III. PEDESTAL MOTOR CONTROL CIRCUITA. OutlineFigure 8-301 shows the circuit that controls the pedestal motor (M1), and the circuithas the following functions:q Turns on and off the pedestal motorw Rotates the pedestal motor at a specific speedThe pedestal motor (M1) is a DC motor equipped with a clock pulse generator. Whenthe motor rotates, clock pulses (MMCLK) corresponding to the revolution of the motorare generated. The speed control circuit maintains the revolution of the motor bymatching the phase of the frequency of these pulses and that of the frequency of thereference signal.Figure 8-301B. MechanismWhen the pedestal motor drive signal (PEDMD) from the pedestal controller circuitgoes ‘1’, the drive circuit of the motor driver turns on, thereby rotating the pedestal motorat a specific speed.While the pedestal motor is rotating at a specific speed, the motor driver PCB sendsthe constant speed state signal (LOCK*=1) to the pedestal controller PCB. The signalgoes ‘0’ if the revolution of the motor fluctuates for some reason.If LOCK*=0, the operation of the machine is stopped, and ‘E901’ is indicated on thecopier’s display.CHAPTER 8 PAPER DECK PEDESTALCOPYRIGHT © 1997 CANON INC. CANON NP6330 REV.0 MAY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON) 8-5PedestalcontrollerPCBSpeedcontrolcircuitDrivecircuit DrivecurrentClock pulsegeneratorPedestalmotorMMCLKReference signal Motor driver PCBHall IC outputJ108-1 24VBJ109-1 PEDMD-2 LOCK*-3M1
