Leakage current detection device for appliances

Abstract

A leakage current detection device includes a self-test unit for activating a simulated leakage current signal; a leakage current detection unit for detecting the simulated leakage current signal and the actual leakage current signal, where when at least one of them is present, the leakage current detection unit activates a trigger signal, and when both of them are absent, the leakage current detection unit deactivates the trigger signal; a self-test feedback turnoff unit for detecting the trigger signal, where when the trigger signal is detected, the self-test feedback turnoff unit deactivates the simulated leakage current signal before a predetermined time point; and a power line disconnect unit for detecting the trigger signal after the predetermined time point, and when the trigger signal is detected, it disconnects the power between the power source and the load.

Description

BACKGROUND OF THE INVENTIONField of the Invention[0001]This invention relates to the field of electrical appliance and related circuitry, and in particular, it relates to a leakage current detection device and electrical connection device incorporating the leakage current detection device.Description of the Related Art[0002]Electrical appliances are widely used, and their safety is an important issue. Leakage current detection devices are provided for safety purposes. Leakage current detection devices that employ a relay and have both leakage current detection function and self test function are available.SUMMARY OF THE INVENTION[0003]In a leakage current detection devices that have both leakage current detection function and self test function, the self test signals sometimes interfere with actual leakage current signals. For example, the self test signals may be superimposed on the actual leakage current signals, or cancel out the actual leakage current signals. Embodiments of the...

AI Technical Summary

Benefits of technology

[0003]In a leakage current detection devices that have both leakage current detection function and self test function, the self test signals sometimes interfere with actual leakage current signals. For example, the self test signals may be superimposed on the actual leakage current signals, or cancel out the actual leakage current signals. Embodiments of the present invention provide a leakage current detection device and electrical connection device incorporating the leakage current detection device that can avoid such undesirable effects, and can ensure that the leakage current detection function and the self test functions do not interfere with each other.

[0005]Using the above structure, the detection of the actual leakage current occurs after the simulated leakage current is deactivated, and based on such detection, the power source is disconnected. Therefore, the simulated leakage current will not interfere with the actual leakage current, which improves the reliability of the device and improves safety.

[0013]In one embodiment, the delay sub-unit is an RC circuit. This can achieve the delay using a simple structure.

[0017]In summary, embodiments of the present invention can separate the self test function and the leakage current detection function in the time domain, in order to prevent the simulated leakage signal from interfering with the actual leakage signal. As a result, the leakage current detection device can more accurately detect actual leakage current signals, which improves safety.

Problems solved by technology

Electrical appliances are widely used, and their safety is an important issue.

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