First, thanks so much for taking the time to read this. I'm in a pickle as I don't know much about circuit design.
I'm quickly trying to build a simple circuit (well two actually) that will detect one of two signals and activate a relay. The relay can be anything from 5v to 12v actuation @ 5 amps... nothing big.
The audio signal can be anything, but it should be able to actuate two discrete relays. So, the audio output should split into a Y and then feed two different bandpass circuits, tuned to very widely different frequencies (e.g. 100Hz and 8KHz).
I've looked at the circuit design for a bandpass filter:
My question(s):
1). What kind of op-amp should be used? 2). Will making a very high Q filter boost the voltage to something like 5volts or do I need a second stage of op-amp gain? 3). If I do need second stage, anybody have one in mind which would be able to actuate a 5volt relay?thanks for any and all help you may be able to impart.
-sincerely robb kunz snipped-for-privacy@yahoo.com