Constant current drive circuit with wire break detection

Abstract

The invention discloses a constant current drive circuit with wire break detection, comprising load L1, sampling resistor R8, sampling resistor R9, sampling resistor R10, flywheel diode D2, switch tube N2, isolating chip U2, isolating chip Q2, isolating chip Q3 and control chip U1. The constant current drive circuit with wire break detection is simple in structure, drive current is convenient to control, wire break detection is convenient, the cost is low, controlling is flexible, failure rate is low, and the defects are overcome that an existing constant current drive circuit is complex in design, drive current is difficult to control, wire breakage is unable to be detected and the cost is high.

Description

technical field [0001] The invention relates to a constant current drive circuit, in particular to a constant current drive circuit for wire breakage detection. Background technique [0002] With the development of society and the progress of industrial control, industrial automation control has been popularized and widely used in all walks of life, but these control output control parts are still dominated by ordinary switches, which can meet the requirements for occasions with low requirements, but It is obviously incompetent for control occasions with high precision requirements. At present, the constant current driving circuit is mainly composed of a dedicated chip, an isolation circuit and a protection circuit, and the circuit design is complicated and the cost is high. At the same time, it is difficult to control the driving current of the existing constant current driving circuit, it is difficult to realize the preset current curve for output, and the current lag tim...

AI Technical Summary

Problems solved by technology

[0002] With the development of society and the progress of industrial control, industrial automation control has been popularized and widely used in all walks of life, but these control output control parts are still dominated by ordinary switches, which can meet the requirements for occasions with low requirements, but For control occasions with high precision requirements, it is obviously incompetent

At present, the constant current drive circuit is mainly composed of dedicated chips, isolation circuits and protection circuits. The circuit design is complex and the cost is high.

At the same time, the driving current control of the existing constant current driving circuit is relatively difficult, and it is difficult to realize the preset current curve for output, and the current lag time is long

[0003] And in some important occasions, whether there is a disconnection in the control loop is an important indicator, otherwise refusal to operate at a critical moment will cause serious consequences

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