SU757895A1 - Device for reproducing random vibration spectrum - Google Patents

Description

The invention relates to a vibration technique and is intended to reproduce random vibrations with a given spectrum.

A device for reproducing a spectrum of random vibrations is known, comprising a spectrum specifying unit, a band-pass filter, a random signal generator connected in series, an amplifier with automatic gain control, a power amplifier, a vibration stand, a vibration sensor _g detector, a low-pass filter and a block comparison, the second input of which is connected to the block, which sets the 15th spectrum, and the regulating input of the amplifier with: automatic gain control connected to the output of the comparison unit [1].

The disadvantage of this device 20 is low accuracy due to simultaneous powering from one generator.

The purpose of the invention is to increase accuracy, 25

This goal is achieved by the fact that the device is equipped with two switches and a memory unit, the input of which is connected through one switch to the amplifier output with auto-

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By adjusting the gain by a tomato, and the output through another switch to the input of the power amplifier, and the band-pass filter is tunable and located between the random oscillator and the amplifier with automatic gain control.

NSG drawing shows a block diagram of the device.

The device comprises a block 1, a spectrum driver, a series-connected random signal generator 2, a tunable band-pass filter 3, an amplifier 4c with automatic gain control, a power amplifier 5, a vibration stand 6, a vibration sensor 7, a detector 8, a low-pass filter 9 and a comparison unit 10. To the second input of the unit 10 of the comparison is connected to the block 1, which specifies the spectrum. The regulatory input of the amplifier 4 with automatic gain control is connected to the output of the unit 10 of the comparison. The input of the memory block 11 through the switch 12 is connected to the output of the amplifier 4 with automatic gain control. The output of the memory block 11 through the switch 13 is connected to the input of the power amplifier ^.

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757,895

The device works as follows.

The signal from the generator 2 of random signals is fed to a tunable band-pass filter 3, where an electrical signal with a narrow spectrum (3-100 Hz) is extracted, then through the amplifier 4 with automatic adjustment of amplification, the switch 13th amplifier 5 of the power is fed to the shaker b. From the vibration sensor 7, the signal enters the detector 8 and the low-pass filter 9, where the selection of the constant component of the signal occurs, which corresponds to the acceleration dispersion in the frequency band corresponding to the tuning of the tunable band-pass filter 3. the actual values of the acceleration variance in the adjustable frequency band. In accordance with the error signal sets the gain of the amplifier 4 with automatic gain control. After this, switch 12 closes and the corrected signal is recorded in memory block 11. At the end of the recording, the switch 12 is opened, and the tunable bandpass filter 3 together with block 1 is transferred to the next frequency band.

Then the whole correction process is repeated. In block 11 of the memory, electrical signals are successively accumulated corresponding to each adjustable frequency band. At the end of the correction mode, the switch 13 is set to another position, and if at the stage of correction to the vibrostand narrowband random signals were applied, then now the vibrostand receives a random signal with the required spectrum. The accuracy of spectrum formation increases due to the complete elimination of the mutual correlation between signals in different frequency bands of the formed spectrum due to the time shift between individual implementations recorded in the memory unit.

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Claims (1)

Claim about A device for reproducing a spectrum of random vibrations, containing a block that specifies a spectrum, a band-pass filter, a series-connected random signal generator, an amplifier with automatic gain control, a power amplifier, a shaker, a vibration sensor, a detector, a low-pass filter and a comparator, to the second input which is connected to the block, which specifies the spectrum, and the regulating input of the amplifier with automatic gain control is connected to the output of the comparator, about and in conjunction with the fact that, in order to increase the accuracy, about but it is equipped with two switches and a memory unit whose input through one switch is connected to the amplifier output with automatic gain control, and the output through the other switch to the input of the power amplifier, and the band-pass filter is tunable and located between the random oscillator and the amplifier with auto? matched gain control.