SU1623574A3 - Method of inspecting speakers for detecting mechanical flaws - Google Patents

Abstract

The invention relates to instrumentation, in particular to methods for controlling loudspeakers, and can be used in conditions of enterprises producing loudspeakers. The purpose of the invention is to improve the quality of control. A piezoelectric vibrator is installed on a fixed part of a loudspeaker. , to the level at this frequency and the level of broadband random vibration in the high frequency range lying above the mechanical Resonance elements loudspeaker design comparing the measured values with limit certain audio on the test results and i ri increase of at least one of the limit values of -1's conclude ialichi, de4ekta yl loudspeaker 2

Description

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The invention relates to instrumentation, and in particular to methods of controlling loudspeakers, and can be used in conditions of enterprises producing loudspeakers.

The purpose of the invention is to improve the quality of control

Figure 1 shows the dependence of the EDS self-induction ratio of the transducer to the acceleration amplitude of the moving system on frequency; figure 2 - block diagram of the device implements the method

The method is based on the physical principle of forming a working loudspeaker. When a loudspeaker is functioning normally, its coil suspended on a centering washer makes a reciprocating motion. In this case, vibration is mainly transmitted to the loudspeaker case. which leads to deformation of the vibration spectrum. High-frequency components in the including multiples of the fundamental frequency, the ratio of the total level of which to the magnitude of the excitation is the first measured parameter. The second measured parameter is the level of broadband vibration measured in the high frequency range above the mechanical resonance of structural elements. The limit value of the measured parameters is determined by the results tests of loudspeakers with a diagnosed defect

Monitoring the loudspeakers for mechanical defects is performed as follows. The loudspeaker case is installed; a piezoelectric vibration transducer excites the loudspeaker with a harmonic test signal; measure the vibration of the fixed part of the loudspeaker and extract the measured parameters from it. Then, the measured values of the parameters are compared with the limiting ones and, if at least one of them is exceeded, they conclude that there is a defect in the loudspeaker.

The device contains a series-connected harmonic signal generator 1, power amplifier 2 and loudspeaker 3 under test. A piezoelectric vibrator 4 is installed at the fixed part of the loudspeaker, which converts the mechanical oscillation of the loudspeaker into an electrical signal. The output of the vibration converter is connected to the input of the amplifier 5 and to the inputs of the measurement channels, which consist of a series-connected high-pass filter 6 or band-pass filter 7, threshold devices 8 and 9, and signaling devices 10 and 11 exceeding a predetermined level.

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Claims (1)

The invention of the method of monitoring the loudspeaker for the presence of mechanical defects, including the excitation of a moving system loudspeaker by harmonic signal and measurement of high-frequency components of voltage, characterized in that, in order to improve the quality of control, the vibration of the fixed part of the loudspeaker is recorded, the ratio of the total level of vibration components, multiple of the excitation frequency, to the level of vibration components at this frequency and broadband vibration level in the high-frequency range lying above the zone of mechanical resonances of the elements of the loudspeaker design, the measured values are compared with the limiting and 6 presence of defects of the loudspeaker by the court in excess of at least one of the limiting values. / 7 Fig, 1