Re: [CAD_CAM_EDM_DRO] computer power supply

Tim Goldstein wrote:

> Sounds like you have a ATX style power supply, not the older AT. An AT style
> (2 single row plugs hook to the mother board) have a separate switch that
> turns them on or off. They will turn on with or without a load, but will not
> regulate properly with no load.

Not so. Most PC power supplies of the AT variety will produce excessive
'voltage and trip the crowbar in the first few switching cycles with no load.
I even had a computer that I upgraded, and I had to add a dummy load
on the +5, as the motherboard and drives didn't draw enough to keep the
power supply on. Symptom was the fan would 'twitch' when the switch
was flipped to on.

> An ATX style (a large double row plug to the
> mother board) does not have a separate switch and is normally controlled by
> the motherboard (OK, it may have a master switch on the back, but still
> needs the MB to turn it on). To use an ATX there is some combination of
> wires going to the big plug that you connect together to turn it on.

True, and it also has more voltages (+3.3 V), but it probably needs a
dummy load on at leaast one voltage, too.

Jon