# 12V converter hacking from a 120VAC 5A(or more) power supply

**URL:** <https://community.electricforum.com/t/12v-converter-hacking-from-a-120vac-5a-or-more-power-supply/17681>\
**Category:** GEM Forum\
**Created:** [December 12, 2019, 8:50pm UTC](https://community.electricforum.com/t/12v-converter-hacking-from-a-120vac-5a-or-more-power-supply/17681 "2019-12-12T20:50:26Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![dougl](https://avatars.discourse-cdn.com/v4/letter/d/b19c9b/32.png) [@dougl](https://community.electricforum.com/u/dougl)\
**Post date:** [December 12, 2019, 8:50pm UTC](https://community.electricforum.com/t/12v-converter-hacking-from-a-120vac-5a-or-more-power-supply/17681/1 "2019-12-12T20:50:26Z")

</div>

Has anyone tried something like this? If you don’t know, 120VAC(RMS) is 170V peak voltage. The input can easily handle the battery voltages we see, 75-90V at the input. Most power supplies will convert the AC is rectified DC, filter it a bit and then switch it at a higher frequency before stepping down from there.

The only thing I see happening which would give me something to look at would be the fact that all the input is basically using only two of the 4 diode in the bridge rectifier but then again, the other two are always just blocking anyways so not too big a deal. The other thing is that the lower input battery voltage would therefore pull higher current for the same output current. But if you want 3A then get a 5A setup and you’re covered.

Might be handy for any extra loads people might add like holiday lighting, music, etc and way less money than a special purpose converter.

[https://zenid10.wordpress.com/category/4-how-to-guide/4-2-72v-upgrade/4-2-2-building-a-72v-dc-converter/](https://zenid10.wordpress.com/category/4-how-to-guide/4-2-72v-upgrade/4-2-2-building-a-72v-dc-converter/)