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View Full Version : DIY bench voltage Regulator.


swatson144
08-22-2006, 06:19 PM
I find myself needing a good regulated LV power supply fairly often, but not often enough to buy one.

I had come across the very nice little Ti PTN78020W switching voltage regulator module, but by the time you add components to make it a BEC you'd have one the size of a 60A ESC. So they sat around some.

The other day I was wanting to test the alarm cut in voltages of some home made lipo alarms and was trying to figure out regulate the voltage down so I could see what was happening with them. I just stuck the module together with a handfull of components IAW the info sheet and in place of the set resistor I put a 100K 10 turn pot. I can now get a very accurate voltage between 3 volts and 12V @ 6A.

It's all mounted on perf board and covered in heat shrink. Works great for a proto.

I'll probably get a little fancier with the next one and put it in a small cabinet and add a selector switch for 5V, 6V, 12v, and variable. Probably mount up a couple 4$ harbor fright DVMs like the one pictured one showing 0-20V and the other 0-10A.

It's setup to use a JST connector for 0-30V dc in (but my caps are 24v which is no problem because it's likely to run on a 12V wall wart, charging stations PS etc). I'll switch to deans sometime.

Pretty handy for 20$

thanhTran
08-25-2006, 01:27 AM
Looks great Steve. Care to share the circuit? I didn't find a need for a high current one so I just used a small LM317. It works well but can't provide much current :).

Thanks

thanh

swatson144
08-25-2006, 03:19 AM
The circuit consists of 2 caps a resistor and the module. :D .

You'll find the specs sheet here http://focus.ti.com/docs/prod/folders/print/ptn78020w.html along with the place to request a free sample. :lol:

I haven't found any place you can actually buy the module. :oops:

I love the thing! I have never before owned my own PS that I can dial down to within .01v easily. Sure makes testing homemade lipo alarms easy. Since you are in semi production of alarms you could easily set it up with a rotary switch for various Go no go voltages, as no other components need to be changed to change the voltage except the resistor.

Steve