SU1206843A1 - Device for controlling d.c.electromagnet - Google Patents

Description

The invention relates to non-contact electrical circuit control systems and is specifically designed to control high-speed electromagnets.

The purpose of the invention is to increase the frequency of operation of an electromagnet by providing a stable switching mode of controlled keys.

Fig. 1 shows the electrical circuit of the device; Fig. 2 shows diagrams of the input control voltage and current, passage w, its electromagnet.

Input amplifier output

1connect, for example, through „optocoupler

2k to the amplifier 3 of the holding key 4 and to the input of the driver 5.

The output of the driver 5 is connected to the input of the starting key 6, performed, for example, on an optocoupler thyristor connected to the positive pole of the forcing voltage + Ucp. Parallel to the key 6 is included switching choke 7, connected to the capacitor 8.

A resistor 9 connected to the cathode, separating diode 10 and the winding of the electromagnet 11 is connected to the point of connection of the key 6 and the capacitor 8.

The positive pole of the source of the confining voltage is connected to the anode of the diode 10, the cathode of the diode 12. connected to the negative pole of the forcing voltage source Uep, and the anode of diode 13 - with the winding of electromagnet II and the anode of diode 12

A common point of the winding of the electromagnet 11, the anode of the diode 12, the anode of the diode 13 is connected to the output of the discharge circuit 14, which consists of a diode, a resistor and a capacitor, which protects the key 4 from switching voltage surges. A negative bus voltage holding voltage is connected to a holding key 4 connected to the cathode of the diode 13 and to another output of the discharge circuit 14.

Input amplifier 1, driver 5 is connected to a power source. The amplifier 3 of the holding key 4 is connected to a power source and the negative bus of which is connected to Uy.

To explain the operation of the device in FIG. 2a is an input voltage diagram, and

06843

FIG. 26 is a diagram of the current flowing through the winding of the electromagnet at the time of the forced connection and transition to the hold mode, c, and also the duration of the operation of 1 switching circuit;

thyristor 6 - choke 7 - capacitor 8.

The device works as follows.

10 way;

When the input voltage is received at the input of the amplifier 1, AND in accordance with the diagram shown in FIG. 2a is included opt

15 ron 2 and the amplifier 3 generates a control signal for unlocking the holding key 4. At the same time, the driver 5 synchronously with the leading edge of the input signal produces a start signal for opening the thyristor 6.

Through the choke 7, the precharged capacitor 8 is discharged to the thyristor 6, thus creating

25 with the circuit of the forced switching on of the electromagnet along the circuit: + Ucp, thyristor 6, resistor 9, electromagnet 11, diode 12, and. When the negative half-wave of the current passes through the thyristor 6 as a result of the recharging of the capacitor 8, the thyristor 6 is closed, the capacitor 8 is charged before the source voltage Ucp and in the presence of the input voltage Ugx at the input of the amplifier 1 the boost current according to the diagram shown in FIG. 26, is reduced to the magnitude of the holding current 1 along the circuit: + Uyj diode 10, electromagnet 11, diode 13 holding key 4, Uyji. If the duration of the control signal at the input of amplifier 1 is less than the duration of the ip transient process in the switching circuit, then the current in the winding

5 electromagnet 1 I is reduced to zero, since the holding key 4 at this time will be already closed.

In the proposed device, controllable keys — start and hold keys can be executed on transistors, single-operation and two-operation (lockable) thyristors, while the controllable inputs: start key and hold-down amplifier

55 keys can be connected

with the help of pulsed and low-frequency transformers or with the aid of a magnetodiode. - a solenoid, however;

thirty

35

the connection of functional units in this case should be performed in the proposed sequence.

. As the input amplifier 1, amplifier 3, shaper 5 can be used chips of known series,

A device made according to the proposed scheme using optocoupler 206843

of thyristors of the type TO-10-10, provides the maximum frequency of operation of the electromagnet up to 300 Hz at forcing and holding voltages, respectively, 140-1 80 and: 9-12 V, Electromagnet parameters: inductance 0.0810.02 Hz, stroke of 1.25 mm, forcing and holding currents of 3.5 and 0.6 A. -s

4iB

1- n

 U -v -v

- -o.V

Phi

Claims (1)

DEVICE FOR CONTROLLING A DC ELECTROMAGNET, containing a starting key, holding a key, a diode, a switching circuit including a choke and a capacitor, a resistor, amplifiers, control signal drivers of a starting and holding key, a protective circuit of the holding key, including a series-connected diode and a diode and capacitor shunted by a resistor, leads for connecting an electromagnet winding, leads for connecting a boost voltage source, and leads for connecting a power source live voltage, and one of the terminals for connecting the boost voltage source through a series-connected starting switch, shunted by a switching circuit, and the resistor is connected to one of the terminals for connecting the electromagnet winding, which is connected through a diode to one of the terminals for connecting the holding voltage source, one from the terminals of the holding key is connected to another terminal for connecting the source of the boost voltage and the resistor of the protective circuit of the holding key, the outputs of the amplifier Formers control signals' start-up and retaining keys are connected to inputs of said switches of m and l - sistent _with the fact that, in order; 9 to increase the purity of operation by ensuring a stable switching mode, the second and third diodes are introduced into it, and the other terminal for connecting the boost voltage source through the second diode is connected to another terminal for connecting the electromagnet winding, which is connected through the third diode to another terminal of the holding key, the diode the protective circuit of the holding key is connected to the connection point of the second and third diodes. SU „1206843