| 摘要 |
PURPOSE:To monitor the temperature rise of a driving coil by a simple circuit by employing a construction capable of applying a constant voltage from the same power source to the driving coil which is energized by a constant current at temperature monitoring time. CONSTITUTION:When monitoring the temperature rises of driving coils L1 to Ln, a test signal of H level is input to the base of a transistor Tr5, and the prescribed constant voltage is applied by a resistor R2 and a Zener diode ZD1 to the base of a transistor Tr1. Thus, the prescribed voltage is applied to the coils L1 to Ln. The current values which flow to the coils L1 to Ln are detected by a resistor R1, and input to a temperature monitor 3. The input voltage is compared with a voltage at normal time, and the result is notified to a controller. Thus, the temperature can be monitored with a simple construction. |
