Power supply discharge at power off.

[DavidDLC]

I have a power supply based on the LM regulator series, when the power supply is turned off, it takes long time to discharge.

I have a voltage panel meter connected to it, and don't like the fact that the LCD will go off after some (long) time after shutting down the unit.

So is there a technique to automatically discharge faster the power supply when turned off ?

Something I can add to the power supply output (without modifying the existing PS), but of course the idea is that when the PS is on this circuit will present a small load to the PS.

Please comment or suggest.

[Zero999]

Use a double pole switch, one pole for the mains and the other for the DC side but make sure the switch has adequate isolation between poles.

[DavidDLC]

Good idea, but I want to avoid changing the current PS and would like to add something to the output.
 
I also would like to avoid mechanical devices like relays or switches.

[Time]

Why would you want to avoid a relay?  Thats the typical solution for this situation, that or the switch as mentioned.

[Zad]

Surely a 10k or so bleed resistor will drain the caps in not-very-long without massively compromising the drive current?

[alm]

Surely a 10k or so bleed resistor will drain the caps in not-very-long without massively compromising the drive current?

This also seems the obvious solution for me. Especially since this doesn't look like an application that need to conserve every last uA.

[Zero999]

A small incandescent lamp is probably idea as it will also function as an additional power on indicator which will prove the meter is working properly.

[NiHaoMike]

Use a watchdog chip to monitor the transformer secondary. Could be as simple as a charge pump based on a few discrete capacitors and diodes.

[Simon]

just fiddle with some resistor values and see hos small a value you need to discharge it in the amount of time you want, then see if your happy with the current draw of that resistor when power is meant to be on