SU727997A1 - Device for reproducing given random vibrations on vibration table - Google Patents

Description

I

The invention relates to a measurement technique and can be used to study the spectrum of broadband random vibrations on vibrating tables.

A device for reproducing predetermined random vibrations on a brostender is known, comprising an adder, narrowband and wideband filters, attenuators and a generator connected by an output to an input of a broadband filter connected by an output to the inputs of a narrowband filter, the outputs of which through attenuators are connected to the inputs of an adder, which outputs through an amplifier designed to connect to shaker 1.

A disadvantage of this device is the design complexity and low reliability due to the presence of additional summation blocks.

The purpose of the invention is to simplify the design and increase reliability.

This is achieved by the fact that the device is equipped with a phase inverter, connected by an input to the output of a broadband filter, and an output to the corresponding input of an adder.

The drawing shows a block diagram of the device.

It contains an adder I, narrowband filters 2, 3 and broadband filter 4, attenuators 5, 6, amplifier 7, generator 8, connected by an output to the input of broadband filter 4 connected by an output to the inputs of narrowband filters 2, 3, the outputs of which through attenuators 5, 6 are connected to the inputs of the adder 1, the output of the KOTopoit) through the amplifier 7 is intended to be connected to a shaker (not shown in the drawing). The device is equipped with a phase inverter 9, connected by the input to the output of the broadband filter 4, and the output to the corresponding input of the adder 1.

The device works as follows.

Random signals from the output of the generator 8 through a wideband filter 4, which serves to form an average level of the modeling spectrum of random vibrations, arrive at the input of narrowband filters 2, 3. At the same time, random signals from the output of the wideband filter 4 through the phase inverter 9 post3.

are fed to the input of the adder 1. Provided that .. at the resonant frequency of any of the narrowband filters 2, 3 phase shift output, x. the signals relative to the input signals are equal to zero; the adder 1 will add or subtract signals of the average level from the output of the wideband filter 4 with the output signals of the narrowband filters 2, 3 1В depending on the transfer coefficients of attenuators 5, 6.

The attenuation coefficients for attenuators 5, 6 are 0-1. In this case, if, for example, the gain of any Of the narrowband filters 2, 3 is equal to K, then by adjusting the transfer coefficient of the corresponding attenuator 5, 6 in the range from O to 2 / K, you can get the dip of the required depth relative to the average level. The maximum depth of the dip will be when the attenuator gain factor is 5, 6 is approximately 1 / K.

With an attenuator transfer ratio of 2 / K to 1, a burst is formed relative to the average level. In all cases, the transfer ratio of phase inverter 9 is assumed to be equal to one. Thus, at the output of the adder 1, the generated signal can have both bursts and dips in the corresponding energy spectrum. Turning on the phase inverter 9. A wide band-band filter 4 - the adder 1 eliminates the second additional adder from the circuit and the necessity of switching the narrow-band filters 2, 3 with the phase inverters selectively included in each of the failing channels, which greatly simplifies the device

727997

and increases the reliability of his work. Next, the signal from the output of the adder 1 through the amplifier 7 is fed to the shaker. The number of narrow band filters depends on the task.

The proposed device due to the simplicity of the circuit design has higher technical and economic indicators, which ultimately reduces the cost of testing and increases their efficiency.

Claims (1)

1 .. USSR Author's Certificate No. 393631, cl. G 01 M 7/00, 1970 (prototype). / C v rostendu