Industrial frequency invasion detecting method and device for outside connections of main distribution frame

Abstract

A detecting method of outside line power frequency invading for the main distributing frame has the features as the transducer being a current transformer with Bomo alloy core and its induction coil exporting DC signal via the process of bridge rectifier and RC filtering circuit, the signal to be sent into microprocessor chip via the amplifying of the operation amplifier, comparator and integrator formed by the operation amplifier as well as A / D converting, the chip to calculate out the integrate quantity of square and time of the current through software and to use it as basis for judgement, to export the alarm signal when the integrate quantity is bigger than the setting quentity and the alarm signal being exported by alarm control unit which is driven by power amplifier.

Description

technical field [0001] The invention relates to a detection method and a device, in particular to a detection method and a device for external power frequency (such as 220V or 380V voltage) invading a main distribution frame (MDF) of a fixed telephone network. The detection method and device can detect the intrusion of external power frequency in time, and make appropriate treatment after calculating the degree of damage, and send out an alarm signal when the value of the degree of damage is greater than the set value, otherwise continue to track and detect. Background technique [0002] The work of the fixed telephone depends on the fixed telephone network. With the continuous increase of fixed telephone users, the capacity and scope of the fixed telephone network expand rapidly, and the external lines are very complicated. Because the use of the user terminal is difficult to control, once the user uses it improperly, the external power frequency 22...

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