Current Control Circuit For Feed Motor; Drive Circuit For Fan Motor - Toshiba MR-3011 Service Manual

10.6 Current Control Circuit for Feed Motor

R131
PREM_LMT
This circuit is a current control circuit to control the current consumption by the DC+24V power supply, and
consists of a resistor for current detection and a voltage comparator.
Current supplied to the feed motor is converted into voltage at R90 and R91. If the voltage value is higher than
the reference voltage which is the total of R84, R88, R133 and ZD2, the output level of IC8 (comparator) is
judged as "L" and the feed motor is turned OFF. The feed motor is turned ON again when the current consump-
tion is decreased to the reference voltage or becomes lower.

10.7 Drive Circuit for Fan Motor

TP50
FAN_LOCK
TP51
FAN
This circuit controls the rotation/stoppage of the fan motor.
When the output level of CPU is "H", Q12 and Q16 are turned ON and drive the fan motor. At this time, a lock
detection signal is output from the fan motor and sent to the CPU. The level of the lock detection signal is "L"
during normal operation and becomes "H" during abnormal operation.
October 2000 © TOSHIBA TEC
+5V
1
TP32
2
-
1 7
IC8.2
+
R121
1 2
1
C64
2
R132
1
SGND
C 2
1
1
Q12
B
E 3
SGND
1
R133
1
R84
2
6
5
K 2
1
ZD2
R88
A 1
2
+5V
1
R76
2
1
DC+24V
E 3
1
2
Q16
B
C 2
10-6 MR-3011/3012 DESCRIPTION OF CIRCUITS
+24V
Feed motor
2
drive circuit
2 1
R79
1
C23
R91
2
PGND
2
FANLK
1
FAN
1 2 3
PGND
PGND
D13
2 2
R90
1 1
CN9.2
Fan motor
CN9.1
FAN
CN9.3