US1840055A

US1840055A - Glow relay tube

Info

Publication number: US1840055A
Application number: US252437A
Authority: US
Inventors: Rentschler Harvey Clayton
Original assignee: Westinghouse Lamp Co
Current assignee: Westinghouse Lamp Co
Priority date: 1928-02-07
Filing date: 1928-02-07
Publication date: 1932-01-05
Anticipated expiration: 1949-01-05
Also published as: FR668879A; GB305574A

Description

Jan. 5, 1932. H. c. RENTSCHLER Q GLOW RELAY TUBE Filed Feb. 7, 1928 FlEl I2 wmmm HIIIIIIIIII INVENTOR H.C.PENTscHLcR ATTORNEY Patented Jan. 5, 1932 umrso srArEs Mm orrics HARVEY CLAYTON RENTSCHLER, OF EAST ORANGE, NEW JERSEY, ASSIGNOR TO WES T- INGHOUSE LAMP COMPANY, A CORPORATION OF PENNSYLVANIA GLOW RELAY TUBE Application filed February 7, 1928. Serial Jim-252,437.

This invention relates to an electrical discharge device of the gaseous conduction type and more particularly to such a device in which the discharge takes place between cold electrodes in a gaseous atmosphere at a re duced pressure.

One of the objects of this invention is to provide a gaseous conduction discharge device having extremely sensitive means for controlling the discharge therethrough.

Another object is to provide a gaseous conduction discharge device capable of delivering relatively large currents and having means operated by extremely feeble current changes for controlling the discharge.

A further object is to provide a gaseous conduction device which normally interposes a high resistance to the passage of current therethrough at a predetermined voltage and which has means operative by relatively feeble currents in a supplementary circuit for reducing such resistance so as to permit a relatively large flow of current at said predetermined voltage.

A still further object is to provide aigaseous conduction relay which will operate at relatively low voltages and which is extremely sensitive to current changes in a supplementary circuit.

Other objects and advantages will hereinafter appear.

It is well known that the voltage required to initiate an electrical discharge in a glow discharge device is higher than that required to maintain the discharge once it has started. Thus, for instance, in voltage regulators, alternating current rectifiers, lamps, etc., employing spaced apart electrodes in a gaseous atmosphere and operating in the absence of thermionic emission, by a proper choice of electrode materials, electrode space, gas pressure, etc., the discharge may be made to start at a potential of around 120 volts, while the discharge once started will continue at potentials as low as 85 to 90 volts, depending somewhat upon the current passing through the tube. This difference in starting and operating potential is due largely to the high resistance imposed by the cathode dark space. Upon initiation of a discharge in the device,

this resistance layer is broken down and permits the discharge to continue on a voltage lower than the starting potential or another independent discharge to be started at a materially lower voltage.

It has also been found that there is a definite spacing of the electrodes for a particular gas and a particular pressure thereof at which the voltage required to initiate the discharge is a minimum. Moreover, whereas, devices of this nature may readily carry currents up to several hundred milli-amperes, the amount of current required to start the discharge is exceedingly small, that is, in the nature of only a few micro-amperes.

I make use of the above phenomena for the production of a sensitive glow relay tube and than that required to start the discharge from the main anode.

In the specific embodiment illustrated hereinafter, the control anode is positioned at the critical distance from the cathode at which the minimum voltage is required with the particular gas at the pressure employed to start the discharge to the cathode. The main anode is arranged at a sufficient distance from the cathode to prevent the start ing of a discharge therefrom except at materially higher voltages. As a consequence of this construction, if a predetermined voltage is impressed between the main anode and cathode, below that necessary to initiate a discharge therebetween but sufficiently high to maintain such discharge once it has started and if a second source of potential is a plied between the control anode and catho e of sufiicient potential to initiate a discharge fully understood, reference will be had to the accompanying drawings'in which:

Fig. 1 is an elevation, partly in section, of a tube employing my invention associated with electrical apparatus for controlling the operation thereof;

Fig. 2 is an elevation, partly in section, of a modified form of electrode arrangement;

Fig. 3 is a diagrammatic showin of the tube of Fig. 1 associated with a modified form of control apparatus;

Fig. 4 is a view similar to Fig. 3 showing another modification of the control apparatus; and,

Fig. 5 is another view similar to Fig. 3

showing a still further modification of the control apparatus.

