SU36958A1 - Max dc switch - Google Patents

Description

There are already known maximum DC switches, the mobile system of which is directly connected to the cortex of a magnet, equipped with a winding connected to the main current circuit, and a voltage winding. The armature, together with the fixed system, is held in the working position by a voltage winding, counteracting the force of the switching spring. The main current winding is designed so that it counteracts the voltage winding and, with the onpressed power of the main current, reduces the magnetic power flux generated by the voltage winding to such an extent that the holding force of the magnet is overcome by the deflecting force of the switching off spring. In such switches, with a sudden increase in the main current and caused by this sudden decrease in the magnetic flux of the winding voltage, an electromotive force arises in the latter, which tends to keep the magnetic flux present (624)

its value, which extremely increases the off time; the latter is sometimes so great that magnetization occurs, and measles cannot be swept away at all. In advanced switches of the same type, in order to eliminate the aforementioned drawbacks, the core of the voltage coil is designed so that for the power flow of this coil, besides the magnetic path closed through the measles, there is a second magnetic path.

The present invention relates to a device of such a switch and is in its constructive implementation.

In FIG. 1 and 2 schematically depict two different forms of the proposed switch.

The mai switch wire shown in FIG. 1, is made in the form of an H-shaped core a, carrying on the middle core a voltage winding with and closed from the side of one

a pair of poles by a cow d, and from the side of another pair of poles by a magnetic shunt /, in the form of a rom separated from the magnetic duct by an adjustable air gap e. The magnetic shunt / superimposed included in the circuit of the glive current is a winding g. Anchor d is pivotally attached to the lower pole of the right side of the magnetic circuit and is rigidly connected to the moving system A of the switch pulled back to the off position by the spring. The switch is equipped with arcing horns I and t and a coil and a magnetic blow. The magnetic flux excited by the voltage winding goes, respectively, on the magnetic conductivity of both magnetic circuits and the air supply e, partly through measles, and partly via rf /. As long as the main current winding g is not energized or the power of the current passing through it does not exceed a certain definite limit, measur d, counteracting the force of the opening spring /, keeps the switch in the on position. The main current winding g is TEK, that the magnetic flux excited by it, which partially closes through the winding core b through the measles d, in the core b has a direction that coincides with the direction of the magnetic flux induced by the winding c, and the opposite d direction in the core. Therefore, as the current increases and, consequently, the magnetic flux of the winding g, the magnetic flux is closed through the core b of the excitation winding, the magnetic flux will increase, while the magnetic flux in the core d will decrease. The dimensions of the core b are selected so that it is highly saturated when the current passing through the winding g reaches its maximum allowable value.

With a further increase in the current in the circuit protected by the switch, the magnetic flux in the core d will decrease to such an extent that the spring force will be sufficient to tear off the coil | l d together with the moving system from the core a and thereby unplug the contacts A and L.

If the main current rises very quickly, then the voltage winding in RELATED magnetic flux, caused by this rapid increase and trying to close through the core b, acts as a reactive coil. Therefore, most of the additional magnetic flux, which in this case is excited by the main current winding, is closed through the pin d, and not through the core b, despite the unsaturated state of the latter. Since this additional flow, as already mentioned, in the cortex d will be directed towards the flow induced by the coil c, the resulting flow in the cortex d will decrease so much that the spring / will turn off freely before the core b reaches the saturation state.

A short-circuited winding may be placed on the core B to further accelerate the deactivation. The cross-section of the frame / is chosen so that even with the highest short-circuit current in the winding g, the poles of the core a can not be magnetized, and if this happens, it is so insignificant that the core sticking cannot take place. Likewise, measles is retracted if, for some reason, the voltage winding is turned off, and those pass through the main current winding. Any value. Setting the switch to a certain current strength at which it should operate is made by changing the air gap e rm /.

In the modified device (Fig. 2), the magnetic core is made in the form of a U-shaped core, which closes the moving system through the pin d and carries the excitation winding c, c .. The magnetic shunt carrying the main current winding g is located between the voltage winding and the core. In the same way as in the device according to r. 1, a short-circuited winding o can be placed on the core of the field winding.

In the case of using a switch for very large currents, it is advisable to turn the winding g not directly into the dissection of wires, but by means of a shunt. So that with a sudden increase in the current in the network, an increase in the current in this winding, due to its ductive resistance, does not occur more slowly than in the other branch, the latter includes a reactive cable, the inductive resistance of which at least should be equal to the inductive resistance of the main winding current.

If its inductive impedance is chosen greater than the inductive impedance of the main current winding, in the latter the current increases sooner than it corresponds to the overall increase in current, and thus also causes an acceleration of deactivation.

The subject of the patent.

Claims (5)

1. The maximum DC switch, the movable system of which is held in the on position by the magnetic power flux of the winding of the excitation and turned off through the main current winding acting on this flux, in which the switch for the power flux of the excitation winding provides, besides the magnetic path, closing through the bore , the second magnetic path, characterized in that the said second path is formed by a magnetic shunt in the form of a frame, carrying the main current winding, separated by an air from the magnetic conductor gaps, and this ram is turned on so that the magnetic flux excited by it closes partially through the core of the excitation winding, communicates with the magnetic flux excited by it, so that when the current rises rapidly, the main winding pro duces i inductive action, weakening the current Measles the flow of power in order to accelerate the onset of automatic shutdown. 2. The form of making the maximum switch according to claim 1, characterized in that a short-closed winding is placed on the magnetic core, which serves to accelerate the action of the switch. 3. The form of the maximum switch on PP. 1 and 2, characterized in that the magnetic conductor consists of a U-shaped core, which carries an excitation winding on the middle core and closes on one side of a pair of poles through the bore of a moving system, and on the other side of the field; shunt (fig. 1). 4. The form of the maximum switch on PP. 1 and 2, characterized in that the magnetic core consists of an E-erase core, which closes the moving system through the bark and carries an excitation winding, the magnetic shunt carrying the main current winding being located between the voltage winding and the core (FNG. 2). 5. The form of the maximum switch on. pp 3 and 4, characterized in that a short-circuited winding is located on the core of the field winding. ig. one 0 GL  V t   t 1 o f -BUT WTT sr ef Fig 2 ll  1 t