Voice-activated toy car circuit
Posted on Dec 11, 2010 12614
Electric cars represent the voice circuit principle, when to speak, against sound signal received by a drop in the body into a microphone BM and telecommunications weak number,
G via a capacitor coupled to an integrated circuit O feet, by the internal amplifier IC emblem weak signal amplified, and then by the pin output, amplified signal is coupled via a capacitor C4 and C input to flip-flop together end a ? feet and legs. The Q output of bistable circuit connected buffer punch drive control transistor VT off and turned on. If the original bistable circuit output terminal is low, the transistor is turned off, external relay K release. The sound sensor receives sound, the bistable flip the circuit is high, crystal tube by the deadline becomes saturated conduction, the relay pull-K, was charged with motor power and start working. When the sensor receives external sound again, Q goes low again, crystal transistor is turned off, the relay K release, accused the motor to stop working. After the microphone whenever they receive a signal circuit bistable flip once, will relay the action again.