Micro air conditioning remote control
Internal oscillator IC1 by 2 or 3 feet with an external crystal x a high frequency oscillator of oscillations, high frequency oscillation signal (480kHz). 40KHz after this signal into the timing signal generator of sinusoidal signals and timing pulses. Sine signals into coded modulation using a carrier signal; pulsed signals sweep signal generator, keyed input encoder encoder and instructions as time standard signals of these circuits.
IC1 sweep signal generator within the five different scanning pulse signal time, output from 5~9 feet to the keyboard matrix circuits. When you press a key, the corresponding to the function key input control signals composed of 10~14 feet to the keying encoder, the output functions as a digital signal. And the script encoder output signal, modulated on carrier signal modulation form contains capability information of high frequency pulse trains from 17 feet out after transistors BG amplifier to promote infra-red LEDs d emits pulses modulating signal.