Ultrasonic remote control delay light switch circuit

This example introduces a delayed light circuit that uses ultrasonic waves as remote control commands. When using it, just press the ultrasonic
remote control transmitter and the light will light up. After a delay of about imln, the light will go out on its own. It is very suitable for
use when getting up temporarily at night.
    The ultrasonic remote control delay lamp consists
of two parts: an ultrasonic remote control transmitter and
a receiver. The transmitter
circuit is exactly the same as the above example
, see Figure 223 (a), and the receiver
circuit is shown in Figure 224.
    The time base circuit A2 is connected as
a typical monostable trigger.
Normally, the circuit is in a stable state.
The ③ pin outputs a low level,
the thyristor VTo is cut off, and the light F does not light up. If you need to turn on the light, just press the remote control transmitter. button SB, the ultrasonic transducer nl radiates ultrasonic remote control
instructions to the empty towel . At this time, the B2 of the receiver converts the received super signal into an electrical signal, which is amplified by VT3, and then sent to the VTd electrode by (j, ^note A VTd, causing VT4 to conduct instantaneously , that is, i∞A2 ( The ② pin of ixiF,.105) inputs a negative pulse, A2 is set to enter the transient state, and the ③ pin outputs high level . VTJ is turned on, and the lamp E lights up. At this time, the ⑦ pin of A2 is suspended, and the 12V positive power supply passes through R. Charge to C., about T = 1 1R., (1; when OK, the level of pin ⑥ of the time base circuit rises to 2/3VDL), the transient ends, the circuit returns to the original stable state, and pin ③ recovers Low level, wr:) turns off the stored AC fU when it crosses zero, and the lamp E goes out.     The receiver power supply is supplied by 220V AC power through (1, step-down, VD3 rectification, vs stabilization and (,. filtering). It is required to use a CBB type capacitor with a voltage of 400V or more. vs is preferably a 12V, 1W voltage stabilizer. tube . VTo is a micro-triggered unidirectional thyristor such as the 2N6065 type. The UCWI-T-10 and Lf (, M-R40 pressure-sensitive ceramic ultrasonic transmitting and receiving transducers for ni and B2 Zaipeng . Other components are particularly special. Require.