SU40464A1 - Relays for AC circuits using an ionic device - Google Patents

Description

A whole series of relays are already known that use ion-discharge devices, such as thyratrons, the anode circuit of which is powered by an alternating current circuit. The latter is dictated by the fact that in the case of supplying the anode circuit with a direct current, the ion relay loses the ability to turn on and off repeatedly. In addition, an ionic relay powered entirely from an AC mains is very advantageous for economic reasons, since such a relay requires neither batteries, nor rectifiers, nor any other power sources.

However, almost all existing types of ionic relays, when powered by alternating current, reveal a number of shortcomings. The main one of these drawbacks is that the current in the anode circuit of the ion relay is not constant, but has the form of individual pulses (this is true even in the case when the load of the relay has significant inductance).

In many cases, the presence of gaps in the current delivered by the ion relay can be a serious obstacle to the use of the latter.

Quite often, ionic devices are used as auxiliary relays, i.e. the current they give feeds some more powerful, for example, electromagnetic relay, which already, in turn,

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performs the necessary switching in the circuit.

In this case, the presence of a ripple in the current of the ion relay entails the fuzzy operation of the electromagnetic relay (the measles of the latter is not attracted with constant force, but vibrates, the sensitivity of the relay drops, etc.). Equally, the presence of these current pulsations is adversely affected at work if the ion relay directly serves to power receivers such as the excitation windings of a dynamo or a switch electromagnet (for example, an oil switch).

Various smoothing devices, filters, etc., are usually used to eliminate current ripple, but essentially none of them provides real results. The present invention consists in the specific form of the implementation of the above-mentioned relay and is intended to achieve a smoothing of the current pulsations in it without the use of any special devices.

In FIG. 1 shows the circuit for switching on the proposed relay; FIG. 2 is an oscillogram of the relay currents in FIG. one; FIG. 3 and 4 are various forms of the design of the ion device ;, FIG. 5 is a circuit for switching on a relay if it is used as a photo relay.

The relay is equipped with a hot cathode 3, control grid 2, one

a controlled anode / and one auxiliary anode 4. According to the image, an alternating current source b is connected between the main 7 and auxiliary 4 anode, and a load 5 is connected between the cathode 3 and the auxiliary anode 4. The load can be, for example, the coil of the electromagnetic relay, coil driving a dynamo, etc.

The control (grid) voltage is supplied to the terminals 13.

From a review of the waveform in FIG. 2, where 6 is the voltage curve in the AC network, 7 is the current through the main anode, 7, 8 is the current through the aHQR auxiliary, 4, 9 is the current curve through the load, it is seen that the current passes through the load as during a positive, and during the negative half-cycle, it is powered by its AC relay.

In this case, during the positive half-period, the current passes through the main anode 7 and electromagnetic energy is stored in the load inductance.

During the negative half-cycle, the load current is closed through the auxiliary anode 4. In this part of the period, the load current flows due to the energy stored in the inductance.

Experience shows that, when using LOJ R, the current through the load will have no discontinuities (L-inductance of the load, R-its resistance, co-frequency of the supply current of the relay).

In most cases, it is easy to obtain an inductive load resistance Z.jt, 5-1.0 times higher than its active resistance R. In this case, the ripple of the load current will be completely insignificant.

FIG. Figures 3 and 4 show possible embodiments of the proposed ion relay.

In the design of an ion relay, the following very important considerations have to be taken into account.

The control electrode (grid) can only control the moment when current passes through the main anode, if there are no positive ions in the space around the grid. Otherwise the mesh is covered.

as if by a case of positive ions and loses completely its controlling properties.

In the described ionic relay, the current through the main anode does not flow during the negative part of the half-period, and the only source of positive ions in this part of the period is the arc burning between the cathode and the auxiliary anode. Therefore, to ensure grid control, it is enough to somehow localize the arc burning between cathode 3 and auxiliary anode 4 so that ions cannot diffuse from it to the grid.

In the proposed embodiments of the ion relay, this localization of the auxiliary arc is achieved by using screens 9 and W. The screen can be made of any conductive substance used in vacuum technology, for example, it can be made of nickel, molybdenum, graphite, etc.

It is advisable to electrically connect the screen with the cathode. At the same time, it can be attached either to the midpoint of the cathode or to one of the ends of the latter. Sometimes it may seem more rational to draw a separate output from the screen and attach an offset of a few volts between the screen and the cathode.

The control grid and the main anode are placed outside the screen. In the drawing, they are indicated by the numbers 2 and 7, respectively. That part of the screen that is opposite the control grid and the main anode must have an opening so that during the positive half-periods of the voltage supply relay, the arc between the cathode and the main anode can burn. In the drawing, this part of the screen is designated by the number W. It can be performed, for example, in the form of a metal grid, a metal sheet with holes, etc.

FIG. 5 shows the inclusion of the proposed relay as a photo relay. Here, as in the scheme of FIG. 1, / - main anode, 2 - control grid, 5-cathode, 5-electromagnetic relay, powered by the current of the ion relay, 6-AC network, 7-photocell. Numbers 19, 77 and 72 denote the photocell, the resistance and the battery bias, respectively.

While the photocell 19 is shaded, the voltage on the grid of the ion relay is below the ignition potential and does not let the current relay through. When a beam of light falls on the photocell, a photocurrent will pass through the resistance 11, the voltage on the grid will become higher than the ignition potential and the ion relay will start to pass the current. When the photocell is first darkened, the ion relay is turned off.

The subject matter of the invention.

Claims (2)

1. Relay for alternating current circuits using an ionic instrument equipped with a hot cathode, control grid, one controlled and one one auxiliary anode, characterized in that the alternating current source is connected between the main 7 and auxiliary 4 anodes, and the load 5 is connected between the cathode 3 and the auxiliary anode 4 (Fig. 1). 2. In the relay of claim 1, the use of an ion device in which the cathode 5 and the auxiliary anode 4 are placed inside the screen 9 of conductive material electrically connected to the cathode, the control grid 2 and the main anode 7 are placed outside the screen, and The screen distant from the auxiliary anode is provided with openings for transmission of the discharge (Figs. 3 and 4).