US2130845A - Electrode arrangement - Google Patents

Description

Sept. 20; 1938. J. VON ISSENDORFF 2,130,845

/ ELECTRODE ARRANGEMENT 'F'iled Dec. 9, 1957 2. INVENTOR Jwyefi V077 fssenaar/f WITNESSES: I $22M /M J1 4JW Patented Sept. 20, 1938 UNITED STATES PATENT OFFICE many, assignor to Siemens-Schuckertwerke Aktiengesellschaft, Berlin-Siemensstadt, Germany, a corporation of Germany Application December 9, 1937, Serial No. 178,935

' In Germany December 19, 1936 6 Claims.

My invention relates to a vapor electric device and particularly for a control system for positively initiating the arc to individual anodes of a multi-anode rectifier.

In the operation of vapor electric devices, particularly high voltage devices, it is desirable to place the anodes in individual anode arms or arc guides, and to control each individual arc path by means of a suitable control electrode such as a controlgrid. It has heretofore been found that in the operation of such devices there is an appreciable lag between the opening of the grid and the initiation of the current carrying arc from the associated anode.

I have discovered that this can be materially improved by inserting an auxiliary anode in the arc guide intermediate betweenthe main anode and the associated control electrode, preferably the auxiliary anode is materially closer to the control electrode than to the associated anode.

Also, in certain instances it is desirable to place a plurality of spaced-apart auxiliary anodes in order to positively control the entire arc path,

particularly if, asin high voltage devices, the

arc path is excessively long. In order to reduce the current consumption of the auxiliary electrodes, they are preferably supplied with potential from an independent auxilary source in phase with the potential applied to the main anodes I and preferably of a lower potential.

It is accordingly an object of my invention to provide a vapor electric device having auxiliary anodes for controlling the initiation of the main arcs in the device.

It is a further object of my invention to provide a control system requiring a nominal amount of power for ionizing the arc paths.

It is a further object of my invention to provide a control system for positively ensuring the L initiation of a main current carrying arc.

Further objects and advantages of my invention will be apparent from the following detailed description taken in' conjunction with the accompanying drawing, in which:

Figure 1 is a schematic representation of a vapor electric device according to my invention, and

Fig. 2 is a similar illustration of a modified form according to my invention.

In the illustrated embodiment according to my invention, a vapor electric device I interconnects an alternating current circuit 2 with a direct current cicuit 3. For simplicity of illustration, I have shown the vapor electric device I as having two anodes 4 and 5 associated with a single ell) phase alternating current circuit 2. However, it is apparent that the invention may likewise be utilized for polyphase circuits. The anodes 4 and 5 are placed at the upper extremities of relatively long anode arms 6 and l or arc guides to provide individual arc paths for each of the anodes 4 and 5. The converter proper being supplied with a suitable vaporizable cathode 8 and having a condensing chamber 9 for condensing and returning the cathode material. Also the converter is preferably provided with suitable means [0 for constantly exciting the cathode 8 during normal operation of the converter I.

Associated with the main anodes 4 and 5 are suitable control electrodes H and I2, preferably placed in the anode arms 6 and 1 adjacent the open end thereof, that is, the end adjacent to the cathode space. Inserted in the anode arms 6 and 1 between the main anodes 4 and 5 and the control electrodes H and I2 are suitable auxiliary or control anodes l3 and I4. These control anodes are supplied with potential from a suitable auxiliary source herein illustrated as an independent winding M in the main transformer l6.

In order to conserve power, this auxiliary source I5 is completely galvanically insulated from the main power source. Preferably the auxiliary source of potential has a lower potential than that applied to the main anodes 4 and 5.

In order to limit the current flowing from the auxiliary source l5 to the control anodes l3 and I4, suitable resistors ll and i8 are inserted in series between the auxiliary potential l5 and the control anodes l3 and M.

However, it is sometimes desirable to have a relatively high initial current flowing through the auxiliary anodes l3 and 14. This may be accomplished by means of capacitor 19 connected between the auxiliary anodes l3 and I 4 and the cathode 8, preferably over portions of the resistors I! and [8. During the inverse half cycle the capacitor IE] will be charged to the potential of the auxiliary source l5 and at the beginning of current flow from the respective control anode the associated condenser will discharge therethrough and thus materially strengthen the initial discharge.

