Air Conditioner Remote Control A microprocessor that forms a remote control signal
The remote control consists mainly of a microprocessor chip, a crystal oscillator, an amplifying transistor, an infrared light emitting diode, and a keyboard matrix that form a remote control signal.
Working principle and performance characteristics
The oscillator in chip IC1 internally generates a high-frequency oscillating signal (480 kHz) by means of a high-frequency oscillator consisting of 2,3 pins and an external oscillating crystal X. This signal is sent to the timing signal generator to produce a 40KHz sinusoidal signal and a timing pulse signal. The sinusoidal signal is sent to the code modulator as a carrier signal; the timing pulse signal is sent to the sweep signal generator, the key input encoder and the instruction encoder as the time standard signals for these circuits.
IC1 internal scanning signal generator produces five different time scan pulse signal, from 5 to 9 feet output to the keyboard matrix circuit. When a key is pressed, the control signal corresponding to the function key is input from 10 to 14 feet to the keying encoder, respectively, and the corresponding digital signal is output. And then by the encoder output instruction code signal, through the modulator modulation in the carrier signal, the formation of functional information containing high-frequency bursts, by the 17-pin output through the transistor BG amplification, to promote the infrared light emitting diode D pulse modulation signal.
Appearance performance requirements include the following:
(1) the appearance of the remote control can not have scratches, fouling, cracking, burr, mildew, coating coating and loose structure and so on.
(2) the battery cover can not fall off, the battery spring can not rust.
(3) LCD screen can not have cracks, black spots.
(4) remote control surface pencil hardness of not less than 2H, there should be no obvious scratches.
(5) the remote control surface of the characters, signs and finishing parts should be clearly visible, the adhesion of 2 ~ 3 N cm 2 of the transparent tape pressure in the above-mentioned parts, hand plus a vertical force on the remote control surface, and then Quickly pull the tape, characters, signs and finishing parts can not fall off.
(6) remote control surface can withstand 60 ℃ warm water, 20 [%] of salt water, anhydrous ethanol, edible oil, the above items drop on the remote control surface, with a soft cloth dry, the remote control surface hardness and appearance should not Abnormal, characters, signs and finishing parts should be clearly visible
(7) the remote control of the button's load life of not less than 100 000 times, respectively, in the left, right, front and rear side of the application of 10N force after the release, the button should be completely reset, can not have card key phenomenon.