Inductive load drive circuit

Abstract

To provide an inductive load drive circuit capable of achieving high responsiveness in current reduction when an inductive load is stopped without generating heat, and capable of realizing highly efficient current control with higher response than conventional ones. In an inductive load drive circuit having a switching power supply circuit, as an energy recovery circuit that simultaneously recovers the counter electromotive force of the inductive load when the current of the inductive load is reduced, a recovery transformer is included in the same core as the inductive load Two primary-side coils different in resistance value and one secondary-side coil connected to the primary side of the switching transformer connected in series and opposite polarity to each other; and a recovery control element having a relatively small resistance value in the two primary-side coils The small-resistance primary-side coils are arranged in series, operate according to the pulse signal generated by the second pulse signal generator based on the recovery command signal from the control circuit, and control the current flowing in the small-resistance primary-side coil.

Description

technical field [0001] The present invention relates to circuits for driving inductive loads such as solenoid valves and motors, and more specifically, relates to inductive load drive circuits that control current by combining an energy recovery circuit with a circuit configuration of a switching power supply using a PWM control method. Background technique [0002] Inductive loads, such as motors and solenoid valves, which have a coil component and convert electrical energy into mechanical motion through electromagnetic force, are used as actuators in various devices. Inductive load drive control methods generally include pulse width modulation, so-called PWM (pulse width modulation, pulse width modulation) control, and proportional control. The former changes the duty cycle of the pulse width, that is, the on / off ratio according to the magnitude of the input signal when the load is turned on / off, and the latter changes the load at both ends of the control element connected...

AI Technical Summary

Problems solved by technology

[0009] In this way, in the inductive load drive circuit using the circuit structure of the PWM switching power supply, although the efficiency is high, there is a problem with the responsiveness, and the control of the reduction speed of the inductive load current cannot be realized.

On the other hand, the proportional control method is a method of controlling by variable adjustment of the voltage at both ends of the control element and allowing it to be lost, so there is a problem of heat generation

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