2-30
Printer mechanism overcurrent detection circuit
The circuit shown in Figure 2-53 monitors the status of the
current flowing to each of the solenoids in the printer
mechanism (the clutch, platen switching, and slip switching
solenoids). When an overcurrent is detected, the CD_OFF
signal is turned on and is supplied to the P51 terminal (pin
16) of the CPU (U12).
When the CPU receives the CD_OFF signal, it stops sup-
plying the +24V voltage through the SW24V signal output
from the P60 terminal (pin 9).
Table 2-7. Solenoid Overcurrent Detection Signals
Signal Name
Source
Target Solenoid
CD_PLN
Bridge driver (QM5)
Platen switching solenoid
Pin 1 output terminal
CD_SJC
Transistor (Q40)
Slip holder switching
Emitter side
solenoid
CD_CLT
Transistor (Q41)
Clutch solenoid
Emitter side
Figure 2-53. Platen Switching, Clutch, Slip Switching Solenoids Drive Circuits and Printer Mechanism
Overcurrent Detection Circuit
CONFIDENTIAL
Summary of Contents for U375 - TM B/W Dot-matrix Printer
Page 2: ...Technical manual TM U375 U375P English 4005791 Copied Date 199 Copied by ...
Page 54: ...2 23 Figure 2 44 Host Interface Circuit and Custor Display Interface Circuit CONFIDENTIAL ...
Page 58: ...2 27 Figure 2 49 Carriage Motor Drive Signal Timing Chart CONFIDENTIAL ...
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