Hi all I was wondering if it would be possible to us one of those bluetooth key locaters like tzumi tag it or magic finder to activate a transiistor to be used as a switch to turn this circuit on and off? If so what type of transistor would i need? The BT devices both have audio outputs as well as leds that flash that i could tie into to turn on the transistor therefore closing tthe circuit below correct?

 

I would use a N channel mosfet, like the Irf640, IRF510, IRF540, series.

Plenty to choose from..

http://www.futurlec.com/TransMosIRF.shtml

 

But how would I incorporate it in the circuit?

 

The same way, you feed a positive voltage to the gate, and the drain pulls down to the source, its the same principle.

If you have an audio output you will need to rectify it to a dc voltage.

 

I think the place to tap would be the flashing led that only flashes when you trigger it to from the phone, i want the on off effect to toggle if you get what i mean?