SU62197A1 - Bit device - Google Patents

Description

The implementation of control valves with a heated cathode at high current strengths is very difficult for the following circumstances:

a) considerable power released inside the iribor;

b) the impossibility of fully using the emitting surface of its cathode without greatly increasing the size of the iribor.

The first reason causes the high temperature of all parts of the device and causes the appearance of emission currents from both the control element and shielding parts. Emission currents typically increase during the life of the instrument due to the continuous spraying of the cathode active substance and the condensation of its control element and screens. Having reached a certain critical value (often less than a few micrometers), they lead to spontaneous unlocking of the device, i.e., make it uncontrollable

The second reason - poor use of the emitting surfaces of the cathode - leads to a low service life of the device at the cathode.

Both of these shortcomings, which make the powerful controlled device short-lived, are eliminated in the proposed bit device, which is the subject of the present invention.

FIG. 1 shows the basic structure of a lamia; or FIG. 2 - the design of a controlled device with a ikaleyny cathode, g, which used the new principle of discharge control; in fig. 3 - device switching circuit; in fig. 4 - oscillograms of currents And voltages; in fig. 5 - mercury flask, controlled by the proposed method; in fig. 6 - a mercury metal rectifier, in which the control is made not by the grid, but according to the invention - finely: by a thread passing axially through the shield of the anode.

The device is based on the following physical phenomenon. If, as the anode in a gas-filled device with a hot cathode, we take a long thin filament 2, moving away from the cathode 1, as shown in FIG. 1, when a positive (with respect to the cathode U) potential is applied to the filament 2, the discharge will not burn on the part of the filament closest to the cathode, but will propagate along the entire filament, whatever

No. 62197-2 -

its length. The reason for this lies in a significant positive anodic drop occurring in the anodes with a small electron-collecting surface. If a second (working) anode 3 is placed near the end of the filament far from the cathode, then the ignition potential between it and the cathode / will decrease greatly if there is a weak additional discharge along the filament.

The lamp shown in FIG. 1, was made and showed the following results: in the absence of a discharge per filament 2, the ignition potential (for this lamp) between the cathode / and anode 3 was 350. e. However, it suffices to create a filament at the current in the filament - cathode circuit, equal to only 0.5 ma, as the potential for ignition drops to 20 in.

By applying an alternating voltage with an amplitude of less than 350 V to the anode 5, it is possible to control the magnitude of the rectified current, which was checked by the author.

In a powerful control device with a heated oxide cathode in FIG. 2, the cathode 1 is shielded from the anode 3 with the help of parts 4 and 5, that at a positive voltage at the anode, with a larger amplitude of the operating voltage, the discharge to the anode does not ignite. It will be lit only if the additional control electrode - thread 2 is given a positive potential sufficient to form a discharge (the control thread is isolated from the cathode and the anode by insulators 6).

Since the plasma will surround the entire filament 2, i.e., and its upper part, located in the appreciable anode field, the ignition potential on the working anode 3 will drop dramatically and ignition will occur.

Turning on: In the cathode 1 circuit - thread 2 peak transformer, you can control the average value of the rectified voltage. In order to explain what is said in FIG. 3 shows the circuit for switching on the device and FIG. 4 - oscillograms of currents and voltages in it.

Here, 1, 2, 3 is the proposed device, 7 is a peak transformer, an 8-phase shifter, 9 is a load, 10 is an anode transformer, 11 is a limiting resistance, ea is the supply voltage, ep is the voltage of the peak transformer, unit is rectified voltage, // - rectified current.

The discharge control method used according to the invention is also suitable for devices with a liquid cathode. The mercury flask, controlled by the proposed method, is shown in FIG. 5 (/ - liquid cathode, 2 - control filament and 3 - anode). In a mercury metal rectifier according to FIG. 6 a thin control line 2 has been passed through the shielding of the anode 3; here 12 is a low permeability deionization lattice and 13 is a cuff. The principle of operation of discharge devices with liquid cathode sen from the above is higher.

Subject invention

Claims (2)

1. Discharge device equipped with a control electrode placed between the main electrodes, characterized in that a thin filament placed along the axis of the discharge space and isolated from the main electrodes is used as the control electrode. 2. The form of the apparatus according to claim 1, characterized in that the thin filament is placed inside the screens limiting the discharge. Rig / .four 9ig5 d "a. iS 12 FIG B