ELECTROMAGNETIC COIL DRIVE DEVICE

摘要

To provide an electromagnetic coil drive device which is configured to suppress the change of a current flowing into an electromagnetic coil so as to stabilize the current of the coil. The invention provides: a semiconductor switch (Q1) which is connected in series with an electromagnetic coil (10) so as to control a current flowing into the coil (10); a capacitor (C1); a comparator (30) which compares a voltage for charging/discharging the capacitor (C1) with two different voltages so as to generate a signal for operating the semiconductor switch (Q1) to turn on/off the semiconductor switch (Q1) in accordance with a result of the comparison; a charging circuit (50) which charges the capacitor (C1) based on a voltage applied to the coil (10); a charging circuit (60) which charges the capacitor (C1) based on a stabilized voltage; and a discharging circuit (70) which discharges the capacitor (C1). The charging circuit (50) has a resistor (R1), and compensating circuits (51 and 52) which are connected in parallel with the resistor (R1). In each of the compensating circuits (51 and 52), a resistor and a Zener diode are connected in series.