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?
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.
also remember that you will probably have to load the primary (5v) rail to keep the supply happy.
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!
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!
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.) "
http://www.pcpowercooling.com/about/whatnew_850_ETX.htm
" Four +12V rails @ 17A ea. (12V1-V4=54A/62A pk.) "
one more question! Woud it be possible to simmply connect the +12, +5, -5, -12, and GRND of 2 PSUs together to get 24v?
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.
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.
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.
dnsey said:
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...
It's an old 150W AT supply with no mods at all (apart from removing the unwanted output wires). I've used another to power an LCD display and QH lamp (+12v) without any problem.
Computer supplies have the great advantage when experimenting of foldback limiting and shutdown if shorted or overloaded 😉
Computers PSUs are great imo. The only limit is the low voltage (you cant draw much AMPs between the -5 <-> 12v).
I have it to power my car amplifier driving two speakers with 12".
Its a cheap one but still its capable of deliver 7-8 amps constant (i have tested with a peltier element).
And as someone mentioned, you can really mess with them - they hardly brake.
Its even cheaper then bying a trafo with that rating, and on modern ones the ripple is very low.
So, use it!
I have it to power my car amplifier driving two speakers with 12".
Its a cheap one but still its capable of deliver 7-8 amps constant (i have tested with a peltier element).
And as someone mentioned, you can really mess with them - they hardly brake.
Its even cheaper then bying a trafo with that rating, and on modern ones the ripple is very low.
So, use it!
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