Electromagnetic coil drive device

摘要

An electromagnetic coil drive device has a semiconductor switch connected in series with an electromagnetic coil for controlling a current supplied to the coil; a capacitor; a comparator for comparing a voltage to charge and discharge the capacitor with two different voltages, for generating a signal to operate on-off of the semiconductor switch in accordance with a result of a comparison; a first charging circuit to charge the capacitor based on a voltage applied to the coil; and a discharging circuit to discharge the capacitor. The first charging circuit has a first resistor and at least one compensating circuit connected in parallel with the first resistor; and a resistor and a Zener diode are connected in series in the compensating circuit.

主权项

1. An electromagnetic coil drive device, comprising:
a semiconductor switch connected in series with an electromagnetic coil for controlling a current supplied to the coil; a capacitor; a comparator for comparing a voltage to charge and discharge the capacitor with two different voltages, for generating a signal to operate on-off of the semiconductor switch in accordance with a result of a comparison; a first charging circuit to charge the capacitor based on a voltage applied to the coil; and a discharging circuit to discharge the capacitor; wherein the first charging circuit has a first resistor and at least one compensating circuit connected in parallel with the first resistor, and the compensating circuit includes: a first compensating circuit in which a second resistor and a first Zener diode are connected in series, and a second compensating circuit in which a third resistor and a second Zener diode are connected in series; and the first Zener diode and the second Zener diode have different Zener voltages.