Power supply ?'s

[aj6500]

I have an ATX power supply that I'm going to use to power a 12v amplifier.  I have a couple ?'s for those who know more about them than I do.  I'm experimenting w/a 200w, and I have a 500W on order to actually power the amp.

I have 2 4 wire harnesses exiting the supply, 1 red, 1 yellow, and 2 blacks.  Correct me if I'm wrong, red will be +12v, black will be ground, what is yellow?

I also have 1 large harness that plugged into the motherboard w/20 misc. colored wires.  I'm guessing that some of these are also DC out, but I'm guessing they are of lower voltage and of no use to me for this project.  Will any of these be a 12v out?  I need to gather all possible 12v sources as they will all be connected to the 12v input on the amp to increase the combined wire size to the amp.

I would like my PC to turn on the 2nd power supply when it turns on.  I plan to run a jumper from the remote switch on the back of my cab that turns on the pc to the power supply.  The PC and the one I pulled the PS from use momentary buttons for power.  How do I find which wire to connect to on the main harness to make this work?

[NAH]

I have 2 4 wire harnesses exiting the supply, 1 red, 1 yellow, and 2 blacks.  Correct me if I'm wrong, red will be +12v, black will be ground, what is yellow?


on the two molex connectors, red is +5 V, both blacks are ground, and yellow is +12 V

[paigeoliver]

I have an ATX power supply that I'm going to use to power a 12v amplifier.  I have a couple ?'s for those who know more about them than I do.  I'm experimenting w/a 200w, and I have a 500W on order to actually power the amp.

You may very well fry the power supply for operating without a load on the +5 circuit. Get SOMETHING that draws +5 volts as well.

[BobA]

This link has info re the ATX type power plug that you will find on most newer PS.  It should answer your question about voltages and the power control signal.

http://www.duxcw.com/faq/ps/ps4.htm

If you are not going to be using the 5V from the PS then the minimum 5V load should be connected.  If it requires 1A of load to stablize the 5V then a 5 ohm power resistor will provide a 1A load to be safe get a 10W resistor.  The value available will probably be 4.7 ohms if I remember my resistor values correctly.

Good Luck

BobA

[aj6500]

Ok, if I strip the motherboard out of my old computer, strip CPU/memory... from it,  and plug the main harness into it, but use the 12v outputs from the power supply to run the amp, will that keep the power supply stable and still provide the voltage I need?  

[BobA]

A stripped MB may give enough load but the Power On button would not work if the MB did not work.   A power resistor on the 5V line is probably a simpler $1 setup.

BobA

[aj6500]

Ok, which 5v line are you referring to?  The one on the output, or one on the main harness?  Why will the lack of load on the 5v line damage the PS?

Lastly can I run jumpers from the PC power supply to the amp power supply so both will turn on at the same time?

[BobA]

There is only one 5V source in most PS.  Lots of wires same regulator circuit.  Lack of a load may or may not damage a PS. Some PS will not turn on without some 5V load.  Check the PS name plate it will have a max current output for the 5V but may also have a lower current limit that must be met for the supply to operate properly.

Turning on the P Supplies at the same time depends on the type of PS.  Old AT PS can be turned on by just supplying AC power and leaving the switch on.   ATX power supplies need a power on signal that is usually from the MB via a momentary contact switch.  As per the link provided earlier an ATX supply can be turned on via the jumper mentioned on the referenced page. This will cause the PS to come on as soon as AC power is suppled and may cause damage if it is not properly loaded.  Your experience with using such a jumper is dependant on the requirements of the PS that you are using.   In other words you could possibly smoke the supply.

BobA


BobA

[aj6500]

What a pain in the butt this is getting to be.

I've been using a home receiver to run my speaker in the juke.  The problem is that since the receiver is mounted inside the cab, the volume and power button are not accessible.  I had an extra hole in the cab to get to the power button.

Since I can't get to the volume I was using the volume feature in VJ.  But to make it so I can listen at polite neighbor levels as well as it's a jukebox and I'm going to make the walls shake levels I had to have the volume on the receiver cranked, otherwise I could never get a loud volume.  

The downside to this is w/the volume cranked any kind of interference, voltage fluctuation... would be picked up through the cables and you'ld hear it.  Didn't bother me when the music was on, but between songs you could hear it.  I believe this is because the home receiver is designed to have a constant low level being supplied by the cd player or whatever, and volume control only through the receiver.

So I decided to switch to a car amp as they are more tolerant to line noise, and are made to have fluctuating levels on the input and should be more resistant to the problems I was having.  The only way to do that is to get a relatively high amp 12v supply to keep the amplifier running.  I could use the PC PS, but I don't think it would be a good idea.  So I decided to use an extra PS and rig it to work.  But I'm having second thoughts.

Anyway, I was out in my garage looking for some wiring and other goodies to work with and I found the remote for the home amp I was using.  I didn't even know I had the remote, the reveiver belonged to the wife --BINGO! Either that, or I was attempting to say "before" but it was too many letters to type-- we met, and got shoved into storage as my system was better.  So I decided I could re-install the home reciever and hack the remote so I could use the original juke control panel.

 I figured I could mount the LED next to the IR receiver and basically do a gamepad hack to the volume buttons.  But after I pulled the remote apart I found that it's a single-sided double layered board that is very hack unfriendly.  Sony sucks.  So I've decided to re-install the receiver, set the software volume conrol to 100%, and just shoot the remote through the hole in the side to power the receiver and adjust the volume.  I figure I can use the power supply when I build a mame machine.

Such a long route to get right back to where I was.  On the plus side while I have the internals out I'll rig my flashing neon tubes.  And as soon as my IPAC arrives I'll finish the control panel.

Thanks for all the help, next time I'll use the advice given I promise.