Is there a chip that can...

[soundNERD]

I need to know if there is some kind of chip that can attach to the input of an amplifier, and pull down a relay when a sihgnal is detected. What the relay does is switch on and off the amps.

Thanks, Mike

 

[ofb]

do you mean like a voice activated switch?
Voice activated switch - MC2830

 

[li_gangyi]

I think he wants some of those circuits that turn on the amp when there is a signal...like thpose subwoofer amps...which turn on automatically when there's an input...

 

[soundNERD]

Exaxctly li_gangyi, that is what I need. I have seen techinque used before in JBL computer spakers, and like you mentioned, subwoofers. I need it to control a split power supply. I guess if there are no chips that can do this, that is ok also.

 

[JOE DIRT®]

an optocoupler will meet your requirements for that purpose and be isolated from the load

 

[li_gangyi]

and do include a small delay...you don't want your amp to shut off when ur CD player is changing CDs or tracks...

 

[soundNERD]

Small delay as in LM555? Would I use the optocoupler as the trigger, and the relay as the output? I would set is for something like 5 min. mabye.

 

[Keld]

something like this ? (not a "one chip" solution): http://sound.westhost.com/project38.htm

DVC Keld

 

[li_gangyi]

yeah...that circuit looks pretty good...

 

[soundNERD]

Thanks for the help, everyone.

 

[li_gangyi]

noi problem...not sure if you can get a PCB for the circuit on Rod's site...check it out...