SU756244A1 - Device for shaping broadband random vibration spectrum - Google Patents

Description

The invention relates to the field of test equipment, in particular to devices for shaping a spectrum of broadband random vibrations, intended for testing products for random vibrations.

A device for forming a spectrum of broadband random vibrations, comprising a noise generator connected to an adder and a vibration exciter with a vibration measuring transducer connected to a set of band-pass filters, is known. The outputs of the Bandpass Filters are connected to the comparison units through dispersion meters, the signals from the comparison units control the transmission coefficients of the attenuators, the inputs of which receive signals from the strips

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output filters. Attenuator outputs are connected to a common adder, which provides for adjustment of the feedback value.

A disadvantage of the known device is that the considerable depth of feedback necessary to ensure the dynamic range generates strict requirements for 30

the stability of the elements of the positive feedback circuit to eliminate the possibility of self-excitation of the device.

The closest to the invention to the technical essence is a device for forming a spectrum of broadband random vibrations, containing a white generator, parallel forming channels, each of which includes series-connected band-pass filter, dispersion meter, comparator, the second input of which is connected to a program voltage source and parallel circuits connected to the output of the bandpass filter, one of which contains a series-connected controlled key and attenuator, and - berating - cos union of sequentially controllable switch, and a phase inverter controlled attenuator, and in each of these circuits and the control inputs of the switch attenuator connected to the output of comparator unit through a sign-sensitive valve, an adder, connected to the input of which outputs of attenuators connected to the output of the adder exciter KO3

756244

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swan, measuring vibrator.

In the known device, parallel formation channels form a multi-channel feedback circuit in which one of the attenuators determines the amount of positive feedback and the other negative feedback [2].

However, controlling the vibration spectrum, regulating the depth of positive feedback, leads to an increase in the Q-factors of the channel signal spectra compared to the given ones. . The creation of dips in the spectrum of vibrations by regulating the depth of negative feedback leads to 15

a significant decrease in the quality of failures. These circumstances limit the types of spectra formed by a known device.

The purpose of the invention is an extension of 20

species formed spectra.

This goal is achieved by the fact that the device is equipped with a second adder, the inputs of which are connected to the outputs of a white noise generator and a measuring vibration transducer, and the output to the inputs of bandpass Filters, and a broadband filter whose input is connected to the output of the second adder. input __ the first adder.

The drawing shows a block diagram of the described device.

The device contains a white noise generator 1, a second adder 2 connected to its output, ³³ connected to the output of the latter, broadly. The glossy filter 3 and parallel formation channels, each of which includes .sequentially connected band pass. filter 4, meter 5 of Persia 40, comparison unit 6, the second input of which is connected to the voltage source of the program (indicated by the arrow with the index 11 _pr ), and also parallel circuits connected to the output of the bandpass filter 4, one of which contains a serially connected controllable key 7, a phase inverter 8 and a controlled attenuator 9, and the other one is a serially connected controllable key 1.0 and a controlled atom tenuator 11.

The outputs of all attenuators 9. and 11 and the output of the broadband filter 3 are connected to the inputs of the first sum - ³³ torus 12,. The output of which through a power amplifier (not shown) is connected to the input of the exciter 13 oscillations, on the platform of which a measuring vibrating probe 60 is mounted, a former 14 connected to the second input of the second adder 2.

In each of the said parallel circuits, the control inputs of the keys 7 and 10 and the attenuators 9 and 11 are connected, respectively, for each circuit, the sensor-sensitive gates 15 and 16 to the output of the comparison unit 6.

The device works as follows.

A random signal from the output of the generator 1 passes through the second adder 2 to the input of the wideband filter 3 and the inputs of the bandpass filters -4-, the output of which is fed to the inputs of the dispersion meters 5 and either through the key 7 and the phase inverter 8 to the attenuator 9, or through the key 10 on attenuator 11. Attenuators 9 and 11 scale the channel signals, which are then fed to the adder 12. The signal from the output of the wideband filter 3 is also fed to the adder 12, in which the channel signals are either added to the random signal generated or subtracted out of him. The signal corrected in this way from adder 12 is supplied to the exciter 13 oscillations. Vibrator 14 starts to output a signal which is supplied to the adder 2. The adder 2 signal applied to the vibrator 14, is added to the signal generator 1. 5 meters dispersion measured power value in the passband of the filter 4 and then this signal is compared with the program signal, _etc. in block 6 comparison. The sign difference between the measured and programmed signals controls the operation of the keys through the signal-sensitive gates 15, 16 .7, 10. The voltage proportional to the magnitude of the mismatch is controlled by changing the transmission coefficient of the adjustable attenuators 9 or 11.

Thus, the introduction of a second adder and a wideband filter allows you to control the spectrum of random vibrations in a straight circuit by adding or subtracting channel signals with the generated signal coming from the measuring vibration transducer through a broadband filter, which provides an increase in the dynamic range and quality of dips in the formed spectrum.

Claims (1)

Claim A device for generating a spectrum of broadband random vibrations containing a white noise generator, parallel formation channels, each of which includes series-connected band-pass filter, a dispersion meter, a comparator, the second input of which is connected to the voltage source of the program, as well as parallel circuits connected to the output of the band-pass filter , one of which contains a sequence of 756244 6 controlled key and attenuator, while the other is a sequentially connected controlled key, a phase inverter controlled attenuator, and in each of these circuits · the control inputs of the key and the attenuator 5 are connected to the output of the comparator through the sign-sensitive valve, the adder, to which inputs the attenuators are connected connected to the output of an adder is a causative agent of coleoles, a measuring vibration transducer, characterized in that, in order to expand the types of spectra being formed, it is equipped with The second is the adder, the inputs of which are connected to the outputs of the white noise generator and the measuring vibroconverter, and the output to the inputs of rain filters, and the wideband filter whose input is connected to the output of the second adder, and the output of the first adder.