Water and electricity saving infrared control circuit

1)'Power circuit: The power circuit consists of step-down, rectifier, filter and voltage stabilizing circuits.
    2) Infrared oscillator and infrared transmitter circuit: In the figure, the two non-r] Dl, D2 in the inverter and the peripheral Ri, brother, RP1, C
constitute a self-excited multivibrator, and its oscillation frequency is as follows: Calculation formula:, =0. 445/(岛十RRPl)Ci, the oscillation frequency used in this example is 38kHz. The
square wave output by the oscillator is current-limited and then amplified by the transistor\rri to drive the TLN104 infrared transmitter (VD5) and cause it to emit
modulated infrared light radiation waves.
    3) Infrared receiving and amplification demodulation circuit: Assuming no one washes hands at this time, the emitted infrared light will be radiated through the space without being reflected to the infrared
receiving tube VD6, and the solenoid valve YV will be in a static state. The opposite is true when someone washes their hands. At this time, since the transmitting tube and the receiving head are installed
at a distance of less than 20 cm, the included angle is 60°. On the left and right pool planes, infrared rays can be refracted by the human body and returned to the end
face , and are input into the integrated block 1C1 for infrared ray special reception through VD6, so that the internal frequency selective amplifier frequency selective amplification: after detection and shaping ,
then the ① pin outputs a low level , and then the inverter D3 inverts the output to a high level.
    4) Water supply delay circuit: The inverter D3 inverts and outputs a high level, and the identification circuit R9 and G of the water discharge electromagnetic terminal are delayed.
The capacitor C8 is charged by R9 and is charged to the power supply voltage of 2Vcc/ At 3 o'clock (the delay circuit of 2s is set up to prevent the
electromagnetic ), the inverter D4 outputs a low level, the transistor VT2 is saturated and turned on, and the relay Kl Pull-in, the normally open contact Kl
also closes, turn on the working power supply j of the solenoid valve YV to make the electromagnetic pull-in? Provide water to those washing their hands.
    5) Photosensitive control lighting circuit: The other high level output by D3 is sent to the center contact of the detection point RP2 of D5 through R]o. If it is daytime
, the photosensitive resistor RG will be exposed to light and its resistance will drop to Within lkfl, in this way, even if D3 outputs a high level, the voltage
is divided by the resistors Ru, RP2, and the photoresistor RG, and the movable contact of the trimming resistor RP2 is appropriately adjusted so that the input level of the NOT gate D5 is at Va:/3 below,
so its output is still high level, and then the inverter D6 flips and outputs low level, causing the transistor VT3 to cut off, the relay K2 does not act,
its contact K2 does not close, and the lighting does not light up.
    At night, there is no light on the photoresistor, and its resistance is a dark resistance (almost infinite), which is equivalent to an open circuit. At this time, when the output of D3 is high level,
the input level of the NOT gate D5 is higher than the value, so the output of D5 is low level. , the inverter D6 outputs a high level, the transistor VT3 is saturated and turned on, the relay
K2 is closed, the normally open contact K2 is also closed, and the light bulb HL is powered to light up to provide lighting for the person washing hands. When the person washing hands leaves after using up the water, the infrared receiving
tube cannot receive the signal from VD5 (TLN104), and the NOT gate D3 outputs a low level. The charge on the capacitor Ca is quickly
discharged , that is, the transistor VT2 immediately changes from saturation to When it enters the cut-off state, the relay Kl is released, its contact point Kl is opened, and the electromagnetic Y Y
quickly closes and stops the water supply at the moment when the person leaves. The values ​​of resistor R1 and capacitor C are chosen to be larger. The NOT gate D5 flips and outputs high voltage even when the person leaves, while
the diode VD3 is reverse-biased and cut off. The capacitor needs to be charged slowly through the resistor Riz, and waits for about 3mm until G reaches the upper end. When the voltage is charged to: 2VCr/3, it turns to
low level , D3 loses the base bias and exits saturation and is cut off, the relay K2 is released, the contact K2 is opened, and the bulb HL automatically goes out.
    6) Drive execution circuit: The drive execution circuit is mainly driven by relay Kl-, and the normally open contact Kl is also closed, turning on the
working , causing the solenoid valve to close, supplying water to the person washing hands, and also turning on the lighting. circuit to make the light bulb HL shine. On the contrary, the normally open contact of the relay is disconnected,
cutting off the solenoid valve and lighting circuit, and turning off the water and lights.