DRIVE DEVICE FOR ELECTROMAGNET COIL

摘要

Provided is a drive device for an electromagnet coil that suppresses variations in current flowing in an electromagnet coil and stabilizes the coil current. The present invention is provided with: a semiconductor switch (Q1) that is connected in series with the electromagnet coil (10) and controls the current supplied to the coil (10); a capacitor (C1); a comparator (30) that compares the voltage of the charging and discharging of the capacitor (C1) with two different voltages and generates a signal that carries out an on and off operation for the semiconductor switch (Q1) according to the results of the comparison; a charging circuit (50) that charges the capacitor (C1) on the basis of a voltage applied to the coil (10); a charging circuit (60) that charges the capacitor (C1) on the basis of a stabilized voltage; and a discharging circuit (70) that discharges the capacitor (C1). The charging circuit (50) is provided with a resistor (R1) and compensation circuits (51, 52) connected in parallel with the resistor (R1). Each of the compensation circuits (51, 52) have a Zener diode connected in series with a resistor.