| 摘要 |
PURPOSE:To protect a drive circuit, in the logic circuit of a printer control part, by constituting the same of a drive voltage detection circuit, CPU having A/D converting function and a printing head drive cutting circuit. CONSTITUTION:A circuit consists of a voltage detection circuit 1, CPU 2 having A/D converting function, a drive cutting circuit 3 and a drive circuit 4. In the voltage detection circuit 1, the voltage of a driving power source VDRV is divided by R1, R2 and the voltage level at an a-point is inputted to the A/D converting terminal of CPU 2 to be compared with the level preset on the side of CPU and, when the drop at the a-point is detected in the OFF-state of the power source, an output signal (b) is set to a high level and Tr1 and Tr2 of the drive cutting circuit 3 are turned OFF to stop the operation of the drive circuit. By this constitution, a driver system is protected and the driving of a motor printing head pin after the power source is turned OFF is contracted within a short time.
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