Infrared sensor faucet automatic handwasher circuit

Circuit working principle: The power supply part is step-down and rectified through the transformer, and then passes through the three-terminal voltage stabilizing
block 7805 to supply power to the special circuit KA2184 and the infrared emission circuit . vr,, VT2,
R. ,C. Forming a 40 kffi oscillator, its output drives the 5G L to emit infrared rays. When washing hands,
the infrared rays emitted by 5GL are reflected by human hands, received by photoelectric tube 3DUI1, and then sent to
lC for processing. lC amplifies, filters, detects, compares and shapes the 40 kHz signal
, and then outputs low level from pin 7. R6 and VD2 control VT3 from off to on
, the solid state relay TAC018 is triggered and turned on, the solenoid valve is powered on, and the faucet
discharges water. After washing hands, the hands leave the faucet. Photoelectric tube 3DU11 cannot receive the infrared ray emitted by 5G L. Pin 7 of IC outputs high level, VT3 is cut off, TAC018 is cut off, the solenoid valve is de-energized, the faucet is cut off, and a hand-washing water supply process is completed.