Building a Resistor Dummy Load Box - Page 1
Forum section: electronics / beginners

author: DW1961
author_rank: Frequent Contributor
timestamp: November 13, 2021, 09:53:48 pm
content: I just bought some resistors and put them on a heat sink to load a power supply. It's works fine, but now I wan't to build a box and fan system, and I don't like the resistors I have.Currently I have 4 100W 6R resistors. I'm running them in parallel and series to get 150W. I wanted to run 4 for better heat control. Now I want to build a dummy load box with more wattage options.The resistors I have now are the two hole design, with both holes on the same side, and they don't screw down as flat as I would like. I sanded them down and got them as flat as I could, but the 2 hole on one side design, imo, is a bad design (except it takes up a little less space). I found the same type with 4 holes so I'm in the process of trying to figure out which combination of Ohms would be best before buying the 4 hole resistors.https://www.amazon.com/gp/product/B08XH5TP5Y/ref=crt_ewc_title_oth_3?ie=UTF8&smid=A14FP9XIRL6C1F&th=1If possible, I'd like to keep the number of resistors to 4 and get as close as possible to 10A/30V/300W out of them. That would be the very top end of what I would need. What would be the most efficient combination or resistors for that task? I want to keep this as simple as possible.I'm not opposed to using SMD resistors, if that would be possible.https://www.amazon.com/Hechengdianzi-100w-Dummy-Load-Resistor/dp/B08CX9PBFV/ref=sr_1_30?crid=28R8ZMT4F48S0&keywords=dummy+load&qid=1636840512&s=industrial&sprefix=dummy+load%2Cindustrial%2C240&sr=1-30

author: Gyro
author_rank: Super Contributor
timestamp: November 13, 2021, 10:55:47 pm
content: Wouldn't it be better to keep this stuff together? It would certainly save on keeping track of the answers you've already got and the frustration of answer duplication...https://www.eevblog.com/forum/beginners/dummy-load-for-bench-power-supply-resistors/https://www.eevblog.com/forum/beginners/resistors-parallel-vs-series-best-heat-dissapation/

author: DW1961
author_rank: Frequent Contributor
timestamp: November 15, 2021, 06:18:39 am
content: Quote from: Gyro on November 13, 2021, 10:55:47 pmYes, in some form. But the other two threads were very specific, and most people comment after reading the original post. One was for series vs parallel and One for building a dummy load for a 150 watt power supply.This one is for building a box with specific R resistors in the most efficient way to get the most power combinations out of them. So, what do you suggest to combine all three threads without confusing each threads specific purpose and dialogue?

author: Gyro
author_rank: Super Contributor
timestamp: November 15, 2021, 05:36:52 pm
content: I'd go for the carrying on in the 'resistors-parallel-vs-series-best-heat-dissapation' thread then - that seems pretty much the same thing.

author: DW1961
author_rank: Frequent Contributor
timestamp: November 16, 2021, 05:35:24 am
content: Quote from: Gyro on November 15, 2021, 05:36:52 pmOK, how do I delete this entire thread?

author: tkamiya
author_rank: Super Contributor
timestamp: November 16, 2021, 06:53:19 am
content: There is a "report a post" button on bottom right. Report yourself and ask moderator to lock it for you. It won't be deleted but it will prevent further progress.

author: beanflying
author_rank: Super Contributor
timestamp: November 16, 2021, 06:58:39 am
content: You can also merge threads and if the posts here fall after those in the other thread then they will just drop in sequence.