Circuit local overheating protection trigger circuit and trigger method

Abstract

The invention discloses a circuit local overheating protection trigger circuit and method, and the circuit local overheating protection trigger circuit is characterized in that the trigger circuit comprises a temperature sensing element and a current limiting element, one end of the temperature sensing element is communicated with a power line, the other end of the temperature sensing element is connected with one end of the current limiting element in series, and the other end of the current limiting element is connected with a grounding line; according to the triggering method, the temperature sensing element detects the local temperature of the protected circuit, and when the local temperature of the protected circuit is higher than an allowable value, the temperature sensing element is connected with the circuit or the resistance value is reduced, so that grounding current larger than a set value flows between the power line and the grounding line; therefore, a leakage protector or a residual current circuit breaker of a preceding-stage circuit is triggered to cut off the circuit. According to the invention, protection triggering of local overheat of the circuit can be realized with low production cost, low maintenance cost and a simple structure, and the overheat protection triggering problem caused by overlarge local contact resistance at a wiring position, a wiring position of a line and a terminal and a contact point of a plug and a socket in the circuit can be solved.

Description

technical field [0001] The invention relates to the field of local overheat protection of circuits, and relates to a trigger circuit and a trigger method for local overheat protection of circuits, which are applied to overheat protection caused by excessive local contact resistance at connection points in circuits, connection points between lines and terminals, and contact points between plugs and sockets. Background technique [0002] In the wiring of the circuit, the connection between the line and the terminal, and the contact point between the plug and the socket, the local contact resistance will be too large due to reasons such as loosening or oxidation of the conductor surface, which will cause local overheating when there is a load current flowing in the circuit, which may ignite Combustible materials around may cause electrical fire. [0003] Existing trigger circuits and trigger methods for local overheating protection of the circuit, some use a simple temperature ...

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved by the present invention is to provide a low-cost, simple-structured, low-trigger current for the existing circuit local overheat protection trigger circuit and trigger method to achieve complex structure, high cost, limited reliability, and unsuitability for wide application. The circuit local overheating protection trigger circuit and trigger method

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