Sub-ultrasonic remote control light switch circuit (2)

It is a sub-ultrasonic remote control light switch circuit made of Suning integrated circuits . It consists of an acoustic wave transducer,
a frequency selective amplifier and a general Suning integrated circuit.
    Thyristor VT2 and diodes VD2~VD5 form the main concave circuit of the remote control light switch. The control loop
is composed of the acoustic wave transducer, namely microphone B, the frequency selective amplifier VRi and the CD4013 digital integrated circuit. Ri,
VD1, vs and G form a resistor step-down simple voltage stabilizing circuit. After power on, C. Both ends output about 12V DC
voltage for controlling the iLi circuit power.
    After the iSkHz sound wave signal is picked up by microphone B, the corresponding electrical signal is output, which is passed through C. Coupled to
the base of frequency selective amplifier VT1 for amplification. Its collector circuit is connected with,, and f: legacy frequency network, which vibrate at the 18kl[z
frequency. This has a better inhibitory effect on audio signals of other frequencies. Only the 18kHz sub-ultrasonic signal
is amplified. Ran b output is sent to the ③ pin of CD4 013 for processing.
    CD4013 is a dual flip-flop, which consists of a monostable circuit and a stable circuit. The Shan Suizhi
circuit mainly performs pulse broadening and shaping on the 18kHz signal output by VT1 to ensure reliable switching action every time.
When the lcP
terminal of 1D4013 (the ③ pin) receives the
18kHz pulse signal output by VT1
, the monostable
circuit switches, and its 1Q
terminal (the ① pin) outputs the island
level, which is sent to
the 2CF of the monostable circuit through the ⑩ pin. The terminal
turns it over, and its ? As long as A transmits an 18kHz remote control command once, the fork of the bistable idle circuit flips once, the ⑩ pin changes from high level to low level , VT? loses the main trigger voltage, the AC power is turned off when it crosses zero, and the lamp E goes out. The monostable circuit The transient time is determined by R, (1s), which determines the width of the positive pulse output by the monostable circuit to ensure reliable triggering of the bistable circuit.     The iSkHz arc ultrasonic generator still uses a rubber ball pressure-type ultrasonic whistle, and the sound wave transducer The instrument can be CRZ. 113F type and other common electret condenser microphones. It is required to use RJ-1W type metal film resistor, L is 2 2mH color code inductor. When debugging, you need to prepare several more with different capacities ( j. Test the capacitors one by one and select one that can make the remote control distance larger and solder it on.