computer power supply

[rev_psilocybe]

What is the possibility of using a 4-500 watt regulated computer (ATX) power supply for some of these 12VDC chip amps? Is it possible? Is the line noise that horrible?

[neutron7]

if you used some extra capacitors near the chip, it should be good enough for TDA type chips. dont expect too much from them though.

[imix500]

also remember that you will probably have to load the primary (5v) rail to keep the supply happy.

[rev_psilocybe]

thanks for the feedback, much appreciated!

Now that I know it's possible I'll throw something together and what happens. I'm sure I can keep that 5V happy with a few LEDS.

I've used one previously to run a 100watt car amp bridged to drive a 12" horn sub. Little noisy on startup but worked flawlessly every gig. And that was a PSU with those damn bad Caps that got into everything a few years back.


thanks again!

[neutron7]

you could power quite a few with this

http://www.pcpowercooling.com/about/whatnew_850_ETX.htm

" Four +12V rails @ 17A ea. (12V1-V4=54A/62A pk.) "

[rev_psilocybe]

one more question! Woud it be possible to simmply connect the +12, +5, -5, -12, and GRND of 2 PSUs together to get 24v?

[Giaime]

Originally posted by rev_psilocybe
one more question! Woud it be possible to simmply connect the +12, +5, -5, -12, and GRND of 2 PSUs together to get 24v?

Mmmmm... I think you're looking for smoke

[indoubt]

I've used a PC PSU to power an old carradio. The PSU is modified with a 10.000uF cap, a small bypass cap and a 17Watt resistor on the 5V to keep the supply from shutting down.

It works, it even works reasonable well after adding the capacitance but I don't think it will be as good as a regular supply. It remains a little noisy alhough the fan drops in speed after a minute or so because the supply is operating far from max.

Don't connect the other wires to get 24 Volt, I think they have a common ground ro zero and then you shortcut the thing instantaniously. different PSU might have different topologies though.

[dnsey]

I'm currently using a computer PSU to provide + & - 12V supplies for a commercial (Fender) mixer. No dummy load on the PSU, and very little supply filtering in the mixer. Perfectly reliable, and no audible noise through a 200W a side amp.

[rev_psilocybe]

Originally posted by dnsey
I'm currently using a computer PSU to provide + & - 12V supplies for a commercial (Fender) mixer. No dummy load on the PSU, and very little supply filtering in the mixer. Perfectly reliable, and no audible noise through a 200W a side amp.

Did you modify your PSU at all? What rating? 250 -500w?

I never had to dummy load the 5v on mine either, just short the remote turn on wire to a ground. I'm getting the feeling this 5v dummy stuff is only for AT power supplys...