The device shown in Fig. 1 comprises an envelope 1 containing a cathode 2, main anode 3 and control anode 4. The

electrodes

2, 3 and 4 are suitably supported by a ress 5 and are joined to leading-in wires 6, and 8 respectively. A metallic projection 9 extends outwardly from the cathode 2 into proximity to the control anode 4. The space between the control anode and the end of the projection 9 should be such as to enable the minimum potential to be obtained for starting the discharge between the

electrodes

2 and 4. This distance is dependent upon the particular gas employed and the pressure thereof. For instance, with a filling of argon gas at a pressure-from 5 to 8 millimeters of mercury, a spacing of approximately 1 mm. has been found to give the requisite low potential starting condition. If other pressures are used or other gases employed, it-may be necessary to vary the spacing of the control anode from the cathode.

The main anode 3 is spaced a much greater distance from the cathode than the control electrode. In the practical embodiment of the invention employing the gas pressure specified above, excellent operating characteristics' were obtained with a cylindrical cathode 2 of 1 inch in diameter havin the main anode 3 located at the axis thereo In order to reduce the starting and operating potentials of the device, an electro-positive metal, such as one of the alkali metals or alkaline earth metals or a less volatile metal such as misch metal may be vaporized on to the cathode to form a surface layer thereon.

and 3 of the device. The resistance to current flow between the anode 3 and the cathode 2 is such that no discharge will normally pass therebetween at the voltage available from the line 10.

The control anode 4 is also connected to one side of the line 10 opposite from that of the cathode by a conductor 14, through a high resistance 15 and a switch 16. The resistance 15 limits the current which may pass between the

electrodes

4 and 2 to a small value. The voltage of the line 10 is such that when the switch 16 is closed, the small current passing the resistance 15 at low voltage will start a discharge from the control ano to the cathode, thus ionizing the gaseous filling and breaking down the cathode resistance.

Immediately this occurs, the resistance between the main anode 3 and the cathode becomes sufliciently decreased to cause a discharge therebetween, thus permitting a relatively heavy current to flow through the line 11 and the winding of the relay 13. This operates the switch 17 and energizes the circuit 18 for any desired purpose.

In the modification shown in Fig. 1 the switch 16 may take the form of a bi-metallic thermostatic element which, upon attaining a predetermined temperature closes or opens, thereby starting or stopping the discharge from the main electrodes and rendering available relatively heavy currents for operating the relay 13 without necessitating the passage of such relatively heavy current directly through the switch 16.

Fig. 2 illustrates a modified form of relay in which the control anode 4 is rovided with a head' 19 of a material which is more active than that of the electrode 3. For instance,

electrode 3 may be composed of a metal such as nickel and the anode head 19 of a material such as thorium, titanium or uranium which has the property of still further decreasing the potential required to initiate a discharge.

In this manner the differential of potentials required to start the main and control or trigger discharge is increased. The active material constituting the control anode head 19 also exercises a clean-up action or gas purifying effect to maintain the gaseous filling in a more pure condition. If desired, the anode head may be coated with barium oxide which is reduced by the thorium or other active material, to liberate barium metal. The barium metal vaporizes onto the surface of the cathode 2 and serves to maintain the cathode drop -the main discharge is controlled by means of temperature variations. In Fig. 3 an arrangement is shown whereby this control is obtained by variations in intensity of a source of light. In this latter figure, the control electrode 4 is joined to the line 10 by a conductor 20 through a photo-electric cell or other like sensitive device 21. The main anode 3 is joined to the line 10 through therelay 13, the same as in Figure 1 and the oathode is joined to the opposite side of the line. Light falling upon the photo-electric cell 21 permits a small discharge to ass therethrough from the line 10, there y starting the control or trigger discharge and thus enabling the main discharge to start. A battery 22 or other source of potential may be connected in circuit with the photo-electric cell 21 to boost the voltage of the line 10 and thereby facilitate the starting of the discharge.

In Fig. 4, a condenser 23 is shown as a current limiting means between the line 10 which may be of the thermostatic type shown in Fig. 1 or any other suitable type, either manually or automatically controlled, is provided for controlling the trigger discharge and thereby the main discharge or the disand the control electrode 4. A switch 24,

I charge in the control circuit may be initiated by merely changing the capacity of the condenser 23, as by gether.

