Computer Science Canada Need plans for variable power supply |
| Author: | ecookman [ Tue Oct 09, 2012 8:16 pm ] |
| Post subject: | Need plans for variable power supply |
Anyone know of a good set of plans where I can make a variable 0 to +12V bench power supply. Variable not fixed outs please, just a single terminal. |
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| Author: | chrisbrown [ Wed Oct 10, 2012 5:22 pm ] |
| Post subject: | Re: Need plans for variable power supply |
Linear regulators tend to work well without much fuss but minimum voltage is more like 1.3V and the maximum is about 2V less than the input voltage. If you don't need less than 1.3V and can supply at least 14V to the device, take a look at these: <a href="http://www.ee.buffalo.edu/courses/elab/LM117.pdf">LM317 (1.5A)</a>, <a href="http://www.onsemi.com/pub_link/Collateral/LM350-D.PDF">LM350 (3A)</a>, <a href="http://cxem.net/doc/pitanie/LM138.pdf">LM338 (5A)</a>. I used a few of each in my own supply, I can post the schematic if you're interested. Switching regulators are more efficient but they don't come in a convenient three-pin package and variable ones are very difficult to design. If you're feeling lucky, there's <a href="http://www.youtube.com/watch?v=mK_rIs7uFlo">this option</a>, but don't hold me responsible for any unintended results. |
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| Author: | ecookman [ Fri Oct 12, 2012 6:20 pm ] |
| Post subject: | RE:Need plans for variable power supply |
Hm, I was doing some math, it appears that the regulators will give off a retarded amount of heat if i am drawing a small voltage.... I think I'm going to just use a 12V rail from a PSU and build an amp circuit so I can bump it to 24. Know of a transistors that will do this well, or something similar? thanks for the help! |
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