SU1292046A1 - Control device for electromagnet - Google Patents

Abstract

The invention relates to the field of electrical engineering, namely electric drives, and can be used to control drive electromagnets of impulse action systems, for example presses, hammers, sources of seismic vibrations, etc. The aim of the invention is to improve: the reliability of the operation of the device. To turn on the electromagnet 1, a storage capacitor 10 is used, which is precharged through a resistor 15. The proposed device ensures the duration of the current pulse in the electromagnet winding due to the synchronization of the onset of this pulse with the beginning of the positive half-wave voltage of the power supply. The synchronizing pulses are produced by the pulse shaper, which includes a resistor 16, a zener diode 17, a diode 18 and a capacitor 19. When the button 9 is closed, the discharge of the capacitor 19 does not start immediately, but after the first synchronizing impulse 8 arrives at the control electrode. 1 il. with

Description

The invention relates to electrical engineering, in particular to electric drives, and can be used to control drive electromagnets of impulse action systems, such as presses, hammers, source of seismic vibrations, etc.

The purpose of the invention is to increase the operating function of the device.

The drawing shows the electrical circuit of the electromagnet control device.

The device contains an electromagnet winding 1 connected to a power source through a group of thyristors 2-4 whose control electrodes are connected through Their zener diode 11 to the first zener diode 11 through auxiliary thyristor 8, start button 9, first capacitor 10 shunted by the first zener diode.

Thyristor control transition circuits through current-limiting resistors are shunted by series-connected variable 12 and limiting 13 resistors. The charge circuit of the capacitor 10 includes the first diode 14, the zener diode 11 and the charging resistor 15. The synchronizing voltage pulse generator containing the ballast resistor 16, the second zener diode 17, the second diode 18 and the second capacitor 19 are used to control the auxiliary thyristor. The electromagnet winding is shunting a magnetic field suppression circuit consisting of a diode 20 and a resistor 21.

The principle of operation of the device is considered on the example of a half-wave three-phase controlled rectifier.

In the original state, the capacitor 10 is charged until the voltage of stabilization of the Zener diode 11 across the circuit: one power supply terminal, charging resistor 15, first diode 14, closed contacts of button 9, capacitor 10, electromagnet winding 1, second power supply terminal. Thyristors 2 - 4 are locked, as the auxiliary thyristor 8 is locked due to the absence of voltage at its anode.

At the moments of transition of the source voltage through zero, the positive synchronizing voltage pulses are supplied from the synchronization pulse shaper consisting of elements 16-19 to the control electrode

20

25

five

thirty

35

40

45

50

55 auxiliary thyristor 8, and their amplitude is insufficient to unlock the thyristors. 2-4.

When the start button 9 is pressed, a circuit is created: a capacitor 10, a start button 9, auxiliary thyristor 8, Current limiting resistors 5-7, rectifying electrodes and cathodes of thyristors 2-4.

At the time of the occurrence of the first positive timing pulse on the control electrode of the auxiliary thyristor 8, it opens, and the capacitor 10 is charged through the control junctions of the thyristors 2-4. At the same time, the power thyristors 2-4 are unlocked only at the moment when the positive half-wave of the power supply starts to start after the start button is pressed. On the winding of the electromagnet 1 current flows, causing it to trigger. At the end of the discharge of the capacitor 10, the thyristors are locked.

The residual energy stored in the magnetic circuit of the electromagnet is dissipated in the circuit: the winding of the electromagnet 1j diode 20, the resistor 21.

When button 9 returns to its original state, the charge of capacitor 10 occurs. The cycle can be repeated.

By varying the resistance value of the resistor 12, it is possible to regulate the time of current flow through the winding of the electromagnet 1 and thus the energy of the working stroke of the machine driven by an electromagnet.

Thus, the proposed device favorably differs from the known one, since it ensures the constancy of the current pulse duration in the electromagnet winding by synchronizing the onset of this pulse with the start of the positive half-wave voltage of the power supply and by stabilizing the discharge current time of the capacitor through thyristor control transitions. This ensures the stability of the force and mechanical operation of the electromagnet, reduces the required duration of the current pulse in the winding of the electromagnet, which reduces the wear of its elements and facilitates the thermal mode of the winding,

When adjusting the force and mechanical operation of an electromagnet, the amplitude of the current through the control transitions of the thyristors does not change, which ensures

It improves the reliability of their operation. And the device as a whole,

Claims (1)

 Invention Formula A device for controlling an electromagnet containing a controlled rectifier with a cathode group of thyristors, a capacitor, a diode, a variable resistor, three current-limiting resistors, leads for connecting an electromagnet winding, outputs for connecting a power source and a start button with a switching contact group, thyristor anodes are connected to one of the terminals for connecting the power source, the thyristor cathodes are connected to one of the terminals for connecting the winding of the electromagnet, the other terminal of which is connected to another By means of a power supply terminal, the thyristor control electrodes are connected to each other through current limiting resistors and connected to the first output of the variable resistor, one of the capacitor plates is connected to the thyristor cathodes, and the other is connected to a moving contact of the switching contact group Editor A.Vorovich Compiled by A.Karett1kov Tehred A. Kravchuk Proofreader V, But ha Order 277/51 Circulation 699 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 fO at 20 A start button, one of the fixed contacts of which is connected to the cathode of the diode, is characterized in that, in order to increase the reliability of the device, an auxiliary thyristor, a second capacitor, two zener diodes, a ballast and a charging resistors and a second diode are inserted into it, and the anode of the first the diode is connected to the cathode of the first Zener diode and through a ballast resistor to an output for connecting the power source and one of the diodes of the charging resistor, the other output of which is connected to the cathode of the second Zener diode and a capacitor to the cathode of the second diode and the control electrode of the auxiliary thyristor, the anode of the second diode and the first and second zener diodes are interconnected and connected to the cathodes of the rectifier thyristors, the cathode of the auxiliary thyristor is connected to the first output of the variable resistor, the second output of which is connected to the cathodes of the thyristor a torch rectifier, the anode of the auxiliary thyristor is connected to another fixed contact of the switching contact group of the start.