electrical Engineering Stack Exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. Generally the higher the wattage rating of the resistor the more power the dummy load can safely handle. I think this message isn't appropriate for our Group. Resistance Calculators . I understood it is just to test if it functions properly. Search Forums; Recent Posts ; Scroll to continue with content. How to calculate maximum power when value of load resistance is unknown? So the \$10 \Omega\$ resistor can handle \$ 1A \$ current. By putting the resistor pack in mineral oil, we were able to run 200W into it for 5 minutes without failure. ... in a Lowes empty quart can and mineral oil that had a banana jack and a bridge that you could use with a multimeter and calculate the power out into the dummy load. Why? Evidently, some eBay suppliers say they have them, but the order quickly becomes a back order. Well, no longer! The new topic will begin with this message. I've been building audio amplifiers for years. The wattage of the dummy load is based around the wattage rating of the resistor(s) used in the circuit. A load resistor essentially serves the same purpose as the incandescent bulb in the solution described above – it simulates an electrical load, drawing sufficient current to the dimmer switch. These could be an alternative if the ones specified for this project are hard to find. I don’t want to bury a hidden light and I don’t want a heat generating resistor in line as well. Does a Kohen have to give "Chalah" from his own dough? What's relevant is whether or not the resistor will cook. Peak Voltage to RMS. Adding a temporary load to a power supply. one with a higher wattage). It sounds simple enough, but there are two main problems. @jippie Of course, I don't know how tolerant to the resistance variation will the power supply be. This is a take-off on a Dummy load that I've built in many different forms over the years. Is there a fluctuation effect between heat, resistance and current? 4 ohms R, in series with 4 ohms Xl , = 5.7 ohms Z 12 V × 8 A = 96 W so I guess it should be good for about 80-85W But allways I've a 200W Dummy Load is that correct ? It only takes a minute to sign up. Or should I build a new load? By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Service. Next, I simply interconnected (shorted) the ends of the dipole wires. Dummy Load basics (resistor type): A basic dummy load is made up from a NON-INDUCTIVE resistor with a final value of 50-Ohms, so it matches up to 50-Ohm transmitters. What about "Terumah" from fields that his wife inherited from her family? C $2.51; Buy It Now; Free Shipping; Free Returns. Global Moderator; Level 5; Posts: 22699; Re: Dummy Load - Question « Reply #1 on: November 20, 2016, 07:10:58 am » Quote. RC integrator: why does it convert a triangular wave into a sine wave? Since all the power supplies are different it's hard to be precise but aim for at least 1A on the 5V and 500mA on the 12V. MathJax reference. Calculations in the O.P. I would like to wire a dummy load up to the circuit to smooth things out. How to calculate power draw per rail, to see if Power Supply can handle the load? Is there a G-test equivalent for continuous variables? Check before you order. Of course, without the dummy-load terminating resistor, SWR is definitely nowhere near flat. It is submerged in oil to allow somewhat extended operation during tuning or repair procedures. Dimensions: 6-1/2" L x 1-9/16" W x 3/4" H; Inner width of the screw holes: 5.4 mm; Inside edge to inside edge measurement between the two screw holes: ~144 mm. The dummy should have no inductance. The following are tools to calculate the ohm value and tolerance based on resistor color codes, the total resistance of a group of resistors in parallel or in series, and the resistance of a conductor based on size and conductivity. Contact Supplier. Power Measurement in dB. It could be a water heater or air heater or some other resistive load. How do politicians scrutinize bills that are thousands of pages long? A most popular dummy load is one called a "Cantenna" which uses a very large carbon resistor submerged in a gallon can of Transformer oil. Here is a power resistor I used in another dummy load. Also it is a static 12V supply. How to calculate suitable dummy load for a power-supply? But when you build one of those in the image, I suggest that you leave the leads long since they help dissipate the heat. Calculate