audio priority circuit

[mMrOler]

Hi,

I'm looking for a circuit with 2 inputs and 1 output that would switch of input 1 and switch on input 2 whenever a certain threshold is reached on input 2.
I would use this to switch of my mp3 player in order to listen to my(yet to be acquired) walkie talkie.
Would it be possible to also switch of input one during transmitting?

[Rerouter]

it is not hard to do, it just depends on how long after crossing that threshold you would want it to remain on the walky talky input, so that you dont have have it crossing back between words,

here would be your circuit, a peak detector,
http://tinyurl.com/ck39qpa

the 470K and 10uF make an rc network so that it resets after about 1.8 seconds,
and the 2 op amps are being used as comparitors to drive the n channel mosfets,
and the 5V between them would be your threshold level,

hope it helps

[Hobgoblin612]

An easy way to do it would be to use a VOX switch kit like this one: http://www.jaycar.com.au/productView.asp?ID=KC5172

Then just switch the relay to a DPDT one.

[mMrOler]

Thanks, I will definitely solder up the circuit. Btw, the circuit simulator is pretty cool.

I came across the VOX switch as well, yet I'm not sure how to replace the microphone with a direct output from the walkie.

Thanks guys!