Leakage blocking protective circuit

Abstract

The invention relates to a leakage blocking protective circuit. The leakage blocking protective circuit comprises a detection comparison module (A), a detection time-delay module (B), a blocking circuit module (C) and a signal output module (D), wherein an input end of the detection comparison module (A) is connected with a peripheral detected equipment insulation resistor so as to detect insulation performance of the detected equipment insulation resistor, comparing a detected equipment insulation resistor value and an insulation critical value and then outputting the detected equipment insulation resistor value. The detection time-delay module (B) is connected with an output end of the detection comparison module (A) so as to prolong detection time of the detection comparison module (A). The blocking circuit module (C) is connected with the output end of the detection comparison module (A) and feeds back output signals of the detection comparison module to the input end of the detection comparison module (A) to form blocking. The signal output module (D) is connected with the detection time-delay module (B) so as to output passive contact signals to ban power transmission to a major loop of the detected equipment and to achieve leakage of electricity blocking protection of the detected equipment. The leakage blocking protective circuit can output the passive contact blocking signals and guarantee security of power supply.

Description

technical field [0001] The invention relates to an electrical device, in particular to a leakage blocking protection circuit of electrical equipment. Background technique [0002] The underground working conditions of coal mines are special, and the environment is humid, which has high requirements on the insulation performance of electrical equipment and cables. According to coal mine safety regulations, the control equipment of low-voltage motors and low-voltage feeders should be equipped with leakage locking protection devices. Therefore, before the main circuit of mine electrical equipment is energized, the insulation performance of the equipment needs to be tested. Once the insulation performance drops below the specified value , it will prohibit the power transmission to the main circuit, and realize the leakage blocking protection function of the equipment. [0003] Among the existing leakage lock protection circuits, one type is composed of digital circuits such as ...

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Problems solved by technology

[0003] Among the existing leakage lock protection circuits, one type is composed of digital circuits such as a CPU control unit (such as a single-chip microcomputer) (for example: Patent No. ZL200920144489.4). This method requires the CPU control unit to be programmed, and the circuit structure is complex. The cost is high; there is another type that directly uses a comparator to form a detection circuit, but this circuit has low reliability, is prone to misoperation, and has poor anti-interference ability

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