Fault detection circuit of relay and relay with the same

Abstract

The invention discloses a fault detection circuit of a relay and a relay with the same. The fault detection circuit comprises a contact voltage drop detection device and a signal output circuit. The contact voltage drop detection device detects voltage drops of two ends of a contact of the relay. When it is judged that two ends of the contact of the relay are in a fault state, the signal output circuit outputs fault signals to prompt that it is judged that the relay breaks down or fails. The contact voltage drop detection device comprises a comparison circuit and an optical coupler. The optical coupler detects to obtain contact voltage drop signals of two ends of the contact of the relay. When detecting that two ends of the contact of the relay have voltage drops, it shows that the contact of the relay is in a disconnected state. The output end of the optical coupler inputs a contact voltage drop signal to the comparison circuit. After the contact voltage drop detection device acquires the contact voltage drop signal, the contact voltage drop detection device outputs the acquired fault judgment signal through detection to a signal output circuit to judge and prompt that the relay is in a fault or failure state. Thus, the position where the system fault point is located can be quickly judged, the fault detection efficiency is high and fault loss is low.

Description

Technical field [0001] The invention relates to a relay, in particular to a relay for detecting the fault state of the relay contact. Background technique [0002] A relay is a commonly used electrical control device. It is an electrical appliance that causes the controlled quantity to undergo a predetermined step change in the electrical output circuit when the input excitation quantity changes to the specified requirements. It has an interactive relationship between the control system or input loop and the controlled system or output loop. Usually used in automated control circuits, relays are often used in actual circuits as a kind of "automatic switch" to control large current operation through small currents, and are widely used in many occasions, playing automatic adjustment and safety in the circuit Protection, conversion circuit, etc. Since the relay is an automatic switching element with isolation function, it is widely used in remote control, telemetry, communication,...

AI Technical Summary

Problems solved by technology

[0003] The present invention solves the defect that the existing relay does not have the self-detection on-off state and fault state, which leads to the occurrence of circuit faults easily, and when the control circuit fails, the location of the fault point cannot be quickly and accurately judged. , which brings delays to circuit fault detection and is not conducive to the current situation of the maintenance of the entire control system. It provides a method that can effectively detect the on-off status of both ends of the relay contacts, and can promptly determine the location of the fault point of the control system, improving circuit fault detection. Efficient relay fault detection circuit and relay with the circuit

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