US1550877A

US1550877A - Electric relay

Info

Publication number: US1550877A
Application number: US83327A
Authority: US
Inventors: Chaffee Emory Leon
Original assignee: Individual
Current assignee: Individual
Priority date: 1916-03-10
Filing date: 1916-03-10
Publication date: 1925-08-25
Anticipated expiration: 1942-08-25

Description

ELECTRIC LAMP 8c DISCHARGE I DEICES, SYSTEMS. f 6? Aug 25 was. 1,550,877

E. L. CHAFFEE ELECTRIC RELAY Original Filed March 10, 1916 L 0 as 3.5 3 Li 39, .5 9 6 t WITNESS 64 Patented Aug. 25, 1925.

UNITED STATES PATENT OFFICE.

EMORY LEO-N CI-IAFFEE, OF BELMONT, MASSACHUSETTS, ASSIGNOR TO JOHN HAYS HAMMOND, 3B,, OF GLOUCESTER, MASSACHUSETTS.

nnno'rnrc RELAY. I

Application filed March 10, 1916, Serial No. 83,327. Renewed September 11, 1923.

To all whom it may concern:

Be it known that I, EMORY LEON CHAFFEE, a citizen of the United States, and a resident of Belmont, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Electrio Relays, of which the following is a specification.

One of the objects of this invention is to provide in an electric relay including a detector improved means for reducing the persistence of the operation of the detector after the impulse which initiated such operation has ceased.

Further objects of this ,invention are to provide in an electric relay including a detector, improved means for increasing the sensitiveness of the detector by permitting the detector to be normally adjusted very close to the point of breaking down; and to provide other improvements as will appear hereinafter.

In the accompanying drawing, Fig. 1 is a diagrammatic illustration of an electric relay constructed in accordance with this invention; and Figs. 2 and 3 are fragmentary diagrammatic views of modified forms of the same.

Referring to the drawings, one embodiment of this invention comprises a gaseous detector of the mercury type including the usual or any suitable air tight glass bulb or container 10, from the interior of which practically all gases have been exhausted. The lower portion of the bulb is extended downwardly to form a well 11 which contains mercury forming a cathode 12. The lower portion of the bulb is also provided with the usual reservoir 13 containing mercury 14.

Within the bulb 10 and spaced slightly above the mercury cathode 12 is a flat horizontal annular metal plate 20 forming an anode which is supported in a fixed position by the inner end of a substantially rigid metal conductor 21, the outer end of which projects tightly through the bulb 10 and is sealed in. position. The portion of this conductor 21 within the bulb 10 is preferably surrounded by a glass tube 22 or other insulator.

In the upper portion of the bulb 10 is a flat horizontal circular metal plate 25 forming an electrode which is supported in a fixed positio 0L i l-16 1QW61 end. of a vertl al rigid metal conductor 26, the upper portion of which projects tightly through the bulb 10 and is sealed in position. The portion of the conductor 26 within the bulb 10 is preferably surrounded by a glass tube 27 or other insulator. J

Extending through the mercury cathode 12 is a vertical conductor 30, the upper end of which is preferably provided with a platinum tip 31 which projects slightly above the mercury and in alinement with the central opening in the anode 20 to render the oathode spot of the arc discharge stationary. The lower end of the conductor 30 projects tightly through the wall of the well 11 and is sealed in position.

The bulb 10 and contained elements are arranged to control an outgoing or controlled circuit including a source of alternating potential 35, one pole or brush 36 of which is connected by a conductor 37 with the lower end of the conductor 30, and the other pole or brush 38 of which is connected by a conductor 39 and through the conductor 26 with the uppermost electrode 25. The conductor 39 extends through and controls a relay 40 or any other suitable device.

A battery has a positive pole connected through a conductor 46, regulating or variable resistance 47, inductance 48 and conductors 49 and 21 with the anode 20. A negative pole of the battery is connected by a conductor 50 and the

conductors

37 and 30 with the mercury cathode 12.

Fixedly secured within the bulb 10 and spaced a suitable distance below the terminal or electrode 25 is a flat circular perforated metallic grid or potential gradient changing means of the usual or any suitable con struction. From this grid leads a conductor 56 to one end of an inductance 57 the other end of which is connected by a conductor 58 to one end of a high resistance 60. The proper magnitude of this high resistance 60 should be experimentally determined for each particular bulb 10. It has been found that in ordinary cases and with such bulbs as are generally used the best value of this high resistance 60 ranges from a few thousand to twenty or thirty thousand ohms, depending upon the bulb used. Instead of connecting the resistance 60 between the conductor 58 and the contact 61, it might be inserted in the conductor 56, as shown in Fig. 2. In ny a he resistance, 60 may be either a non-inductive resistance, as shown in Figs. 1 and 2, or an inductive resistance, as shown in Fig. 3, but preferably a noninductive resistance. The other end of the high resistance 60 is connected to a movable contact 61 which adjustably engages a stationary resistance 62 forming a potentiometer. One end of the latter resistance 62 is connected by a conductor with a negative pole of the battery 45, while the other end of the resistance 62 is connected by a conductor 64 and adjustable contact 65 with a positive pole of the battery 45. A condenser 66 is interposed between the

conductors

56 and 58, and cooperates with the inductance 57 in forming an oscillatory circuit.

The circuit including the inductance 57, high resistance 60, variable resistance 62, and conductor 63, may be designated the in coming or controlling circuit, and the whole combination thus far described constitutes an electric relay arranged to control a secondary relay 40.

