Vacuum cleaner control circuit

Working principle of the circuit: As can be seen from the figure, lC and ruler, RP, C. and V.D. ,
VD, connected to form an astable multivibrator. The oscillation frequency is determined by the charge and discharge time
constants of the IC circuit. Charging time tcharge=0.693R1.c1, discharge time. t put =0.693RP.
C,. The charging time corresponding to the parameters in the figure is about 5s. The discharge time depends on the position of the sliding arm of the potentiometer
. At O. 30 s can be adjusted by yourself. The period of multivibrator T = t charge + t discharge =
0. 693 (R1 + RP) C1, and its period length and duty cycle can be adjusted. When power is first turned on
, pin 2 is at low level , which sets the IC, and pin 3 is at high level, the relay is closed, and
the motor M is powered to run, driving the wiper to swing. With C. By R. , VDz charging
, when C. When the potential on is higher than the trigger level of pin 6, 2/3 VDD, the circuit is reset,
pin 3 is low , the motor stops, and the wiper stops. C. The time corresponding to charging to 2/3 Vun
is the working time. cl through VD. , the internal discharge tube discharges from RP to 1C, and
the period of time during which it discharges to less than 1/3 Voo is the pause time. It goes round and round, running on its own.