AC and DC digital input circuit

Abstract

The invention discloses an AC and DC digital input circuit. The circuit comprises an external control power supply circuit, a rectifying and filtering isolation input circuit, a detection isolation control circuit, a transient absorption circuit and a singlechip interface circuit. The circuit of the invention can realize AC and DC digital input signal acquisition without changing a hardware circuit structure; and the circuit is simple, reliable and low in cost. The circuit has higher practicability in the field of electrical engineering, particularly, in a power equipment protection device and an industrial automatic control situation.

Description

technical field [0001] The invention relates to an AC / DC digital quantity input circuit, which belongs to the field of electric equipment protection and industrial automation control. Background technique [0002] At present, in the field of power equipment protection devices and industrial automation control, it is necessary to detect the working status of contactors, circuit breakers and other equipment in real time or complete the triggering of some control signals. These functions can be realized through digital input. With the continuous development of the industrial level, the traditional low-voltage DC power supply digital input has poor anti-electromagnetic interference; at present, some equipment needs to use AC digital input for long-distance and simultaneous detection and control of multi-channel digital input. The amount of input heat is large; and the signal entering the single-chip microcomputer is a pulse signal, and the software processing is complicated. The...

AI Technical Summary

Problems solved by technology

With the continuous development of the industrial level, the traditional low-voltage DC power supply digital input has poor anti-electromagnetic interference; at present, some equipment needs to use AC digital input for long-distance and simultaneous detection and control of multi-channel digital input. The amount of input heat is large; and the signal entering the single-chip microcomputer is a pulse signal, and the software processing is complicated. The above defects reduce the reliability of the traditional AC and DC digital input equipment, and bury hidden dangers for the safe production of enterprises.

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