Creepage detection circuit

Abstract

The invention provides a creepage detection circuit. The creepage detection circuit comprises a rectifying branch circuit, a capacitor, a bidirectional thyristor and an alarm module, wherein the rectifying branch circuit is electrically coupled to an equipment casing and consists of a resistor and a diode which are serially connected with each other; one electrode of the capacitor is electrically coupled to the rectifying branch circuit, and the other electrode of the capacitor is electrically coupled to the zero line end of a power socket; the bidirectional thyristor is electrically coupled to the capacitor; and the alarm module is electrically coupled to the capacitor and the bidirectional thyristor. When the equipment casing has a creepage phenomenon, the capacitor executes circulating operation of charging, discharging and recharging; and when voltage at the two ends of the capacitor is more than or equal to starting voltage of the bidirectional thyristor, the bidirectional thyristor is switched on and the alarm module outputs an alarm signal. After adoption of the creepage detection circuit, when the equipment casing has the creepage phenomenon, creepage voltage charges the capacitor, and when the voltage at the two ends of the capacitor is more than or equal to the starting voltage of the bidirectional thyristor, the bidirectional thyristor is switched on and the alarm module outputs the alarm signal, so that an operator is protected from personal injury caused by creepage of the casing.

Description

technical field [0001] The invention relates to leakage detection of various electric appliances, in particular to a leakage detection circuit designed with discrete components. Background technique [0002] With the improvement of material living standards and the development of science and technology, more and more large-scale industrial equipment such as servers and household appliances with professional purposes have been widely used to achieve various functions. Taking home appliances as an example, they are especially favored by the majority of users, freeing people from heavy physical labor. Usually, these home appliances all use 220V to 380V civilian three-phase AC power supply. When the power plug of the device is properly connected to the power socket, the device can work normally. [0003] However, many home appliances use metal materials as their shells. If the shell of the equipment leaks electricity, when the leakage voltage is higher than the safe voltage of ...

AI Technical Summary

Problems solved by technology

[0003] However, many home appliances use metal materials as the casing. If the casing of the device leaks electricity, when the leakage voltage is higher than the safe voltage of the human body, it is likely to cause life-threatening

In the prior art, when people use these devices, it is impossible to use a voltmeter to measure whether there is a leakage voltage in the equipment casing, and whether the leakage voltage will endanger personal safety

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