Simple and universal infrared remote control receiving circuit

Nowadays, TV, VCD, VCR and other infrared remote control transmitters are more common in households. This circuit is designed for their performance, allowing the remote control transmitter to play another purpose: emitting infrared signals and controlling lighting fixtures with a control distance of >8 meters. . Circuit principle: This circuit is shown in Figure 1, which is an infrared control switch circuit mainly composed of an infrared receiver and IC4069. The infrared receiver outputs high level when it is static. When receiving the infrared pulse signal from the remote control transmitter, the first pin of the receiver outputs a low level (pulse signal). The negative pulse signal is obtained through shaping, amplification and inversion by ICa, which is then detected by D5, C4 and R3 and sent to ICb with a delay (reaching the threshold voltage of the inverter), causing ICb to output a low level, and then the voltage at the C4 terminal is R3 discharges, making the ICb input end lower than the threshold voltage of the inverter, and the ICb output end returns to high level. In this way, every time the infrared transmitter is pressed, a negative pulse signal will be obtained at the output end of IC6 to trigger the bistable circuit composed of ICC and ICd, causing the bistable circuit to flip and output H or L level through R8 Control the conduction or cut-off of the one-way thyristor, and then control the lighting and extinguishing of the lamp. The 220V AC power is rectified and stepped down by D1~D4, R1 and C1 to provide +5V DC voltage for the circuit. Debugging and Precautions: As long as the components are installed correctly, you can power on and measure the voltage of the TC4069 pin, which is generally around +5V. If the voltage is too low, adjust the resistance of R1 appropriately. The empty consumption of this circuit is extremely small, and the measured power consumption is less than 1/2W. Note: The circuit board has high voltage, so be careful when testing to prevent electric shock. Component selection: The DC internal resistance of the infrared receiver is relatively high and the working voltage is +5V (see Figure 2). The unidirectional silicon controlled SCR should have the same power as the selected incandescent lamp to prevent over-current breakdown.