Need Help Building a Relay Circuit
I am putting the finishing touches on integrating my Mac Mini to my VW Monsoon Amp.
I have the amp working thanks to the FAQ posts.
I would like to install a relay that uses the presence of audio current to switch on the 5v needed to turn on the Monsoon Amp. If you are unfamiliar the 5v is injected into the negative leads going to the amp.
The purpose of this circuit is to turn the amp on/off based on the presence of an audio current. When the current is present the audio sounds great. If I close the MAC applications or browser providing audio output then I get a buzz from the 5v being applied. So, the relay circuit would ensure that the amp is only powered when there is current on the audio output.
Mac Mini --------Analog out 3.5mm to L/R RCA------Ground Loop Isolator---------Circuit box (splits the RCA to 4 channels, adds 5v to the negative terminals)------Monsoon Amp
The relay would connect in the Circuit Box
RCA positive lead ------ Relay Magnet--------RCA positive lead out to amp
5v PSU ----------------Relay Switch-----------5V applied to negative leads
What relay should I purchase?
What is the current across the Analog audio signal which will be used to activate the relay?