Ultrasonic anti-collision circuit

Shown is the ultrasonic anti-collision circuit. The circuit uses LM1812 and the time base circuit II controls the sending and receiving of LM1812
(LM1812, that is, sending and receiving). The control distance can be adjusted with Skfl's potentiometer, which can generally be controlled at 2-3m.
    Time base circuit 1 forms a monostable circuit. When the alarm distance is reached, pin ② of time base circuit 1 inputs low level (equivalent to 1/3Vcc),
the monostable circuit is triggered, and pin ③ outputs high level. The LED lights up and the electronic buzzer sounds an alarm. The ultrasonic sending/receiving sensor of this circuit
adopts T/R-40 series. This circuit can be used as an anti-collision alarm when the car is reversing and can be installed at the rear of the car. It can also be used for anti-theft alarms.
When a thief enters within 2 to 3 meters, the alarm will start. It is used in households, warehouses, finance and other departments.