2-25
■ Printer mechanism drive control circuit
Print head solenoid drive circuit
The print head, a part of the printer mechanism, consists of
nine pins, each driven by a solenoid. (Refer to Section
2.2.2,
Printing mechanism
.)
The signals (HEAD1 to 9) applied to each of the print head
solenoids are output from ports PA7 to 0 and PC0 of the
gate array (U19).
The CROUT signal (pin 52) is the head conductance limiter
signal, and turns the head off if (due to misoperation) power
is supplied to the head for more than approximately 1ms.
The limiter time is determined according to the CR time
constant (C118, R157) of the signal input to the CRIN
terminal (pin 51), and is retriggered at the sitting edge of the
HD_COM signal (pin 21). (Refer to Figure 2-46.)
The head temperature can be determined by reading the
voltage (HD_TEMP signal) divided by the head coil resis-
tance and R145 through analog port AN1 (pin 80) of the
CPU (U19).
Figure 2-46. Print Head Printing Timing Chart
Figure 2-47. Print Head Drive Circuit
CONFIDENTIAL
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