Leakage protection plug

Abstract

The invention discloses a leakage protection plug. Electrical shock hazards caused by failures of electric appliances as well as accidental electrification of a ground wire can be prevented. A first resistance-capacitance element, a second resistance-capacitance element, a photoelectric coupler and a trigger circuit are also arranged on the leakage protection plug, wherein a detection loop which is formed by connecting the first resistance-capacitance element, one input end and the other input end of the photoelectric coupler, and the second resistance-capacitance element in series is connected between the ground wire and a zero wire; a signal output by the photoelectric coupler is sent to the input end of the trigger circuit; and the output end of the trigger circuit is connected with the control end of a driving circuit of an electromagnetic coil.

Description

technical field [0001] The invention relates to the technical field of electricity safety protection, in particular to an electric leakage protection plug. Background technique [0002] Chinese patent document CN1142618C discloses a leakage protection plug. The leakage protection plug is not only equipped with a zero-sequence current transformer through which both the phase line and the neutral line pass, but also has a ground wire live detection sensor through which the ground wire passes. Therefore, it can not only detect whether there is residual current between the phase line and the neutral line at the load end, but when there is a residual current between the phase line and the neutral line and reaches the preset threshold value (for example: 10mA), it will be within 0.1S It trips immediately to cut off the phase wire, neutral wire and ground wire; and when the ground wire is accidentally electrified due to an abnormal grounding protection system, it can also detect wh...

AI Technical Summary

Problems solved by technology

figure 1 Shown is an existing optocoupler 100, its input end is composed of a neon lamp 100-1 to form a light-emitting element, and its output end is composed of a phototransistor 100-2 to form a light-receiving element, from the characteristics of the neon lamp 100-1 we can know , the starting voltage of the neon lamp 100-1 usually needs to be about 85V or above. It can be seen from this that when the leakage protection plug uses this kind of photocoupler 100 to detect the voltage between the ground wire and the neutral wire , this kind of leakage protection plug has the following disadvantages: when the voltage between the ground line and the neutral line is lower than 50V (for example: 24V), the neon lamp 100-1 inside the photocoupler 100 in the detection circuit will be If it cannot be lit, the photocoupler 100 cannot work normally, and cannot send a signal to trip the leakage protection plug. Therefore, using this kind of photocoupler 100 as the leakage protection plug of the detection element cannot guarantee the safety of people using electricity. Purpose

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