Head Drive Circuit For Printer - Casio PCR-365A Service Manual

5-8. Head drive circuit for printer

Motor drive circuit
Normally, the transistor of motor drive circuit is followng condition.
TR1, TR2, TR5 :
TR3, TR4 :
MD (-) signal :
When the CPU want to rotate the motor, CPU change the MD signal to "High" from "Low".
Then, TR1, TR2 and TR5 are become ON and MD (-) signal is become GND level,
and then motor is rotated.
Head drive circuit
When the CPU wants to print, CPU send "High" signal from HD.A ~ HD.H terminal.
This signal goes to printer unit, and then print.
RP: Reset pulse from printer
DP: Dot pulse from printer
TR5
OFF
ON
VP level
— 13 —
TR4 TR3
TR1
TR2