12v power supply quick off

Thread Starter

s200bym

Joined Aug 9, 2017
82
Hi guys,

I have a 240v ac to 12v 8A dc isolated power supply.

When I switch it off from the mains it’s has a slow shut off of around 3 seconds.

One of the spur circuits it is powering is a speaker protection board. Is there any way I can get this spur to shut off instantly?

Maybe some diodes and resistors in-line.

Kind Regards,
Mike.
 

gerty

Joined Aug 30, 2007
1,305
What you are seeing is probably the capacitors discharging. if you put a small load across the 12 volt side, such as a small bulb, I think you'll see it goes off quicker.
 

crutschow

Joined Mar 14, 2008
34,280
If gerty's cure doesn't work, you could add a 240Vac relay with coil connected to the power supply 240Vac input, and its NO contacts in series with the speaker protection board.
 
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