Fast-acting leakage detection and protection circuit with timing self-test function

Abstract

A quick-action leakage detection protection circuit with a regular self-checking function is provided. The quick-action leakage detection protection circuit may include a power input end, a power load end, a power user end, twin induction coils for detecting leakage current and low resistance failure, a control chip, a trip coil in which an iron core is disposed, a reset button, a self-checking chip, and a self-checking silicon controlled rectifier. The reset button may be linked with a main circuit switch, an analog path switch, and a normally-open self-checking path switch. The main circuit switch may include a pair of dynamic contact levers extended from the power load end, a first pair of static contact ends extended from the power input end passing through the twin induction coils, and a second pair of static contact ends extended from the power user end. In some embodiments, a first end of the trip coil may be connected to a live line end of the power input end and to the live line of the power load end via the first normally-closed switch. And, a second end of the trip coil may be connected to a neutral line end of the power load end via a second normally-closed switch.

Description

technical field [0001] The invention relates to the field of leakage protection, in particular to a fast-acting leakage detection and protection circuit with a timing self-check function. Background technique [0002] The leakage detection and protection circuit disclosed in the invention patent application with the application number of 201310452956.0 includes a power input terminal, a power user terminal, a power output terminal, a reset button, a main circuit switch linked with the reset button, and a dual circuit for detecting leakage current and low resistance faults. The induction coil, the tripping coil that drives the built-in iron core through the action of the magnetic field and cooperates with the mechanical structure to make the reset button drive the main circuit switch to close / open, the thyristor that provides a path for the analog leakage current, and the thyristor can be known through the detection results of the double induction coil The on-off control chip...

AI Technical Summary

Problems solved by technology

The application number is 201410112524.X. The invention patent application discloses a leakage detection and protection circuit with both timing self-test and reverse wiring protection functions. In order to realize the reverse wiring protection function and ensure the There are always two sets of conductors that are always kept on, that is, they are always two sets of isolated conductors. In addition to the main circuit switch, the circuit structure is also equipped with normally closed switches (K3B-1, KR3B-2), etc. The structure is more complicated and the assembly accuracy is required. High, more time-consuming and labor-intensive

The invention patent application with the application number 201410367800.7 solves the above problems, but correspondingly, there are also some shortcomings: two tripping coils are set, the structure is more complicated, and the processing and assembly are more inconvenient

[0003] The invention patent application with the application number 201410667103.3 provides a solution to the above technical problems, but the solution has the following disadvantages: 1. Both ends of the main circuit switch moving contact rod have moving contacts, and there is a seesaw structure in the middle. Processing, assembly and The action accuracy requirements are relatively high, and it is easy to cause poor contact during the internal pressure test (thousands of continuous on and off), and there are hidden dangers of failure; 2. There is a flexible wire connected under the seesaw-type moving contact rod, and the reliability of the flexible wire itself is difficult to guarantee. It will affect the action accuracy of the seesaw type moving contact rod; 3. There is no current limiting circuit in the reverse wiring circuit. If the main circuit switch cannot trip in time during the reverse wiring, the components (such as the tripping coil) may be damaged due to temperature rise; 4. Often The closed reverse wiring path switch K5 has its moving contact rod disconnected under pressure when the reset button is pressed and remains closed after the reset button is released from the hand. It requires high action precision and is difficult to process and assemble.

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