Is SMPS only made to be used with PC?

[channabasanna]

Hi All,

I have 2 SMPS as extra with me now. I love playing with DC motors, and doing stuffs with that, So i just tried using the spare SMPS as they provide 12V output, when i tried by connecting the DC motor to the Molex correctly, when switched on it did not work, later when my brother's friend doing his final year Electronics Engg project took it to use it for charging his battery. Yet it didn work.

But when we connect the SMPS to the motherboard and PC then it works fine. What may be the reason.

Is SMPS only made to be used with PC.

[pimpom]

The standard computer SMPS is designed specifically for use with a PC, but you can also use it for other things if you know how to use it.

One thing you have to know is that when you simply connect the SMPS to tha mains power, it gives out only a low-power standby output. To turn it on fully, it has to be triggered by the motherboard. This is what happens when you push the power button on your cabinet.

There's a way to turn it on manually without connecting it to a motherboard. Look at the 20-pin connector (24 pins in newer SMPSes), identify the green wire in the middle of the connector. That's the trigger line. There's a black wire right next to it.

Now use a short piece of wire to connect the green wire to the black wire. The SPMS will now turn on fully. You can fit the green-to-black connection before you connect the SMPS to the mains and leave it connected.

The above descriptions are for a standard ATX SMPS. Older AT SMPSes do not need the triggering signal. SMPSes in some branded computers may use a non-standard connection.

A word of caution: Be careful you don't exceed the SMPS ratings. DO NOT attempt to charge a battery directly with any of the outputs.