RU2403644C1 - Single action switch - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: switch accommodates a case (1), a heater (3) with an external core (2), a drive actuating the core (4) with a spring (5), a cross frame (6), a fuse strip (7) and a normally open terminal pair (8). When applying a voltage on a heater winding (3), the cross frame (6) closes the terminal pair (8) to form a circuit: power supply (an accumulator), terminal pair (8) and fuse strip (7). Driven by a short-circuit current generated by a remaining charge of the disconnected accumulator, the fuse strip blows out, and the accumulator is disconnected before discharged completely.

EFFECT: junction resistance decrease of the normally closed contacts, design simplification, downsizing and weight reduction.

1 dwg

Description

The switch belongs to the field of electrical engineering and can be used for one-time switching of electrical circuits in various operating conditions, including zero gravity and vacuum, with significant mechanical loads.

Known polarized bi-stable relays, operable under similar conditions, for example, of the RPS type (1), are sealed relays filled with inert gas, designed for small currents and voltages.

Sealing relays of increased power complicates the design scheme, significantly increases the size and weight.

Leaky electromechanical polarized bi-stable relays of the REP type (REP 32-280, REP 33-200) are known, which provide switching currents of tens of amperes (2, 3), but they have significant dimensions and weight (due to the presence of an electromagnetic drive). In addition, in a number of specific cases, multiple switching is not required, but one is enough. For example, in power supply circuits of spacecraft to turn off a degrading battery (banks) and organize a bypass circuit on the corresponding serial element of the battery.

One-time small-sized short-circuit short-circuit switches (4, 5, 6) are known, in which the normally open contacts are closed by a copper movable contact, previously soldered to one of the two terminals inside the heater. If it is necessary to activate the heater winding, voltage is applied, by command (4, 5) or in automatic mode (6) when heating, the solder holding the movable contact melts, the contact moves under the influence of a spring and closes the circuit. The disadvantages of such a design scheme include a limited scope - it cannot be used as a switch.

The closest in technical essence is a one-time switch (7), which includes one pair of normally closed and one pair of normally open contacts. After applying voltage to the control winding of the switch and melting the holding solder, the spring moves the crosshead with movable contacts and switching occurs.

During the switching process, the integrity of the internal circuit of the battery must be maintained, therefore, a bypass circuit must first be arranged around the degrading battery, i.e. First, it is necessary to close the normally-open contacts, and then to open the normally-closed contacts, which ensures that the battery is disconnected.

The disadvantages of this switch include increased contact resistance of normally-closed contacts. When using such switches as part of the battery of batteries, all normally closed pairs of contacts (according to the number of switches with batteries) are connected in series, therefore this circuit leads to a noticeable decrease in the output voltage of the battery.

In addition, when the “dry” contacts are opened, at high currents, an arc can form, to extinguish which “magnetic blasting” is used, which complicates the design of the switch, increases its dimensions and weight.

The purpose of this technical solution (drawing) is to reduce the transition resistance of normally-closed contacts, simplify the design, reduce the size and weight. This goal is achieved by the fact that only one pair of (normally-closed) “dry” contacts (8) is built into the housing (1), and the second pair is replaced by a fuse (7).

The actuator for closing the contacts is a core (4) with a spring (5), previously soldered into a heater (3) with an external core (2). When voltage is applied to the heater winding, the solder melts and the core with the spring moves the traverse (6) with movable contacts, normally open contacts close, a circuit is organized bypassing the degrading battery and a closed circuit is formed according to the scheme: battery-closed “dry” contacts - fuse . Under the influence of a short circuit current from the remaining battery charge, the fuse melts and the battery turns off. To avoid a malfunction in the output voltage of the battery and the power of the equipment connected to it, the degrading battery is not brought to a full discharge, but is turned off earlier, even if it has enough energy to destroy the fuse by a short circuit current. A sufficient length of the thread of the fusible insert and a relatively low voltage of the battery eliminates the likelihood of an arc, therefore, special arcing measures are not required.

Literature

1. Thomas R.K. Switching devices. M .: Radio and communications, 1984.

2. Chunikhin A.A. Electrical apparatus. M .: Energoatomizdat, 1988.

3. GOST B 221-70.

4. Certificate for utility model No. 5287 / Disposable short-circuit breaker / Miryutov A.V., Stanko E.D., Tsyganov O.A. Bull. No. 10, 1997.

5. The certificate of the Russian Federation for utility model No. 10286 / Short-circuit breaker of one-time action / Tsyganov OA, Miryutov AV Bull. No. 6, 1999.

6. Certificate of the Russian Federation for utility model No. 10940 / One-time short-circuit / Mirutov A.V., Tsyganov O.A., Heints E.R. Bull. No. 8, 1999.

7. RF patent for utility model No. 80708 / One-time operation switch. Miryutov A.V., Fomin K.N., Abakumova G.V., Susenkova K.I., Kashin P.I. Bull. No. 5 of 2009

Claims (1)

The one-time switch contains one normally closed circuit and one pair of normally open "dry" contacts, the closure of which occurs after applying voltage to the coil of the drive heater, characterized in that the normally closed circuit uses a fuse as contacts, which breaks after the normally open contacts are closed short circuit current from the remaining charge of the disconnected battery.