Toner Motor Control Circuit - Kyocera FS-1800 Service Manual

Toner motor control circuit

As TMOTON at #15 of gate array (U204) turns to H, Q218 and Q217 turn on, and +24 V reaches
Q217, R265 and the toner motor, finally driving the toner motor.
If the toner motor is overloaded by some reasons, an overcurrent may flow through the toner motor
beyond the predetermined level, turning Q220 on. Q220, when turned on, causes the current from
the +24 V power supply to flow through Q217, Q220, R267, R268, and to the ground. Consequently,
approximately 3.9 V (H) develops at point A, as limited by the combination of R267, R268, and
DZ206. This voltage is used as TNMOC - toner motor error - which is applied to #17 of CPU
(U201). Thus, CPU determines the toner motor error and lets Call service person E9 be
indicated.
CPU
U204
TMOTON
TNMOC
FS-1800/1800N | FS-3800/3800N
Engine board
Toner motor control circuit
Q218
15
2
TMOTON
17
TNMOC
Figure 4-3-8 Toner motor control circuit
+24V2
1
3
1
GND
1
2
Q220
R266
3
R267
R268 DZ206
GND
4-30
3 Q217
2
R265
YC203
16
TMOTDR
9 GND
GND
Toner
motor