Development Drive Motor - Ricoh FT7770 Service Manual

30
April, '89

Development Drive Motor

9.
This copier uses a Hall effect motor to drive the development unit. A sepa-
rate development motor is used because the main motor's torque is insuffi-
cient. Hall effect motors have the following characteristics:
Good
o speed control (like a servomotor)
o Quiet and compact.
o High torque at low RPM
o Low electrical noise generation
- Power -
CN121-3 and CN121-1 receive 100 volts ac.
plied to the inverter for use as the main drive power for the motor. An ex-
ternal transformer provides 6 volts ac (x4) and 15 volts ac to the control
board.
The 6 volt inputs are rectified and regulated to +5 volts, which is
used to actuate the drive transistors of the inverter.
converted to +12 volts and +8 volts, which power the control circuit.
This input is rectified and ap-
2-40
The 15-volt input is