audio electrical signal used as a switch tool
with an electricall audio signal coming from the pc (3,5mm,"headphones")is somehow posible built a "switch system" that switch-on two differents and independents circuits as the signal frecuencie reach some level?...one is switched at 4khz the other at 8khz.As long as the frecuencie is going on the circuit is
connected,the two circuits never work at once,and even none of them never work till some of the frecuencies arrive.There is only one pc sound file playing the roll, sound file that have the only two frecuencies that trigger the system
maybe an mini-relay 117-1-a-5/2d series very sensitive,maybe a transistor based circuit.they will connect a low level signal 3v. There is a need of some kind of amplification?so expensive for a bateries 3,7v that feed the whole circuit?and what about the filter
