SU1500389A1 - Electromagnetic vibration exciter - Google Patents

Abstract

The invention relates to a vibration technique and is intended to produce sinusoidal vibration in a wide frequency range. The purpose of the invention is to improve the accuracy of reproduction of a given amplitude and shape of vibration and the expansion of the frequency range of vibrations. The electromagnetic exciter contains two electromagnets 1 and 2, measles 3, alternating current coils 4 and 5, and bias coils 6 and 7, two induction sensors 8 and 9 connected in series, the proximity sensor 10 of the core, the first 11 and the second 12 switches, element 13 compare , a bias current control unit 14, a source of a master sinusoidal signal, a frequency master 16, a sinusoid driver 17, a power amplifier 18 and an amplitude sensor 19. 1 il.

Description

01

The invention relates to a vibration technique and is intended to produce sinusoidal vibration in the frequency range from fractions of a hertz to several hundred hertz.

The purpose of the invention is to show the accuracy of reproduction of a given amplitude and shape of vibration and the expansion of the frequency range of vibrations.

The drawing shows the functional diagram of the device.

The electromagnetic vibration exciter contains two electromagnets 1 and 2, between which the measles 3 are located on an elastic suspension with gaps, Coils A and 5 of alternating current and coil 6, and 7 bias are located on the central magnetic conductors of the electromagnets of the electromagnets. In the gaps between the magnetic cores and the core there are two induction sensors 8 and 9 connected in series, made in the form of several turns of wire. A contactless displacement sensor 10, for example, of the inductive or capacitive type, is mounted up to the core. Sensors 8 and 9 are connected to the first input of the first switch 11, and sensor 10 to the second input of this switch and the input of the second switch 12. The output of the switch 11 is connected to the first input of the comparison element 13, the output of which is connected to the input of the bias current control unit 14 based on conventional amplifier. Unit 1A is connected to coils 6 and 7. As the setter, a source 15 of a master signal consisting of serially connected frequency setter 16 (for example, a controlled variable frequency pulse generator), a sinusoidator 17 and a power amplifier 18 is used. which are connected to windings 4 and 5. Amplitude sensor 19 represents a rectifier with a filter and an inverting amplifier, the voltage from the output of which determines the magnitude of the amplitude of the digital sinusoid of the source 15 of the specifying signal.

The device works as follows.

When alternating voltage is applied from the output of amplifier 18 to windings 4 and 5 and the bias current through coils 6 and 7, the core 3 vibrates. Normally, electromagnetic excite

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W 0 5 0 5 0 j

0

five

Is used when working in near-resonance mode. The device uses an automatic control system that has two modes of operation at position A and B of the switches.

In mode A, the position-based system ensures the effective operation of the exciter in the frequency range from fractions of a hertz to the frequency at which the phase distortion between the reference sinusoidal signal and the signal from the core position sensor is small. When the system is operating in mode A, measles 3 will make sinusoidal oscillations of the required amplitude in strict accordance with the specified reference signal. If the position of the core 3 (which is determined by the amplitude of the signal taken from the sensor 10) does not match the specified value, then the output of the comparison element 13 results in the error signal, which through block 14 will change the magnetization current so that the position of the core i corresponds to the specified one.

When the vibration exciter operates at frequencies close to the resonant ones, it drastically increases} the phase distortion and the operation of the system in mode A becomes ineffective. The signal from setting frequency 16 switches on mode B of switches 11 and 12. Two control loops are formed: in amplitude (inertial) and in shape (speed).

The amplitude control loop works as follows.

The frequency of the specified vibrations, as in mode A, is determined by the encoder 16. The constant voltage taken from sensor 19 determines the amplitude of the source sinusoid. If the oscillation amplitude of the core does not correspond to a given one (for example, more), after straightening and filtering, the increased voltage leads to a decrease in the signal at the output of the inverting amplifier. This signal determines the amplitude of the driving sine wave voltage. As it decreases, the core 3 oscillation amplitude decreases. The shape control loop contains induction sensors 8 and 9. In this case, the force effect on measles corresponds to the shape of the induction change in the gap, i.e. kosiyusodehde

Claims (1)

Electromagnetism is a vibration exciter comprising two electromagnets with alternating current windings each located on opposite sides of the core, a core displacement sensor, a source of the driving signal, different from THAT, in order to improve the accuracy and performance of a given amplitude and shape of vibration and expansion frequency range of vibrations, two induction sensors connected in series are inserted into it, installed in the gaps between the core and the magnetic conductor of each electromagnet, and a switch, a series-connected reference element, a bias current control unit and a bias winding located on the magnetic circuit of each electromagnet and interconnected in series, an amplitude sensor connected through the second switch with the output of the displacement sensor core and the output of the source level setting setting signal, while the other outputs of the induction sensors are connected to the housing and through the first switch with one input of the reference element, the other input The first switch is connected to the output of the core movement sensor, the other input of the comparison element is connected to the first output of the source of the master signal, the second and third outputs of which are connected to alternating current windings connected in parallel.