In Fig. 5 there is shown an arrangement in which the control electrode 4 is joined to a condenser 25 which may consist of a sheet of glass 26 which is coated on one side with a metallic substance 27 such as tin foil. The other side of the condenser may be formed by placing the hand on the opposite side of the glass 26 from the coating 27, thus completing the circuit to the rounded line conductor 28. The capacity eect produced at the control anode by bringing the hand or other portion of the body close to the plate 26 causes sufiicient current to flow to start the discharge. This current may be augmented, however, by a high resistance 28 interposed between the main anode 3 and the control anode 4. The resistance 28 should be high enough to prevent suflicient current passing to the control anode to operate the control discharge in the absence of the current set up by the capacity effect produced by bringing a grounded object near the insulating plate 26. Upon initiation of the trigger discharge, the main discharge starts,-thus energizing a sensitive polarized relay 29 to close the switch 30 and thus energize a power relay 31 through the secondary winding 32 of a transformer 33 energized from the line 10. The power relay 31 operates a switch arm 34 for closmoving the plates closer to- "of my invention,

may be employed in other connections for ing the circuit to any suitable electrical apparatus 35.

While I have shown several applications it is to be understood that it various purposes and that the details of construction may also be varied within wide limits without departing from the invention.

What is claimed is:

1. In combination a gaseous conduction de-' vice comprising an enclosing glass envelope, an inert gas filling, a cathode of relatively large area superficially coated with an electro-positive metal, a main anode, a second anode spaced closer to the cathode than said main anode, electrical circuits associated with said cathode and anodes, said circuits including means to impress on said-closer spaced anode electrode an electrical potential sulficient to initiate a glow discharge between said electrode and said cathode and means to impress on said main anode an electrical potential suflicient to maintain the initiated discharge.

2. In combination a gaseous conduction device comprising an enclosing glass envelope, an inert gas filling, a cathode of relatively large area superficially coated with an electro-positive metal, a main anode, a second anode spaced closer to the cathode than said main anode, electrical circuits associated with said cathode and anodes, said circuits including means to impress on said closer spaced anode electrode an electrical potential sufficient to initiate a glow discharge between said electrode and said cathode, means to impress on said main anode an electrical potential suflicient to maintain the initiated discharge and means energized by the current flow in the main anode circuit as a result of said maintained glow discharge to actuate external mechanism.

3. In combination a gaseous conduction device comprising an enclosing glass envelope, a filling of argon at reduced pressures, a cathode of relatively large area superficially coated with an electro-positive metal, a main anode, a second anode spaced closer to the cathode than said main anode, electrical circuits associated with said cathode and anodes, said circuit including means responsive to predetermined conditions to impress on said closer spaced anode electrode an electrical potential sufficient to initiate a glow discharge between said electrode and said cath ode, means to impress on said main anode an electrical potential sufficient to maintain the initiated discharge and means energized by the current flow in the main anode circuit as a result of said maintained glow discharge to actuate external mechanism.

4. In combination a gaseous conduction device comprising an enclosing envelope, an inert gas filling, a cathode, a main anode, a second anode spaced closer to said cathode than said main anode, at least one of said second anode an electrical potential sufi'icientto initiate a glow discharge between said anode and said cathode, and means to impress on said main anode an electrical potential suflicient to maintain the initiated glow discharge.

5. In combination a gaseous conduction device comprising an enclosing envelope, an inert gas filling, a cathode, a lurality of electrodes, one of which electro es is spaced closer to said cathode than the other electrodes, at least one of said electrodes being "comprised at least superficially of thorium,

electrical circuits associated with said electrodes said electrical circuits including means associated with said closer spaced electrode to initiate a glow discharge between said electrode and the cathode, means associated with at least one of said other electrodes to maintain the initiated glow discharge and means energized by the current flow of said main tained glow discharge for actuating external mechanism.

6. In combination a gaseous conduction device comprising an enclosing envelope, an inert gas filling, a cathode, a plurality of electrodes, one of which electrodes is spaced closer to said cathode than the'other electrodes,'at least one of said electrodes being comprised at least superficially of thorium, means associated with said cathode to stabilize the cathode drop in potential, electrical circuits associated with said electrodes said electrical circuits including means associated with said closer spaced electrode to initiate a glow discharge between said electrode and the cathode, and means associated with at least one of said other electrodes to maintain the initiated glow discharge.

