Can you use ATX power supplies with the ArcadeShop MCR adapter?

keithsarcade

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Can you use ATX power supplies with the ArcadeShop MCR adapter?

I have one new one for an arcade game, and another from an old computer with a pushbutton on/off switch, both 200w, both have all the proper voltages needed. I am wondering if they can be used for these adapters, or if you have to use a screw terminal style swithing power supply. Can anyone shed some light for me?

Thanks in advance.
 

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I'm not sure what exactly what the MCR adapter is, but... 99% of ATX supplies are switchers that require a minimum load on the 5V line. If your load isn't big enough, you may get severe undervoltage that won't adjust out, or the supply may just refuse to stay on for more than a second or so. You can work around this by putting load resistors (big ceraic resistors) on the 5V line, but they produce significant heat, so keep them away from anything expensive. Btw, the bigger the PSU's rating, the bigger the minimum load needs to be, so small is probably a good thing unless you're powering a power-hungry game.

If you're gonna do this, cut PS-ON (usually the green wire in the 20-pin connector) and short it to DC ground (generally, any black wire coming out of the PSU). PS-ON is how the computer tells the power supply to turn on; shorting it to ground makes it "always on". (You could alternately put in a switch if you want to turn game logic on/off without powering off the whole cabinet.) If the power supply only turns on for a second, or doesn't respond at all, it may be bad, but it's more likely your load just isn't big enough.
 
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yes, but most atx power supplies don't have adjustable voltages. With the voltage drops mcrs are known for you may very well end up with a +5 that's too low for the pcb to boot. The pcb has plenty of load for the atx power supply.
 
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