The inductance 57 forms the usual secondary coil of a tuning transformer, the primary coil or inductance '70 of which is loosely coupled to the secondary inductance 57. The primary inductance 70 forms part of an antenna or open aerial circuit 71 which is grounded through an adjustable contact 72 and conductor 7 3.

In the operation of a relay constructed as hereinbefore described, a quiet arc is normally maintained between the mercury cathode 12 and the annular anode 20 by the battery 45. The grid is normally maintained at a certain definite potential between that of the anode 20 and that of the mercury cathode 12 by a suitable adjustment of the

potentiometer

61, 62, and the adjust-able contact 65. Under these conditions, the distribution of the potentials in the bulb 10 is such that normally substantially no current flows from the source of alternating potential 85 through the relay 40 and bulb 10, but if the potential of the grid 55 be even slightly increased, as for instance in a well known manner in response to an impulse of radiant energy received by the antenna 71, then the normal apparent resistance of the interior of the bulb 10 will be apparently decreased in a well known manner and a rectified current will flow from the source of alternating potential through the conductor 39 and relay 40 to the electrode 25 from which the greater portion of the current will pass through the interior of the bulb 10 to the mercury cathode 12 andthenceback through the conductor 37 to the source 85. While this is taking place, however, some of the rectified current will be passing from the electrode 25 to the grid 55 and then through the side or

grid circuit

56, 57, 58, 60, 61, 62, 63 and 37 and back through the mercury cathode 12. It is thought that in old forms of detectors as heretofore constructed and connected, this flow into the grid 55 and through the grid circuit has caused an undesirable modification in the distribution of potentials in the bulb 10 which has resulted in a sufficient increase in the potential of the grid 55 to cause the discharge from the electrode 25 to persist even after the excitation which has caused the initial increase in the potential of the grid has ceased. The result of this action of the grid circuit has been to cause the interior of the bulb 10 to remain in a conductive condition and to permit a rectified current to flow through the bulb 10 from the source 35, after the cessation of the impulse which initiated the operation 01 the detector, and consequently the detector has thus been rendered inoperative to respond to a second impulse.

One of the advantages of this improved construction, is that the high resistance which has been inserted in the grid circuit, so much increases the resistance of the grid circuit, that the amount of rectified current which is shunted oil through the grid circuit is greatly reduced and the tendency of the conductivity of the interior of the bulb to persist is consequently greatly reduced, and to such an extent as to practically avoid having the detector continue to operate after the cessation of the impulse which has initiated its operation.

A further advantage of this improved construction is that the use of the high resistance 60 in the grid circuit makes it possible to adjust the normal voltage of the grid much nearer to the break-down-potential, or, to the point of breaking down, thus greatly increasing the sensitiveness of the bulb The addition of the high resistance 60 does not in any way interfere with the effective operation of the detector. Since normally there is practically no flow of current in the grid or

incoming circuit

55, 56, 57, 58, etc., the presence of the high resistance 60 in this circuit does not cause any drop in potential, so that the potential of the grid 55 will be governed by the.

potentiometer

61, 62 as before.

Although this invention has been shown as applied in a mercury vapor detector and only in a single construction and arrangement of connections, it is to be understood that the invention is not limited in its application to any particular form of gaseous or other detectors or to any particular construction or arrangement of connections, but might be applied in various forms of detectors and with various connections without departing from the spirit of the invention or the scope of the appended claims.

Having thus fully described this invention, I claim:

1, An electri rel y c mpris g a control- ELECTRIC LAMP 8c DISCHARGE.

"7 OW a ling circuit including in series potential gradient changing means, a high resistance, and means arranged to respond to external variations of potential, and a circuit controlled by said first mentioned circuit and including a source of potential, said second mentioned circuit being so adjusted that normally substantially no current flows therethrough.

2. An electric relay comprising a control ling circuit including in series potential gradient changing means, a high resistance,

and means arranged to respond to electrical impulses, and a circuit controlled by said first mentioned circuit and including a source of potential, said second mentioned circuit being so adjusted that normally substantially no current flows therethrough.

3. An electric relay comprising a container, a cathode, an anode, potential gradient changing means, and an electrode spaced in said container, means for maintaining an electric are between said cathode and said anode a controlling circuit connecting said potential gradient changing means and said cathode and including in series with said means a high resistance and means arranged to respond to external electrical impulses, and a circuit including said cath ode, said electrode and a source of potential, the construction and arrangement being such that normally substantially no current flows through said second mentioned circuit, and said resistance being so proportioned that substantially no rectified current will be permitted to pass between said potential gradient changing means and said cathode through said controlling circuit.

4. An electric relay comprising a container, a cathode, an anode, potential gradient changing means, and an electrode spaced in said container, means for maintaining an electric are between said cathode and said anode a controlling circuit connecting said potential gradient changing means and said cathode and including in series with said means a high impedance and means arranged to respond to external electrical impulses, and a circuit including said cathode, said electrode and a source of potential, the construction and arrangement being such that normally substantially no current flows through said second mentioned circuit, and said impedance being so proportioned that substantially no rectified current will be permitted to pass between said potential gradient changing means and said cathode through said controlling circuit.

Signed at Cambridge in the county of Middlesex and State of Massachusetts this second day of March A. D. 1916.

EMORY'LEON'GHAFFEE.