RCM series integrated circuit remote control circuita

The transmitting circuit is composed of only one wireless transmitting module A1, and the receiver is composed of a miniature wireless receiving module A2, a micro-power monostable trigger
A3 and other parts. A simple transceiver wireless remote control circuit
made of     RCM series integrated circuits . This circuit has the characteristics of simplicity, practicality and short transmission distance.     (1) Transmitting circuit The transmitting circuit adopts RC MIA special transmitting module, which is powered by 3V power supply. After the power is turned on, radio remote control signals are transmitted to the surroundings.     (2) The time base circuit A3 and transistor VT3 in the receiving circuit constitute a micro-power monostable trigger with a unique circuit design. The transistors are usually in a cut-off state. Therefore, the negative terminal of the power supply of A3, that is, the ① pin is disconnected from the ground, and the integrated block is in a power-off state, so no power is consumed , and the ◎ pin does not output voltage. At this time, the standby current of the whole machine is only the quiescent current of A2 plus the penetration current of the silicon transistor, and the total is less than ImA. If no special design is adopted, the static power consumption of the time base circuit NE555 is as high as 5-l(}mA.     When SB is pressed, the ② pin of the receiving module outputs high level VT1~VT3, and then the time base circuit NE555 is turned on one after another. Circuit A3 is powered on and works. Since VT1 is turned on, its collector's trigger terminal ② of the time base circuit is low level, so the time base circuit A3 enters a temporary stable state, and the output terminal ③ of the circuit outputs high level , all the way through the island point. The bright light-emitting tubes LED1 and LED2 emit light. At the same time, the two light-emitting tubes also serve as voltage regulator tubes, outputting about 3.2V DC voltage for external power supply. The other path charges to 0 through the =electrode V], because the charging time constant is extremely small, & The charge is quickly filled. #The base current is fed to the transistor VT through the resistor , causing VT3 to self-lock. That is, when the transmitter button SB is released, the ② pin of the receiving module returns to low level, although VT1 and VTZ are turned on from their original state. The state turns to the cut-off state, but VT3 can still remain on. Therefore, A3 can still work normally. In the transient state, the internal discharge tube of A3 is cut off and the t⑦ pin is left floating, and the positive power supply can charge the capacitor island through Rs, so that the integrated block The level of pin ⑥ at the threshold end continues to rise. When T=1. lRsc2, the level of pin ⑥ rises to 2/3Ⅵ)D, A3 resets into a stable state, pin ③ outputs a low level, and at the same time the internal discharge tube is turned on, so pins ⑦ and ① are short-circuited by the discharge tube, and the charge charged by c2 will be discharged through pins ⑦ and ① of A3. Due to the existence of capacitor C4, although the LED goes out when pin ③ outputs low level, VT3 can still maintain a short-term conduction state. The purpose is to enable A3 to maintain short-term operation and keep the internal discharge tube a conduction state, so that G It can be discharged quickly to provide charging conditions for the next remote control. After C4 charge is basically discharged, VT3 resumes cut- off, and the circuit returns to the original standby state.