slight bug with this loudspeaker protection circuit

kier

Jul 6, 2012
2
Joined
Jul 6, 2012
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2
i put this cct together to suit my needs of a) delayed turn on of the relay; b)fast turn off when amp is switched off; c)dc dectection; d)powered from the amps main rails of around +/-57V.

the front part does the dc dectection, and i joined it up to another cct i had come across, for the delayed turn on and fast turn off.

it works most of the time, but now and then the relay drops out after a few minutes from switch on and then after 5-10 mins slowly powers up again; another time the relay failed to energise at all after the switch on.

View attachment 41736

 
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