Building A Digital Relay?

[SonyQrio]

So here's how it's supposed to work:

There is an LED on my audio amp, probably 3v on the + pin when it's turned on. When I press the power button on the amp, I want to somehow build a relay (or equivalent) to give 7.4v to my power regulators. Any ideas?

Thanks,
SQ

 

[ttsgeb]

I think I may have heard of something that can help with that...

 

[SonyQrio]

So you're saying I can use a single transistor? Schematic?

 

[ttsgeb]

http://lmgtfy.com/?q=using+a+transistor ... tal+switch

http://www.electronics-tutorials.ws/tra ... ran_4.html

There you go, Mr. Prodigy.

 

[SonyQrio]

All prodigies are a protègè. Thanks for being my mentor!