Hitachi RAM-71QH5, Service Manual

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12. Power Factor Control Circuit
Power factor is controlled by almost 100%. (Effective use of power)
With IC in ACT module, control is performed so that input current waveform will be similar to waveform of input
voltage.
I (input current)
V (input voltage)
input voltage
input current
Effective
voltage
area
Effective
voltage area
Invalid power area
(Even if voltage is applied. current does not flow
*Assuming the same current capacity (20A), power can be used about 10% effective, comparing with curent use
(power factor of 90%), and maximum capacity is thereby improved.
Pin No.
12V
0.9V
200ms
75ms 50ms
42
41
40
39
Fig. 11-2
With expansion valve control, opening degree is adjusted to stabilize target temperature, by detecting
temperature of compressor head.
The period of control is about once per 20 seconds, and output a few pulses.