SU811339A1 - Device for pulse magnetization - Google Patents

Description

one

The invention relates to a technique for creating short-term high-power currents and magnetic fields and can be used in the magnetization of parts and assemblies, as well as a pulsed power supply for magnetic-pulse riveting, punching, etc. shock processes.

Pulse magnetization devices are known that contain a discharge capacitor, a rectifier, a control relay, an electronic switch on the ignitron with its ignition circuit, output terminals for connecting a magnetizing unit.

i.

The closest in technical essence is a device containing a power supply unit, an electronic key on a thyristor with a starting circuit, and a magnetizing inductor 2. A disadvantage of this device is the limited ability to adjust the parameters of the magnetizing field.

The object of the present invention is to enhance the ability to control the parameters of the magnetizing field.

The goal is achieved by the fact that, in a device for pulse magnetization containing a power supply unit, an electronic key on the thyristor with its triggering circuit and a magnetizing inductor.

An alternating current generator with adjustable frequency is used as the power supply unit, to the output of which a magnetizing inductor is connected via an electronic switch. The key start circuit is made in the form of a metering circuit of the number of pulses transmitted through a magnetizing inductor, containing an RC circuit and a series-connected separating diode and a resistor connected to the generator output, and an electronic switch switching circuit containing a control thyristor, RC circuit, and separating diodes , resistors and a control button, the anode of the control thyristor is connected to one point of the NS circuit of the dosage of the number of pulses, the other point of which is connected to the output of the generator, the cathode of the control thyristor connected

through the separation diode to the control electrode of the electronic key, and the control electrode of the control thyristor is connected through a resistor to one output of the alternator, and

To another output of the generator, through an isolating diode, one end of the electronic circuit is switched on to switch on the electronic key, which is shunted through the break contact of the control loop, and the other end of this

The NS circuit is connected to the cathode of the control thyristor through the closing contact of the button.

The drawing shows the electrical circuit of the device for pulse magnetization.

A magnetizing inductor 2 is connected to the output of an alternating current generator 1 with adjustable frequency through an electronic switch 3, for which a thyristor is used, which provides the passage of current pulses of positive polarity.

The thyristor 3 ignition circuit consists of a pulse number dosing circuit containing a resistor 4, a separating diode 5, a capacitor 6 and a resistor 7, and an electronic switch on circuit comprising a control thyristor 8, a diode 9, a resistor 10, a separating diode 11, a resistor 12, the capacitor 13 and the control button 14. The resistor 15 bypasses the thyristor 3 ignition circuit.

The device works as follows.

When generator 1 is turned on, sine-wave pulses are applied to the device. Since the thyristor 3 is closed, the magnetizing inductor 2 is disconnected from the generator circuit, and the capacitor 6 is charged through the resistor 4, the separation diode 5 and the resistor 7 with positive pulses to the peak output voltage produced by the generator 1.

When the button 14 is pressed, the turn-on circuit of the control thyristor 8 closes, and, if the turn-on time coincides with the arrival of a negative polarity pulse, the capacitor 13 begins to charge through the resistor 10, the resistance section of the control electrode is the cathode of the control thyristor 8, the closed contacts of button 14 , separation diode 11 and resistor 12.

If the activation time of the button 14 coincides with the arrival of a positive polarity pulse, the charging circuit of the capacitor 13 will be opened by the separation diode 11, and the capacitor 13 will start charging only with the arrival of the next, i.e., negative, half-cycle,

At the moment of passage of current through the control electrode – cathode section, the thyristor 8 is opened and maintained in the open state due to the discharge of the capacitor 6 through the thyristor 8, diode 9, resistor 15, control electrode – cathode section of the thyristor 3, magnetizing inductor resistance 2 and resistor 7. The thyristor 3 cannot open, since the negative half-period maintains a blocking negative voltage at its anode.

At the moment of arrival of the positive half cycle, the current of the thyristor 8, determined by the resistor 4, increases to the ignition current of the thyristor 3, and the thyristor 3 opens.

At the time of opening the thyristor 3, the current passes completely through the magnetizing inductor 2, creating a magnetic field in it.

The parameters of the capacitor 6 and resistors 7 and 15 are selected so that the discharge time of the capacitor 6 is not less than the duration of one half-cycle of the frequency of the alternator or

corresponded to the duration of several half-periods. If the parameters of the RC dosing circuit for the number of pulses are chosen greater than for a single pulse, the control thyristor 8 in the next negative half-period will remain open due to the discharge of the capacitor 6 through the resistor 7 and the section of the control electrode-cathode of the thyristor 3 and magnetizing inductor 2. Resistor 15 multiple

reduces the resistance of the control electrode - cathode of the thyristor 3, but its parameters are chosen in such a way that its influence is insignificant during this period of time.

After the final discharge of the capacitor 6, the control thyristor 8 is closed, and the capacitor 13 by this time is usually charged to full peak voltage, and the current through the turn-on circuit of the thyristor 8 no longer passes, although button 14 is pressed for a long time.

To pass a new current pulse through inductor 2, a button 14 is necessary.

let go. After releasing the button 14, its normally closed contacts discharge the capacitor 13 through the resistor 12, thus preparing the circuit for a new connection, and the capacitor 6 is charged back into positive half-periods to a peak voltage, and the installation is ready for operation.

The separation diode 9 is required to open the thyristor 8 so that when the button 14 is pressed, the current passes only through the resistor 10 and the section of the control electrode-cathode of the control thyristor 8 and then to the charge of the capacitor 13 through the resistor 12 and diode 11.

The thyristor 3 ignition angle is selected with the values of resistors 4 and 15. With powerful power thyristors and a small ignition angle, the resistor 15 may be completely absent.

Thus, the magnetization device connects the magnetizing inductor 2 to the calculated number of positive half cycles when the button 14 is pressed once.

When using this device for riveting or shtampovki to create a shock high-speed field, the frequency of the generator is chosen higher, and the parameters of the scheme increases the angle

ignition thyristor key.

Claims (2)

1. USSR author's certificate number 427402, cl. H 01 F 13/00, 1975. 2. Journal "Instruments and equipment of experiment No. 4, 1972, p. 203-205 (prototype).