This may also be accomplished as shown in Fig. 2 by supplying capacitors 2E! connected across the current limiting resistances, so that when the control grids H and I2 are properly energized to permit current flow in the arc path, the initial impedance of the condensers 2!] will be relatively low, so that the initial current is accordingly high until the condensers 20 are fully charged, at which time the current will be suitably reduced by the series resistance. Obviously the condenser will be discharged through the resistance during the inverse half cycle.

While any suitable means may be utilized to supply control potential to the control grids, I prefer to have a periodic potential having a steep Wave front such as may be secured by supplying control potential from a control transformer 3i having a saturable core.

In the operation of this modification, the control electrode II or I2 is released by the application of a suitable preferably steep wave front potential, so that the auxiliary or control anode H3 or M carries current which rapidly ionizes the arc space and ensures the ignition of the associated main anode 4 or 5. Since the auxiliary potential I5 is a relatively low potential and since the current is further limited by means of suitable resistors I! and I8, the initiation of the arc to the main anode 4 or 5 will be accomplished with a minimum expenditure of control power.

In the modification according to Fig. 2, a plurality of auxiliary or control anodes 2i and 22 have been inserted between the control grid and a main anode. Preferably the control anode 22 placed the nearest to the main anode is provided with a higher potential than the control anode 2| adjacent the control grid H or l2.

While for purposes of illustration, I have shown and described specific embodiments of my invention, it will be apparent to those skilled in the art that many changes and modifications may be made therein without departing from the true spirit of my invention and the scope of the appended claims.

,I claim as my invention:

1. An electric translating system for transferring electric energy between an alternating current circuit and a direct current circuit comprising a constantly excited vapor electric device, a plurality of main anodes in said device, transformer means for impressing potential on said main anodes, are guides about said main anodes, control electrodes in said are guides, means for impressing control potentials on said control electrodes, auxiliary anodes interposed between said main anodes and said control electrodes and a source of auxiliary potential in phase with but independent of the potential applied to the main anodes, said auxiliary potential being applied to the auxiliary anodes.-

2. An electric translating system for transferring electric energy between an alternating current circuit and a direct current circuit comprising a constantly excited vapor electric device, a plurality of main anodes in said device, transformer means for impressing potential on said main anodes, are guides about said main anodes, control electrodes in said arc guides, an impulsing device for impressing control potentials on said control electrodes, auxiliary anodes interposed between said main anodes and said control electrodes, a source of alternating potential connected to said auxiliary anodes, said source of potential being in phase with and galvanically separated from the potential applied to the main anodes.

3. An electric current conversion system comprising an alternating current circuit, a direct current circuit, a vapor electric device for transferring energy between said circuits, a cathode and a plurality of cooperating main anodes in said device, eachof said anodes being enclosed in an individual anode arm, a control electrode in 1 each of said anode arms, means for applying control potentialto said control electrodes, auxiliary anodes in said arms between said control electrodes and said main anode and an auxiliary source of energy connected to said auxiliary anodes, said auxiliary source of energy being in phase with the potential applied to the main anodes.

4. A converter system for transferring electric energy between alternating and direct current circuits comprising a vapor electric converter, a plurality of anodes in said converter, individual arc paths for each of said anodes, a control electrode associated with each of said are paths, means for impressing alternating potentials on said anodes, a peaking transformer for impressing control potential on said control electrodes, a plurality of auxiliary anodes situated between each of said control electrodes and the associated anode, and an auxiliary source of potential applied to said auxiliary anodes, said auxiliary source of potential being in phase with but galvanically separate from the potential applied to the anodes.

5. A converter system for transferring electric energy between alternating and direct current circuits comprising a vapor electric converter, a plurality of anodes in said converter, individual arc paths for each of said anodes, a control electrode associated with each of said are pathsmeans for impressing alternating potentials on said anodes, a peaking transformer for impressing control potential on said control electrodes, a-plurality of auxiliary anodes situated between each of said control electrodes and the associated anode, and an auxiliary source of potential applied to said auxiliary anodes, said auxiliary source of potential being in phase with but galvanically separate from the potential applied to the anodes, and a capacitor associated with said auxiliary anodes for increasing the initial current flow therefrom.

6. An electric conversion system comprising an arc discharge device, a plurality of anodes in said device, an individual arc path for each of said anodes, means for impressing alternating potential on said anodes, a control electrode associated with each of said arc paths, means for impressing control impulses on said control electrodes, an auxiliary electrode in each arc path between the anode and the control electrode, an auxiliary source of alternating current independent of and in phase with the potential impressed on said anodes and means for impressing the potential of said auxiliary source on said auxiliary electrodes.

JURGEN V. ISSENDORFF.

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