1. The remote control is mainly composed of a microprocessor chip, a crystal oscillator, amplifying triode, remote control accessories ，infrared light-emitting diodes and a keyboard matrix that constitute the remote control signal.
2. The scanning signal generator inside IC1 generates 5 scanning pulse signals at different times, which are output from pins 5 to 9 and sent to the keyboard matrix circuit. When a key is pressed, the corresponding control signal of the function key is input to the key control encoder from pins 10 to 14, and the digital signal of the corresponding function is output.
3. Then the instruction code signal is output by the finger encoder, and modulated on the carrier signal by the modulator to form a high-frequency pulse train containing functional information. After the output of pin 17 is amplified by the triode BG, it drives the infrared light-emitting diode D to send out pulse modulation. Signal.
like:
