Scanner Motor Control - Ricoh FT7770 Service Manual

30 April, '89

Scanner Motor Control

2.
The main board controls the scanner speed with an 8 bit code
The scanner motor control board reads the code and converts it to an
analog signal (D/A converter).
verting amplifier to the driver circuit.
driver circuit by feedback signals from the motor and control signals from
the main board.
If the motor trigger signal stays LOW longer than 2.03 seconds the timer
will expire and disable the scanner motor control board.
The following is a brief discussion of the input and output lines.
-Scanner Motor Control Board Input to Main Board-
Using two signal lines, LEAD and LAG, the CPU
direction
of the
The driver circuit supplies power to the motor.
scanner motors is correct.
The analog signal is supplied through an in-
It is modified before it reaches the
2-18
(B0 to B7).
checks that the speed and