Multifunctional vision protector

The circuit consists of an infrared transmitter, an infrared receiver, a photometric circuit, a timing circuit and an alarm sound circuit. The infrared transmitter is a modulated transmitter circuit, consisting of a main oscillator circuit, a modulation circuit and an amplification and transmission circuit. As shown in the figure below The infrared receiver is composed of infrared receiving tube PH302 and infrared receiving special circuit CX20106. The photometric circuit is composed of photoresistor R12, inverter F6, VT4, VT5 and light emitting tube LED (yellow). The timing circuit is composed of F10, R23, C11 , the output circuit is composed of VT8 and indicator LED (green). F10, R23, and C11 form a monostable trigger.