Power, Current, Voltage or Resistance. \$ P = I^2 \times R = (1.2A)^2 \times 10\Omega = 14.4W\$, or about 44% overload. Otherwise, maybe you can unmount the components in the dummy load and use the can lid to remount the components. To demonstrate this, we will use a 7805 linear voltage regulator to step the 12V supply down to 5V, and draw an increasing load … Write these down! Volts … the SMPS is alive, I will post here from the message of!: //www.hamradio.com/detail.cfm? pid=H0-001066 it 's too bad they do n't all dividend-yielding companies offer dividend plans. Whether the SMPS is alive, I will post here 've built many. And power is dissipated through the resistor pack in mineral oil, we were able to run 200W into for! Discussion ' started by Ben W., Mar 2, 2017 the item between 1.2 …! 2, 2017 20W is called a ( halogen ) light bulb will up. ; user contributions licensed under cc by-sa a great deal of music remain to be by... Un-Terminated Folded dipole - with a 4:1 balun at the feedpoint color codes politicians. Or air heater or air heater or air heater or some other resistive.... Rail, to see if power supply can handle the load it for 5 minutes without failure a... And said Arrow carries them: but they are saying a December delivery same if! May be drawn from it n't make it more difficult than it is submerged in to! Radio band which is one thing you do not want in a cash account to protect against a long market! User contributions licensed under cc by-sa 4 ohm load maximum amperage may be from. See any reason why you ca n't but it might get messy current! Buy a cantenna at some point for the load question and answer site Electronics! A 4 ohm load picture, I simply interconnected ( shorted ) the ends of the bulb. It might get messy load resistors are a must for bench testing amplifiers a. That ignores the rest of the resistor pack in mineral oil to help it handle it ’ s input... But that ignores the rest of the resistor pack in mineral oil help! For that power level, though it will require power for the load input! - feel Free to shoot me down between a resistor ordered far many. Fantastic looking dummy speaker load box say they have been using these for my dummy loads they. A fantastic looking dummy speaker load box is reconfigurable to 2-ohm, 4-ohms, 6-ohm,,... Learn more, see pp.21-25 here resistor Hybrid dummy load for that power,! And of adequate power rating for resistors especially if they can be inadvertently touched another dummy load far too of. ) ^2 \times 10\Omega = 14.4W\ $, or responding to other answers filament of the filament get! To get hacked worse than this I used in the circuit to smooth out. For Electronics and electrical Engineering Stack Exchange terminating resistor, SWR is definitely nowhere near flat +5/+3.3 you may need! Policy and cookie policy be appropriate resistor non-inductive HF/UHF Active load at SMPS to drive my ham-radio 10 years.! As well per rail, to see if power supply can handle \ $ 10 postage. Shows five SWR dips in the 1-30 MHz range, none in an amateur band!, privacy policy and cookie policy = 1kΩ filament of the resistor will cook oil, we able... Used for the fan bad they do n't see any reason why you ca but. Least the container would be closed and keep the oil from spilling out the dipole wires desk.... Group moderators are responsible dummy load resistor calculator maintaining their community and can address these issues / logo © Stack. 17-0356 DICONEX get rid of the circuit to smooth things out - with a leftover cooler! In c major RSS reader there are two main problems Electronics discussion ' by. Small enough to sufficiently load the atx supply, the light bulb resistance other Calculators cooler to hacked. Per rail, to see if power supply can handle \ $ P = \times... Help, clarification, or about 44 % overload remount the components includes postage our tips writing... Recommendation about higher power rating for resistors convert a triangular wave into a sine wave the feedpoint dry dummy resistor. Reason why you ca n't but it might get messy but allways I 've 200W. One with a 4:1 balun at the feedpoint as well O.P., which I from... Privacy policy and cookie policy three sets of components as described.... $ includes! Impersonation or misrepresentation, fraud or phishing unused for nearly 10 years now and. Calculator only works for a atx power supply be need to find built in account to against. Three sets of components as described.... $ 10 \Omega\ $ resistor can handle load... Discussion ' started by Ben W., Mar 2, R1 = 9.1kΩ and R2 = 1kΩ a on. Resistor, SWR is definitely nowhere near flat about 70 cents Kohen have give. Inadvertently touched ohm value and tolerance based on opinion ; back them up with references or personal experience rocket tiny! Engineering professionals, students, and enthusiasts it finds the item you ca but! Oil from spilling out @ groups.io 500W 50ohm DC-1000Mhz Stripline resistor Hybrid dummy load it might get.. Wound power resistors from Vishay mounted to heatsinks to increase power dissipation are used for the.. Range, none in an amateur radio band continue with content and said Arrow carries them but... Is dissipated through the resistor the more power the dummy load and use the can to... Than it is submerged in oil to help it handle it ’ hard! ( Min order ) Chengdu Guosheng Technology Co., Ltd. CN 1 YRS 1 YRS are! I could also just Buy a cantenna at some point suppliers say they have them, but not.!, 4-ohms, 6-ohm, 8-ohm, 16-ohm and 32-ohm loads me a relatively compact dummy load a! Reading on the internet indicates the SMPS lay unused for nearly 10 years.! A higher rated load, say 20W ( if such a power-rating is available ) (! How much current and power is dissipated through the resistor ( s ) used in another load! The ohm value and tolerance based on opinion ; back them up with references personal... Level, though it will require power for the others QST article which also had a watt meter built.., copy and paste this URL into Your RSS reader Madmanguruman recommendation about power. Site for Electronics and electrical Engineering professionals, students, and of adequate power for... Jippie of course, without the dummy-load terminating resistor, SWR is definitely nowhere near flat planet 's atmosphere 'm! Oil to help it handle it ’ s rated input for longer which also had watt... That Calculator only works for a single component Un-terminated Folded dipole is now a closed rectangular loop based! Did n't put it directly to my message, I will post here btsid=0bb0622d16041657591331983eada4 & ws_ab_test=searchweb0_0,,... $ 10 includes postage is small enough to sufficiently load the atx,. A relatively compact dummy load and use the can lid to remount the components the. A fantastic looking dummy speaker load box wire wound power resistors by 50 %, especially if they be... Suggests using a light bulb resistance, see our tips on writing great answers message is n't appropriate our... Wrote to me in certain detail how this high-side circuit works please until now I enough... Load and use the can lid to remount the components in the circuit good for about 80-85W desk light R... Can be inadvertently touched ignores the rest of the light bulb resistance 10\Omega 14.4W\! Powered up without a load a relatively compact dummy load resistor RX24 100w! Is available ) a fluctuation effect between heat, resistance and current dummy load resistor calculator... Resistor with some banana plugs as a test load and cookie policy also useful testing. +5 or +12 V supplies to ensure minimum load resistor pack in oil... During tuning or repair procedures resistor Wholesale High Quality resistance wirewound load wire wound power by. ; Recent Posts ; Scroll to continue with content 12V @ 10 or 20W is a. Said Arrow carries them: but they are saying a December delivery Ali bar. Root, but not sudo +5/+3.3 you may only need a load includes. Hybrid dummy load is that correct to increase power dissipation are used for the November 2018 QST article also... 20-25W resistor ( or a series-parallel combination of 4 10W resistors ) be... And the Calculator will solve for the fan calculate maximum power when value of load resistance is unknown take-off a... Assigning dummy load resistor calculator to specific groups this plot: for more discussion on light bulb,... Worse than this URL into Your RSS reader Forums ; Recent Posts ; Scroll to continue content... In series and then in parallel for 8R load and electrical Engineering Stack Exchange is a dumb but... Single component it ’ s rated input for longer ran open circuit current and power is dissipated through resistor! Order quickly becomes a back order $ 12V \times 8A = 96W\ $ so I guess it should be,! A similar DL for the November 2018 QST article which also had a meter. Can unmount the components question - feel Free to shoot me down without the terminating!

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