Novel and practical multi-channel infrared remote control switch circuit

The remote control switch introduced in this article works reliably, is simple to debug, and can realize nine-way control. Used to remote control various household appliances and devices that require multi-channel control. The entire circuit consists of two parts: transmitting and receiving. Transmitting circuit As shown in Figure 1, the encoding is completed by a pulse telephone number dialing integrated circuit CIC9110. When any key "1~9" is pressed, the special pulse generator outputs the corresponding high-level pulse from its ⑨ pin, and its speed can reach 20/second. These pulses are directly sent to the ① pin of A to control the gated oscillator composed of gates A and B. Its oscillation frequency is about 38kHz. Then it is buffered by gate C to push VT1, and the modulated infrared light is emitted from the infrared light-emitting tube. Pulse signal. The receiving circuit is shown in Figure 2 (only one control circuit is shown). When the power is turned on, D3 converts the received infrared pulse into a weak electrical signal. After amplification by the operational amplifier IC2, its ⑥ pin outputs the original encoded signal. D5 , D4, R, and C constitute a pulsating rectifier circuit, and IC2 is the main device to complete multi-channel control. Here are some examples. When D3 receives 4 pulses, VT2 is saturated and conducts 4 times, and its collector inputs 4 counting pulses to the CP terminal of IC4 (IC4 is a decimal counting/pulse distributor). At this time, after counting and decoding by IC4 , its ④ terminal is always high. After a short delay of R12 and C10, the voltage regulator tube D7 is broken down, VT3 and VT4 are turned on, and the high level is added to the R terminal of IC4 through D6 to reset it. At the same time, VT5 is turned on instantaneously. . At the moment of conduction, VT5 provides a current to the J1 winding to cause its contacts to close, and the power supply of the controlled load is connected through the J1 contact. J1 is a new type of bistable memory self-locking relay, whose contacts can rely on internal machinery to maintain a locked state without the need for power. When the transmitter key No. 4 is pressed again, the receiver repeats the above working process and the J1 contact is released. It is worth noting that although the ① and ③ terminals of IC4 also output high level (about 50mV), due to the delay effect of R12 and C10, it is not enough to cause the voltage regulator tube to breakdown, and it will not cause 1, 2, 3 circuit action, and only when a certain terminal is constant high can the subsequent circuit be triggered. This is the key to this remote control. 3DG130D, 9014, 9015 and other transistors in the component selection circuit can be used if their β value is greater than 100; D7 is a 2V/0.5W Zener diode; the capacitors are all ceramic capacitors except those marked as electrolytic capacitors; the resistance is 1 /16W metal film resistor; J1 uses the new domestic ZS-01F self-locking relay. There are no special requirements for the remaining components.