A leakage blocking sampling circuit and detection method

Abstract

The invention discloses a leakage blocking sampling circuit and a detection method. The detection circuit is used to inject a DC signal into the leakage resistance to be tested and collect the feedback signal of the leakage resistance to be measured, and transmit the collected feedback signal to a π-type filter circuit; The π-type filter circuit filters the collected feedback signal, and feeds the filtered signal back to the adaptive filter circuit; the adaptive filter circuit is used to separate the AC signal from the filtered signal and reversely superimpose it to the filtered signal. The signal, and the AC signal in the filtered signal cancel each other to obtain the wave clipping signal, and then transmit the wave clipping signal to the shaping circuit for level adjustment and then output, which can effectively eliminate the influence of the residual voltage on the detection circuit. The adaptive filter circuit can effectively suppress the influence of the clutter induction voltage on the detection results, and the adaptive filter circuit can solve the influence of the residual magnetic voltage on the leakage blocking detection circuit and the damage of the back-feeding current to the leakage blocking circuit.

Description

Technical field [0001] The present invention belongs to the explosion-proof appliance technology, which relates to a leakage-chain lock sample circuit and a detection method. Background technique [0002] Leakage-leakage lock is the insulation resistance of the feed switch or the electromagnetic starter-load side of the disconnection state. If it is below the set value, it cannot be connected to power, which belongs to preventive detection, and contains the coal mine and contains Preventive detection protection in flammable and explosive environments is especially important; [0003] image 3 For the existing low-pressure feed-driven, the electrical lock detection is often put into detection simultaneously on the switch main contact Km, but due to the wiring distribution capacitance, the test object already has the presence of the induction electromotive force, which can be simplified to the right side equivalent. The circuit, that is, an AC voltage source series capacitor then i...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a leakage blocking sampling circuit and a detection method to overcome the problems of low detection accuracy and inaccurate detection in the existing method that the back-feeding current is easy to damage the detection circuit and the residual magnetic voltage affects the leakage detection circuit.

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