MOTM

>Well, the problem is where are you going to get your low voltage to operated
>the relay?  With the power supply off, you have no low voltage source to
>pick up the relay.  I suppose you could do something with a rechargeable
>battery that gets charged when then PS in turned on.
>
>You could put in a separate low voltage wall wart that was always on to
>provide your low voltage power for your relay circuit.


I don't like the idea of using a second walwart supply/cable to power 
the relay...

...Maybe (if they exist, I don't know if they do) a relay that runs 
on mains AC, that has a separate non powered circuit to switch the 
relay. Then it could use the same mains AC that is going through the 
relay to operate it.

...Battery, rechargeable or not, is a workable solution, not ideal though.

...Very small second internal power supply wired up after the rear 
panel power switch, but before the relay so it would always be turned 
on.

...Have the front panel switch turn the DC power on and off before it 
is distributed to the modules, but then the power supply would be on 
all the time.


I'm concerned with these last two examples about having the power 
supplies running all the time.

I could have a Stooge panel made for the power switch, with battery 
holder if need be for a battery, and status leds for AC power before 
and after the relay, for the battery level, as well as status leds 
for each DC power rail.


Simon
Canberra
AUSTRALIA