SU819843A1 - Magnetic starter control device - Google Patents

Description

(54) DEVICE FOR CONTROLLING A MAGNETIC START-UP

one

This invention relates to electrical engineering and can be used in remote control of switching devices.

A device for remote control of a magnetic starter is known, comprising a coil in the opposite direction shunted by a buffer diode and connected in series with a resistor and a capacitor, in parallel with which is a circuit consisting of a trip unit, starter and diode 1.

However, the device has low reliability due to the presence in the circuit of the opening contact, which breaks the starting current of the contactor roller and control contacts, closing the starting current, breaking the holding current of the magnetic starter.

Closest to the invention, the technical solution is a device containing a thyristor connected in series with the actuator coil and connected to the leads for connecting the line contacts of the magnetic actuator, and the thyristor control circuit through the current transformer is connected to one of the load contacts of the actuator 2.,

The drawbacks of this device are that in it the holding current is permanently closed through the thyristor and a current transformer is required to install the magnetic starter, which reduces the reliability and increases the size and cost of the device.

The aim of the invention is to increase the reliability of the device.

Claims (2)

This goal is achieved by the fact that in the device for controlling the magnetic starter, which contains the disconnecting contact of the Stop and thyristor button connected in series with the leads for connecting the magnetic starter coil and connected to the leads for connecting its linear contacts, the closing contact of the Start button connected through a resistor and a coupling diode to the anode and to the control electrode of the thyristor, to the anode of which a buffer diode is connected, connected in parallel to the leads for connecting a magnetic trigger coil He ate holding circuit consisting of a parallel capacitor and a discharge resistor, and a holding circuit closing contact point of connection "Start button with a resistor connected to a terminal for connecting the load contact magnetic actuator according to the line contact that is connected to the cathode of the thyristor. The drawing shows a circuit diagram of the device. The device contains a coil 1 connected via a button 2 Stop with a break contact and a thyristor 3 to terminals 4, 5 for connecting the line contacts of the magnetic actuator. The control electrode of the thyristor 3 through the button "Start 6c closing contacts, resistor 7 and the diode 8 of the connection is connected between the coil 1 and the anode of the thyristor 3. Button 6 is connected to the load contact 9 of the magnetic starter. The capacitor 10, shunted by the discharge resistor 11, is connected at one end to the load contact 9 and at the other end to the output of the coil 1. The main make contacts 9, 12, 13 switch the load 14, 15, 16 by connecting it to the terminals 4 , 5, 17. Diode 18 provides for the elimination of vibration with the crust drawn in. The device works as follows. When an alternating voltage is applied to the terminals 4, 5 and 17 and the button 6 is closed, a control current appears, the thyristor 3 opens and the starting current flowing through the coil 1 is detected, which is determined by the full-wave rectified voltage of the power supply. The parameters of the elements of the power supply circuit are selected in such a way that the rectified voltage is sufficient to force the electromagnet to operate. After the main contacts 9, 12 and 13 are closed, the thyristor control circuit 3 is bridged by contact 9, which causes the thyristor 3 to close, and a capacitor 10 is automatically connected to the power supply circuit of the coil 1, which limits the starting current to a value sufficient to keep the core in a relaxed state nii. The coil 1, after closing the main contacts 9, 12 and 13, is fed by half-wave voltage. Since the resistance of the coil 1 is much greater than the resistance of the diode 18, the reverse half-wave of the current passes, the coil 1 overcharges the capacitor 10. When the button 2 is pressed, the electromagnet’s bark disappears and the main contacts 9, 12 and 13 open. Thus, the scheme is prepared for the next inclusion. This device provides a high forcing factor, but unlike the prototype in this AC contactor, the main switching contacts automatically switch the power of the electromagnet from overvoltage at the time of start to reduced in the operating mode. Forcing is provided by the force contact 9 of the starter. This greatly increases the reliability of the device. The economic effect of using the device is achieved by reducing the operating costs of devices for controlling magnetic actuators. Claims Device for controlling a magnetic starter containing a break contact of the Stop button and a thyristor connected in series with the leads for connecting the magnetic starter coil and connected to the leads for connecting its line contacts, the closing contact of the Start button connected through a resistor and a communication diode to the anode and to the control electrode of the thyristor, to the anode of which a buffer diode is connected, is connected in parallel to the terminals for connecting the coil of the magnetic actuator, the holding circuit, This is from a parallel-connected capacitor and a discharge resistor, characterized in that, in order to increase the reliability of the device, the holding circuit and the connection point of the closing contact of the "Start with a resistor" button are connected to the output to connect the load contact of the magnetic starter corresponding to the line contact connected to thyristor cathode. Sources of information taken into account in the examination 1. England patent 1199660, cl. H 2 H, 1971. 2. Korpenko L. N. High-speed electrodynamic disconnect devices. M., “Energie, 1973, p. 27, fig. 2-7. 2 b / j .ff JO // /four /five J f IB ii KF