7 In combination a gaseous conduction device comprising an enclosing envelope, an

inert gas filling, a cathode, a plurality of electrodes, one of which electrodes is spaced closer to said cathode than the other electrodes, at least one of said electrodes being comprised at least superficially of thorium, means associated with said cathode to stabilize the cathode drop in potential, electrical circuits associated with said electrodes said electrical circuits including means associating with said closer spaced electrode to initiate a glow discharge between said electrode and the cathode, means associated with at least one of said other electrodes to maintain the initiated glow discharge and means energized by the current flow of said maintained glow discharge for actuating external mechanism.

8. In combination'a gaseous conduction device comprising an enclosing envelope, an

second anode spaced closer to said cathode than said main anode, at least one of said inert gas filling, a cathode, a main anode, a

second anode spaced closer to said cathode than said main anode, at least one of said electrodes being comprised at least superfi cially of thorium, and electrical circuits associated with said cathode and anodes, said circuits including means to impress on said second anode an electricalpotential sufiicient to initiate a glow discharge between said anode and said cathode, means to impress on said main anode an electrical potential suflicient to maintain the initiated glow disinert gas filling, a cathode, a. main anode, a

charge, and means'energized by the current flow of said maintained glow discharge for actuating external mechanism.

10. In combination a gaseous conduction device comprising an enclosing envelope, an inert gas filling, a cathode, a main anode, a second anode spaced closer to said cathode than said main anode, at least one of said electrodes being comprised at least superfi-- cially of thorium, means associated with said cathode for stabilizing the cathode drop in potential, and electrical circuits associated with said cathode'and anodes, said circuits including means to impress on said'second anode an electrical potential suflicient to initiate a glow discharge between said anode and said cathode, and means to impress on said main anode an electrical potential sufficient to maintain the initiated glow dis charge.

I 11. In combination a gaseous conduction device comprising an enclosing envelope, an inert gas filling, a cathode, a main anode, a second anode spaced closer to said cathode than said main anode, at least one of said electrodes being comprised at least superficially of thorium, means associated with said cathode for stabilizing the cathode drop in potential, and electrical circuits associated with said cathode and anodes, said circuits including means to impress on said second anode an electrical potential sufficient to initiate a glow discharge between said anode and said cathode, means to impress on said main anode an electrical potential suflicient to maintain the initiated glow discharge and means'energized by the current flow of said maintained glow discharge for actuating external mechanism.

12. In combination a gaseous conduction device comprising an enclosing envelope, an inert gas filling, a cathode, a main anode, a second anode spaced closer to said cathode than said main anode, at least one of said electrodes being comprised at least superficially of thorium, and electrical circuits associated with said cathode and anodes, said circuits including means responsive to predetermined conditions to impress on said second anode an electrical potential sufiicient to initiate a glow discharge between said anode and said cathode, and means to impress on said main anode an electrical potential suflicient to maintain the initiated glow discharge.

13. In combination a gaseous conduction device comprising an enclosing envelope, an inert gas filling, a cathode, a main anode, a second anode spaced closer to said cathode than said main anode, at least one of said electrodes being comprised at least superficially of thorium, means associated with said cathode for stabilizing the cathode drop in potential, electrical circuits associated with said cathode and anodes, said circuits including means responsive to predetermined conditions to impress on said second anode an electrical potential sufficient to maintain the initiated glow discharge and means energized by the current flow of said maintained glow discharge for actuating external mechanism.

14. In combination a gaseous conduction device comprising an enclosing glass envelope, a filling of argon at pressures approximating 8 m. m.. a cathode of relatively large area superficially coated withmisch metal, a main anode, a second anode spaced closer to the cathode than said main anode, at least one of said electrodes being comprised at least superficially of thorium, electrical circuits associated with said cathode and anode, said circuit including means responsive to predetermined conditions to impress on said closer spaced anode electrode an electrical potential sufficient to initiate a glow discharge between said electrode and said cathode, means to impress on said main anode an electrical potential sufiicient to maintain the initiated discharge and means energized by the current flow in the main anode circuit as a result of said maintained glow discharge to actuate external mechanism.

In testimony whereof, I have hereunto subscribed my name this 3rd day of February, 1928.

HARVEY CLAYTON RENTSCHLER.