Operation - Canon NP6251 Service Manual

CHAPTER 2 BASIC OPERATION

2. Operation

a. Turning On and Off
When the main motor drive signal (M1ON) goes '1', the phase comparison circuit and
the frequency circuitry shown in Figure 2-107 send control signals.
The control signals from both circuits are combined and sent to the motor drive
circuit, turning on the motor drive circuit and rotating the main motor.
When M1ON goes '0', on the other hand, the output of the control signal stops and
remains so, keeping the motor stationary.
b. Controlling to a Specific Speed
The rotation of the machine's main motor is controlled to a specific speed.
The reference signal generating circuit on the motor control PCB generates
reference pulses which are sent to the phase comparison circuit and the frequency
comparison circuit.
The phase comparison circuit generates control signals (phase comparison signals)
so that the phase of the clock pulses (MMCLK) from the main motor matches that of the
reference signals.
Likewise, the frequency comparison circuit generates control signals (frequency
comparison signals) so that the frequency of the clock pulses (MMCLK) from the main
motor matches that of the reference pulses.
After both phase comparison signal and frequency comparison signal have been
combined, they are sent to the motor drive circuit for control of the power to the main
motor, thereby keeping the revolution to a specific number.
3. Detecting an Error
When an excess load is imposed on the motor for some reason, the DC controller
PCB will detect a fault in the clock pulses from the main motor and, as a result, will
indicate 'E010' and an error message on the control panel.
2-12
COPYRIGHT © 1997 CANON INC.
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CANON NP6350/NP6251 REV.0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)