Subsonic fan speed control remote control circuit diagram

It can realize remote control switching and speed adjustment of electric fans , and can also realize remote control of other household switches. Its main feature is that the transmitter uses a sub-ultrasonic transmitter, which has no directional restrictions, requires no power supply, and is durable. The sub- ultrasonic signal received by the piezoelectric buzzer is amplified by V1, frequency selected by L and C4, and then amplified by V2 and outputs pulses. Every time you operate, pinch the transmitter, and the V2 collector will output a positive pulse trigger signal, which is counted by the decimal counter CD4017. Use the Q1, Q2 and Q3 gears of CD4017. When the fourth signal arrives, the IC is cleared. The IC controls the transistor to drive the relay. The contacts of the relay are connected to the speed regulating coil of the original speed regulator to change the speed of the electric fan. The circuit can be expanded to 9 channels with slight modifications.