Sharp AY-ZP35PR Service Manual page 21

AY-ZP35PR
IPM
detection
5. 120° Energizing control (digital position detection control)
This control system detects the digital position detection signal and adjusts the rate of acceleration/deceleration accordingly.
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tion signal is generated as a reference voltage equaling 1/2 of 280 VDC. However, since there is no induced voltage waveform when
the PWM waveform is OFF, the microcomputer performs internal processing so that detection is enabled only when it is ON. Based on
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racy is high.
The microcomputer performs internal processing to cancel spike voltage during the regenerative process.
Furthermore, even if the induced voltage is low, position detection is still possible, thus allowing sensor-less operation at low rotation
speed in the initial stage of operation.
This reduces the starting current and improves the IPM reliability.
Spike voltage
(cancelled)
P
N
overcurrent
CiN
circuit 26
FO
24
Terminal voltage waveform
Shunt resistance
Overcurrent
R49
Reference voltage
(1/2 of DC voltage)
Comparator output waveform
(Position signal waveform)
2-16
5V
IC1
34
0V
51 56