SU143928A1 - Magnetic relay - Google Patents

Description

The proposed magnetic relay is of a known type of switching devices, designed for contactless telemechanical systems and made according to the type of magnetic amplifier with a core of a material with a rectangular hysteresis loop.

Like the known devices in the device constituting the invention, on the indicated core there are three windings, one control winding and two field windings connected and fed through diodes from the included transformer windings.

The peculiarity of the switching device is that the relay effect in it is achieved not through feedback and constant biasing, as is the case in known devices, but through a capacitor connected in parallel with the load, which binds the corresponding diode and most self-locking relay.

The absence of feedback and constant bias circuits simplifies the switching device and increases its reliability.

Pa figs. 1 shows a schematic diagram of the proposed magnetic relay (transitional device) in conjunction with a control circuit; in fig. 2 - magnetization curve of the core of this relay.

As can be seen from FIG. 1, three windings are superimposed on the relay core made of a material with a rectangular hysteresis loop — two excitation windings W and one control winding W. Excitation windings Wi and W are fed through diodes D and D2 from according to the included windings Wl and W2 of the transformer. The load is connected between the common points of the windings W, W relays and windings IF ,, W of the transformer and shunted by capacitor C.

It is assumed that at the initial moment the core has a positive residual magnetic induction (Fig. 2). When applied to the winding W of the core and the R-C chain from the winding W of a negative half-wave transformer (half period a – b) sinusoidal with amplitude, the core is re-magnetized and its magnitude changes during this half-period to-B or --Sr.

In the process of magnetization reversal, the inductance of the core is very high, however, almost all of the applied voltage falls on the winding Wi, and the voltage on the capacitor C and the load resistance is negligible.

A positive half-wave of sinusoidal voltage with an amplitude value goes to the winding Wz of the core and the chain R-C and remagnetizes the core, changing its induction to + B. At the same time, the load voltage is again low.

If during the positive half-wave it is not allowed the core to remagneti and T bc I am, so that its induction value remains equal - B or -b, then with the subsequent negative half-wave to the winding Wi and the -C chain the core magnetization will occur for a small part a-b a half-period a-b (if the change in induction occurs from - ,. to B,.) when there is a large inductive resistance of the winding Wi, or for even less time (if the core starts to reverse the magnetic field from the state -B along the horizontal branch of the curve magnetization, where the change in induction is determined by the degree of hysteresis loop incompetence). Therefore, in this half-period, starting from moment b, or somewhat earlier, most of the applied voltage is released on the load, which causes the charge of the capacitor C to a voltage close to / "l. The time constant of the chain is chosen such that during the positive half-period the voltage on the capacitor C is greater than the voltage applied to the winding Wz and the chain. Therefore, the diode Dz appears to be locked, and the induction of the core remains equal - V, ..

Consequently, in the next negative half-period, capacitor C is recharged and re-closes the diode Mz during the positive half-period.

The change in the induction of the core along the negative horizontal branch of the hysteresis loop is the operating mode of the magnetic relay, in which the core practically does not re-magnetize, which allows, due to the small resistance of the winding Wi, to release considerable power on the load.

In the operating mode, the magnetic relay can be indefinitely long. The transfer of the magnetic relay to idle mode, in which the core is completely or almost completely re-magnetized from -B, (or -B) to + B and vice versa and power is not released at the load, is accomplished by changing the induction of the core from -B to + B. For this purpose, a winding W is used, over which control from the distributor takes place. A positive pulse comes from the output winding of the latter through the diode Dz, locking the diode D, thus preventing the possibility of changing the core induction from -B to + B. However, the same pulse, the passage through the diode D winding W and the resistance RI and 2, remagnetizes the core, changing the induction to + B,.

When a command is issued from the output winding of the memory device, a impulse is received on the resistance, which blocks the passage of the pulse from the distributor along the indicated circuit, as a result of which the core does not oscillate and its induction remains –B, i.e., the relay is turned on.

If the command is not transmitted, then the blocking pulse is not removed from the resistance, the core is re-magnetized and the relay is turned off.

Subject invention

Magnetic relay (switching device) with a core of material having a rectangular magnetization curve and with three windings: one control winding and two excitation windings connected according to and fed through diodes from according to the transformer windings connected, and the load is connected between the common points of the relay windings and a transformer, characterized in that, in order to obtain a switching mode without using feedbacks and a constant biasing, a condenser is connected in parallel with the load And the number of windings of the feed transformer windings is selected so that when the core voltage reversal of the capacitor prevyschalo supply voltage for the locking of the corresponding diode and eliminating the possibility of repeated magnetization reversal of the core before the arrival of the control signal.

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