SU1122372A1 - Electromagnetic vibration exciter - Google Patents

Abstract

ELECTROMAGNETIC OSCILLATOR OF VIBRATIONS, containing a headset, connected to it by an elastic coupling and shorting it through the air gap of the measles, excitation coil with a resistance connected in series to its input, a load circuit of series-connected inductance and a controlled diode, characterized in that the purpose of increasing the stability of the amplitude of oscillations in a wide range of loads, the resistance is made reactive with a negative impedance, and the load circuit is connected in parallel Coils are driving. ABOUT)

Description

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SA) The invention relates to instrument making and can be used in a vibration technique for exciting vibrations of a working member of vibration machines. A known electromagnetic vibration exciter comprising a U-shaped core connected to it by an elastic measles coupling and an electromagnetic oscillation excitation circuit l. The disadvantage of this device is the closure of the DC component to the network, the low power factor due to the large amount of DC current entering the network, and the impossibility of adjusting the vibration exciter to the required amplitude of oscillations. The closest to the invention to the technical essence is the electromagnetic exciter of oscillations, which contains a U-shaped magnetic circuit. an elastic connection connected to it and a measles closing it through an air gap, a power supply coil with a resistance connected in series to its output and a load circuit from a series-connected inductance and a controlled spring 2. A disadvantage of the known devices is that the oscillation amplitude when idling significantly exceeds the magnitude of the oscillation amplitude under load and strongly depends on the magnitude of the load. The aim of the invention is to increase the stability of the amplitude of oscillations, in a wide range of load variations. The goal is achieved by the fact that in an electromagnetic exciter containing a magnetic circuit connected to it by an elastic coupling and closing it through the air gap, the excitation coil is connected afterwards to its input; / resistance, load circuit of series-connected inductance and controlled diode, resistance is thrown out reactive, with negative impedance, and the load circuit is Connected parallel to the excitation coil. The drawing shows the scheme of the proposed vibration exciter. The electromagnetic exciter consists of a U shaped magnetic circuit 1, a movable core 2, an elastic system 3 and an electrical circuit for exciting oscillations consisting of an excitation coil 4 attached to a magnetic conductor, a load circuit consisting of an inductance 5 and a controlled diode 6 and connected to the ends of the excitation coil, resistance with a negative impedance 7, for example, a capacitor of the appropriate e -1 connected between the network and the coil. The capacitor 7 and the excitation coil 4 form the first circuit, closed to the network, and the load circuit and the excitation coil form the second circuit. Electromagnetic pathogen works in the following way. A sinusoidal voltage, U, s noji, applied to the network terminals of the circuit, causes an alternating current in the primary circuit. In the second circuit, along with a variable 1m, a constant current is generated that flows around the excitation coil. AC and DC currents in the excitation coil create a total magnetic flux that varies according to the law, -05ot constant component of the magnetic flux, amplitude value of the maximum component of the magnetic flux, the circular frequency of the mains voltage. This magnetic flux creates a perturbing force coscjt + P cosZcjt, P P -f, which is the constant component of the perturbing force, ajv, the linear values of the first and second harmonics. The stiffness of the elastic system is tuned close to the resonance with the fundamental frequency, therefore, the oscillations of the core 2 are derived from the frequency of the first harmonic. Stabilization of the amplitude of oscillations and the opti-gizai and operating mode is achieved by installing a network with a network and a cathode of excitation with a help of negative ilterans, for example

condenser. An increase in the technological load causes an increase in the magnitude of the mains current. An increase in the current intensity increases the voltage across the capacitor plates, as a result of which the voltage at the ends of the coil increases and the voltage increases. And the network voltage is And does not depend on the technological load.

The first harmonic of the force of gi is approximately proportional to the square of Uv. Therefore, in the proposed vibration exciter, with an increase in the technological load, there is an intensive increase in the thrust force, which prevents a decrease in the amplitude of oscillations, i.e. stabilizing it.

Stabilizing the amplitude of oscillations in a wide range of load variations improves transportation performance and metering accuracy of bulk materials, and removing one of the windings saves copper consumption, which all together contribute to obtaining a large economic effect during the implementation of the proposed invention.

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Claims (1)

ELECTROMAGNETIC EXCITER OF OSCILLATIONS, containing a magnetic circuit connected to it by an elastic link and closing it through an air gap, an armature coil with a resistance connected in series to its input, a load circuit made of inductors connected in series and a controlled diode, characterized in that, in order to increase the stability of the amplitude oscillations in a wide range of load changes, the resistance is made reactive with negative impedance, and the load circuit is connected in parallel with the coil in excitations. > 2372 1,112