Leakage detecting protection circuit capable of periodically automatically detecting function integrity

Abstract

The invention provides a leakage detecting protection circuit capable of periodically automatically detecting function integrity. The leakage detecting protection circuit comprises a main loop switch, a resetting button, a tripping coil, a silicon controlled rectifier, an induction coil for detecting leakage current, a self-induction coil for detecting a low-resistance failure and a control chip which drives the switching-on / off of the silicon controlled rectifier by a leakage current detection result, and further comprises a) a timer for periodically outputting a function integrity detection signal, b) a detection signal latching circuit, c) an analogue test switch for generating analogue leakage current, d) a delay output circuit and e) a sampling circuit, wherein the timer outputs the detection signal to the latching circuit and the delay output circuit; and if a function is detected to fail, the delay output circuit outputs a tripping signal to switch the silicon controlled rectifier on, and the main loop switch is switched off. The leakage detecting protection circuit has the main advantages of periodically automatically detecting whether the leakage protection function of the circuit is integral or not without annual testing and avoiding tripping within the service life of the circuit, along with more convenience of use.

Description

technical field [0001] The invention relates to a leakage detection and protection circuit applied to electric appliances such as power sockets with leakage protection function, and in particular to a leakage detection and protection circuit that can automatically detect the functional integrity at regular intervals. If the leakage protection function is intact, the detection process will not trip. If the function is damaged, it will trip automatically. Background technique [0002] With the continuous development of the power socket with leakage protection function (referred to as GFCI), power plug and power switch industry, people have higher and higher requirements for the function and safety of power socket with leakage protection function and power plug, so this Such products need to be equipped with a corresponding leakage detection protection circuit. When a leakage current occurs during use, it is necessary to trip in time and disconnect the power supply in time. In ...

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Problems solved by technology

[0002] With the continuous development of the power socket with leakage protection function (referred to as GFCI), power plug and power switch industry, people have higher and higher requirements for the function and safety of power socket with leakage protection function and power plug, so this Such products need to be equipped with a corresponding leakage detection protection circuit. When a leakage current occurs during use, it is necessary to trip in time and disconnect the power supply in time. In addition, a manual test function must be set, that is, a simulated leakage current is generated by human operation to make it trip, such as the application number A leakage detection and protection circuit was published for the 201010237744.7 invention patent application, including a main circuit switch, a reset button, a trip coil that can cooperate with the mechanical structure to disconnect the main circuit switch, a thyristor that controls the power supply circuit of the trip coil, The induction coil used to detect leakage current, the self-induction coil used to detect low resistance faults, and the control chip that drives the thyristor on and off through the leakage current detection result, etc. This circuit needs to manually press the test button to generate a simulated leakage current to Detect whether the life of the circuit is terminated, but cannot automatically detect whether the leakage protection function is intact

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