AU-X095 - Sharp Air Conditioner Service Manual (repair manual). Page 16

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This is an internal oscillator circuit to operate the CPU IC1 itself. The externally mounted ceramic oscillator, ceramic
condenser and resistor yield a stable 8.00 MHz oscillation. The ceramic capacitor is built into OSC1.

The outdoor unit control circuit is composed of an electronic control circuit centered around the outdoor control PCB
and an inverter for generating the voltage applied to the compressor.

The outdoor control PCB is constructed around a CPU. It receives the serial signals sent by the indoor unit, and
generates various corresponding signals in response. At the same time, it provides additionalcontrol for the outdoor unit
itself, resulting in overall control of the air conditioner.

The inverter controls the frequency of the compressor rotation. It operates the IPM according to the control signals sent
by the outdoor control PCB. The PWM method allows free control of the frequency and voltage, giving a wide range of
performance variations.

The 5V voltage is divided across R46 and R47 and the analog voltage is input to CPU IC1 pin 8. The CPU converts the
analog voltage to a digital value using an internal AD conversion circuit to select from among 8 models.

5V

R46

R47

CPU (IC1) pin 8

OSC

CPU (IC1) pin 10
CPU (IC1) pin 11