SU20721A1 - Electromagnetic automatic maximum DC switch - Google Patents

Description

The principle of the electromagnetic automatic maximum current switches of most European and American companies (GEC, AEG, Westingshouse, Metrovick, SSWH, etc.) is based on instantaneous demagnetization of the magnetic flux generated from an external auxiliary current source and holding measles in the on position, passage through the switch and exceeded the permissible limits by the current, after which the contact is broken by means of a strong spring provided for this purpose. A solenoid capable of overcoming the resistance of the mentioned spring is used to turn on the switch.

In the proposed circuit breaker, for the purpose of shutdown, it is intended to directly use the main current flow, as a result of which it becomes possible to abolish the switching spring. In addition, the switching coil is located on the switch itself, why should

no need for a strong solenoid to turn on the latter.

Depicted on the schematic drawing of the specified electromagnetic automatic maximum switch consists of a magnet a W-shaped and the core 5, swinging on an axis against the middle core. Mechanically breaking contact with a bark is connected with (magnetic extinguishing on horns is carried out in the usual way and is not jocazano in the drawing). The following windings are placed on each of the three cores of the W-shaped magnet: on the middle coil e, permanently included in the auxiliary current circuit and designed to hold the swinging core b in its extreme positions corresponding to the on and off of the main circuit.

On the two extreme cores are located: ia core / -including coil /, included in the same way as Coil e, in the auxiliary current circuit and acting when switched on in accordance with it; on the core of the same III-coil d,

connected in series in the switching circuit and acting against the coil.

In the closed position, the switch is held by the flow of the coil e, which presses the measles to the core /. This stream, meeting a large air gap on the way to the core of the JII, does not pass through it. Winding the main current on the core 111 with increasing current gives a flux demagnetizing the core / and directed to the core P in the same direction as the flux holding the coils e. At the critical value of the main current, the flux passing through the core I will be fully demagnetized, the main current flow passing through the core III, with a force of force against the specified core, as a result of which contact is opened and the main current circuit is interrupted.

The process of switching on proceeds in a similar way: when the auxiliary current is switched on in the holding and including coils, the flow created by the coil f is directed to the core III against the main flow, as a result of which they demagnetize each other; on the core, however / both flows have a consonant direction, as a result of which the measles should assume the switching position.

In the event of a current failure, the measles was not in the neutral swing state, a weak spring 9 was applied, keeping it in the off position.

The subject of the patent.

Electromagnetic automatic maximum DC switch, consisting of a W-shaped electromagnet, in front of the middle core of which there is an axis with a core swinging on it, characterized by the coil e located on said middle core II, which is permanently connected to the auxiliary circuit. for keeping the swinging core b mechanically connected with the breaking contact with the circuit to be switched off, in its extreme positions corresponding to the switching on and off of this circuit, for In the absence of current, the measles b are not in a neutral swinging position, a weak spring d is used, on the same two cores on the same I there is an enabling coil f, connected in the same way as coil e to the auxiliary current circuit and operating switching on in accordance with coil e, and on the other III - coil d, is connected in series to the circuit to be turned off and acting against coil f.