Common control circuit generally have the following types: voice, light control, radio remote control. voice is to use voice to control the object moves, the general electret microphone or piezoelectric sensor to pick up the sound as, after driving through the amplification level electronic circuit switching. In order to prevent outside interference with the audio, you can control the use of ultrasound, but there are also deliberately used to control audio, such as with a child to control the frequency of the sound of laughing and AT24C02N-10SI-1.8 datasheet and crying action doll voice and AT24C02N-10SI-1.8 price and so on. simple single-channel light control circuit is to use the photodiode after the resistance to change by the light that changes the state of electronic switch, sensor photodiode, phototransistor, photoresistor, light-sensitiv...