Method for suppressing passive wireless earphones by pulsed magnetic field

Abstract

The present invention relates to a method and an apparatus for suppressing passive wireless earphones through a pulsed magnet field. According to the method, a continuous pulse wave with the pulse duty factor of 50%:50% and a continuous pulse wave with the pulse duty factor changing within the range from 75%:25% to 25%:75% are adopted, a magnetic field coil is directly driven by superposition of base wave pulses and high-order harmonic pulses, an auditory discrimination mode of human is simulated, and reception of passive wireless earphones is suppressed, so as to interfere and destroy information transmission paths and conditions of cheating-used earphones. Various interference pulse signals are generated by a single chip microcomputer, and power complementary pair transistors are directly driven, the technology and the method are mature, reliable and easy to operate, and audio language classrooms or laboratory site facilities can be directly utilized.

Description

technical field [0001] The invention belongs to the technical field of communication, and relates to a method and a device for suppressing a passive wireless earphone by a pulsed magnetic field, in particular a method for interfering with and suppressing an audio miniature (or invisible) wireless earphone as a cheating tool and an electromagnetic field generating device. Background technique [0002] The invisible wireless earphones on the market are composed of several parts including strong magnetic earplugs, audio amplifiers, collar-type electromagnetic field sending antenna coils, batteries and audio cables. The explanation of Baidu Encyclopedia entry is "The invisible earphone is a kind of miniature wireless earphone, which can be divided into the following two categories from its appearance size and performance: according to its size, it can be divided into: rice grain earphones and rare earth earphones." The size of rice grain earphones and rice grains Generally, the ...

AI Technical Summary

Problems solved by technology

3G mobile phones are based on CDMA technology. The mobile phone jammers used in the early examination rooms did not contain 3G frequency bands, which immediately attracted the attention of cheaters and related industry chains to 3G mobile phones; the current 4G mobile phones are in the emerging communication frequency bands, and their frequency bands Wide, extremely difficult to cover completely

The interference suppression performance is directly related to the spectrum energy density. The more frequency bands that need interference, the lower the spectrum energy that can be allocated, which directly reduces the prevention effect.

The coverage radius of commercially available mobile phone jammers is small, only 10-20 meters, which makes it very difficult to prevent cheating in large-scale exams; at the same time, human body contact with high-power electromagnetic waves will cause discomfort

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