Figure shows the automatic change of wind speed control circuit. The circuit includes a clock signal generator IC1, counters IC2, decoder IC3, simultaneous phase-shifting circuit (BG1, BG2, BG3), SCR control circuit SCR, buck rectifier circuit. One step-down voltage after rectification in (9 ~ 10.5) V, to provide power for the entire controller.
Is the clock signal generator from the IC1 (555), R2, R3, W1, W2, C3 and other components of the multi-vibrator, the signal frequency depends on the charge and discharge time constant, and by adjusting the W1, W2 to change the signal The frequency and duty cycle. IC1 The low-frequency square wave pulse as a count of IC2 and add to the CP side (14 feet). The corresponding synchronous decimal counter IC2 (C192) produced by A, B, C, D4-bit binary code added to the decimal decoder IC3 (CD4028), with the addition of CP, which translated to BCD code at the output Q0, Q1 ... Q8, Q9 was high in order to provide for the wind speed change gear the basis for automatic transformation.
Synchronization phase circuit IC3 can change the output signal in order to change the SCR SCR conduction angle, the motor terminal voltage changes in order to achieve the 10 wind speed automatic transformation.