Info on Power Supplies?

[str8jakit]

There seems to be a lot of power supply related discussion lately, and I thought I would take the opportunity to try and clear up something that I am not sure about.

What is the difference between an AT and ATX power supply (besides the mainboard connectors)?

In another topic, I wrote that I had to replace the power supply on my kids' computer. When I went to Best Buy, they had a 250W AT and a 300W ATX for $10 more. Of course I wanted to get the 300W, but I knew that the one I was replacing was an AT, so I got the 250W to play it safe.

Could I have used the ATX? All my mainboards have both AT and ATX type connections.

Thanks

Str8jakit

[Barney]

I think besides the connector(s) for on the mobo there's one difference: softswitch.You don't turn the computer on off by a normal switch,on/off 220/12 V,but by a button.The mainboard is waiting for a signal to turn on from the button.

In AT computers the computer will turn on when it gets power,when it doesn't get power,it goes off (duh).ATX computers always get power but the comp doesns't go on because of the softswitch.

Maybe I didn't explain it to good,but I think you get it.

Ronald

Btw,you could use an ATX power supply on all those computers,although you would have to use a button to turn the computer on/off,AT cases have a switch.Switches don't work with ATX to turn the computer on/off.You could use the reset button for it.

[This message has been edited by Barney (edited 09-30-2000).]

[Ed_S]

An AT machine's MB connector is a single row of pins, usually having two wire connectors from the P/S.
ATX uses a double row, single connector.

AT has wire from P/S to front panel on switch, which is a double-pole, single throw type. (simple on/off)

ATX has wire from MB to switch, which is a momentary contact type.

ATX can be powered down via Windows "Shut Down" command, but AT must be physically turned off. ATX always has power to the MB, but AT does not.

The motherboard is usually what determines which type supply is required. With both connections available, you could use either but would need the proper switch.

Unless the machine's really loaded with drives & devices, a 250 will be fine. You just saved $10 plus the price of a switch! http://sysopt.earthweb.com/forum/smile.gif

Ed

[str8jakit]

Thanks, guys. The computer only has 1 HD and 1 CD-ROM. I was going to take the 300W (if I had gotten it) and put it on MY computer, which is pretty loaded. Then I would have put my present 250W on the kids' computer.

Oh well, I'm just glad the thing is working again and they have stopped bugging me to let them play their "Pokemon" games on MY computer.

Thanks again for the info.

Str8jakit