Auto power-on signal sensing circuit

[Slanski62]

I recently bought a Parasound amp with a signal-sensing automatic power turn on function. I have become thoroughly spoiled by it, I must admit. The problem is that I now want to use a DAC between the signal and the amp. Of course, the DAC must be turned on the old fashioned way.

Does anyone have knowledge of how an auto turn-on feature could be added to the DAC? Any information is much appreciated.

Steve

[maczrool]

I've never made one, but perhaps using a microcrontroller with ADC and a relay this could be done. The micro would sample the signal input and once some programmed threshold is met, it would trigger a relay circuit.

Stu

[cliffforrest]

Originally posted by maczrool
I've never made one, but perhaps using a microcrontroller with ADC and a relay this could be done. The micro would sample the signal input and once some programmed threshold is met, it would trigger a relay circuit.

Stu

Somewhat overkill there

A bridge rectifier, long time constant R / C network and a transistir driven relay is all that is needed.

[maczrool]

Not really overkill just different. A simple 8 pin micro with internal oscillator would do fine and might even cost less than an RC + bridge.


Stu

[jean-paul]

I would be surprised if it was actually cheaper.

[deandob]

Here you go:

http://sound.westhost.com/project38.htm

Regards,
Dean

[Slanski62]

Dean, thanks very much!

Steve