DIY powersupply

[TimRawson]

Curious, any DIY power supply kits? WOuld like to reuse a good car audio amp but the tricky, and expensive part, is to create a 12-14VDC from AC.

As an experiment, bought a lump of 10 new, obsolete (AT motherboard), computer power supplies. Rated to provide 6A on the 12V output. Planning to dismantle them , parallel the 12V outputs (combine current sources) to produce 6 x (number of units) amps needed. Will this work, theoretically should. The car audio amp has 40amp fuse. So, looking to put 8 together. Maybe just two to do a quick stablility test before I go gung-ho.

Would be an awefully cheap 12VDC supply - 5 bucks + time and effort. Of course would have to mount this stuff up, enclose it, put a fan on it. Probably throw it in my garage and set up some relay turn on.

[ThomasW]

This is NOT a good idea.

Amplifiers present a dynamic load with HUGE swings in voltage AND amperage. PC power supplies are not designed to supply this type of power. And trying to 'strap' multiple switching power supplies together is a bad idea. You run the risk of destroying the power supplies, the amp and maybe burning down the garage just in time for the holidays.

Sell the amp and power supplies buy something appropriate for home use.

[TimRawson]

Thanks... wasn't worried about destroying powersupplies, but of course don't want to create a hazard. Just wish there was a way to create a 12vdc cheaply - curious what stores use to run there displays. But of source that is commercial grade and very pricey for home use. OH well - guess I'll hold onto the amp for car use someday.

[taz13]

Deep cycle batteries and charger, anyways that is what I use at my cabin( it is off grid). Stereo and HT are all 12Vdc and works great, even when driving 8 ohm speakers.

[thylantyr]

Since you bought the supplies and are not worried,
then pick the ones that have the closest measured 12v output and use a high current diode on each output (if it doesn't have one internally) to parallel them.

ps1 output --> diode --> +12v out
ps2 output --> diode --> +12v out
ps3 output --> diode --> +12v out

Connect all the +12v out's together.

This isolates each power supply from one another, but
you get current sharing when they start to load down and
the voltages equalize.