US2679020A

US2679020A - Electrical circuits for arcs with pool-type electrodes

Info

Publication number: US2679020A
Application number: US139941A
Authority: US
Inventors: Lany Beatrice Pearson De; Paul L Copeland
Original assignee: Individual
Current assignee: Individual
Priority date: 1950-01-21
Filing date: 1950-01-21
Publication date: 1954-05-18
Anticipated expiration: 1971-05-18

Description

ELECTRICAL CIRCUITS FOR ARCS WITH POOL-TYPE ELECTRODES Filed Jan. 21, 1950 kwwivfi WM mfifiw E w e e wz m n r a a a X 8 \N 7% (4 J w w M l n 5 I a 2 m 3 kZMwESQ m R Q n m N 3 N w cated by the letters A. C3.

the surfaces.

Patented May 18, 1954 UNITED ELEC'IERICAL CIRCUITS FOR ARCS WITH POOL-TYPE ELECTRODES Beatrice Pearson De Lany, Miami Beach, Fla.., and Paul L. Copeland, Chicago, 111.

Application January 21, 1950, Serial No. 139,941

21 Claims. 1

This invention relates to electrical circuits for pool-type electrodes and has for one object to provide a circuit associated with a pool-type electrode to assure quick starting and rapid initiation of an electric arc.

Another object is to provide a circuit suitable for use in connection with lighting devices which includes pool-type electrodes, and to provide thereby means for suitable operation with alternating current at relatively low voltages.

Other objects will appear from time to time in the specification and claims.

The invention is illustrated more or less diagrammatically in the accompanying drawing, wherein:

Figure 1 is a section through one type of a tube or source of illumination; and

Figure 2 is a section through a modified form shown on a reduced scale;

i is a tube or envelope of any desirable material. It may conveniently be made of glass or other transparent or translucent material. is provided with two portions 2--2 which serve as pool retaining means for pools of material 3, such as mercury or other metal, which will remain fluid at normal operating temperature. i-d are conductors which project into the pool portions 2 and are in electrical contact with the pools 3. These members are connected by wires 5 and 6 to a source of alternating current indi- In the wire 5, or elsewhere in this portion of the circuit, is positioned a current limiting ballast I.

In each of the portions 2, and in contact with their respective pools 3, are funnel-like members 8. These members are preferably formed of semi-conducting material or insulating members or funnels, and are provided with surfaces of semi-conducting material or metal film indicated at 9.

In each of the semi-conductive structures or conductive coatings 9 is a wire or conductor H) which, as shown, may have extensive contact with Each of the members It passes outwardly through the tube or envelope l, and the members it are joined together by a wire or other conductor H which, as shown, is outside of the envelope I. This wire may be positioned within the tube or envelope and it may have negligible resistance or it may have a substantial resistance of several hundred ohms. Each of the members 10 is also connected conductively to one of the members 4 by a wire or other conductor l2. In each of the members [2 is positioned acontact-type rectifier 13 If the wire H is positioned within the tube or envelope l the wires It will then not extend outwardly beyond the tube l but will be connected to the wire ll within the tube and correspondingly the rectifiers 13 may also be positioned within the tube or envelope Whatever the arrangement in this respect, the circuit will be substantially as shown.

The members 8 are, as shown, of more or less tunnel shape, and they comprise resistances or resistance members positioned within the envelope or tube l and in contact with the mercury or other metal 3 which forms the pool. Although these members are shown of funnel shape, other types of resistors may be substituted for them. Among the suitable types are those shown in our copending application Serial No. 139,942, which is filed of even date herewith. As thereshown, the resistors comprise resistance discs formed of carborundum or other material and they are solid, with a passage or perforation formed through them. Resistors of types other than these two may be used and the invention is not limited to the particular shape shown in the present application or in our aforesaid copending application. Resistors of this general type, however, have proven to be more efiective than those of other shapes, such as rods.

In the device of this invention, in any of the forms or arrangements suggested, the metal pool '3 will function as a source of electrons in an are operating on alternating current. The circuit and construction shown provides the necessary mechanism for initiating the discharge of electrons at the potential differences applied to th device; Operation has been found to be satisfactory even for currents as low as milli amperes provided the area of the pool 3 exposed to the interior of the envelope 1 is restricted as; for example, by the members 8 or by the corresponding members shown in our copending application above mentioned. We have operated arcs with pool-type electrodes of the type shown from alternating currents supplied at potentials of a few hundred volts in a circuit generally like that shown but without the rectifiers l3. With that modification, the potential is connected through the ballast l to the electrodes formed by the pools 3 at each end of the tube, and experience has shown that this suffices to initiate the arc during each half cycle of the alternating current and to maintain it until the potential falls below a critical value near the end of each half cycle.

Experience has shown that the potential difference on which the device will operate satisfactorily may be lowered substantially, however, by the use of a pair of rectifiers, such as the rectifiers l3 shown in the drawing. Any pair of devices such that the resistance offered to current passing in opposite directions differs may be used as rectifiers for the purpose indicated. One such device now known and sold on the market is Varistor.

As above pointed out, the circuit shown includes the rectifiers and their use reduces the part of the potential drop which occurs on the resistance material, such as the semi-conductive surface G of the members 8, within the tube at the end of the tube which is temporarily positive and thus throws a greater proportionate part of the potential drop across the resistance formed by the opposite surface 9 on the member 3 in the negative end which is, at the time, serving as a cathode. It is to be understood that when the device of the present invention is operated with alternating current, each electrode structure is alternately an anode and a cathode. Thus, the increased drop in the resistance material 9 at the positive end of the tube results in the early production of a cathode spot upon the pool of liquid metal 3.

In the modified form of Figure 2 the only change is that the wire which connects the coatings 9 is positioned wholly within the envelope and the rectifiers are also positioned within the envelope. Thus, a wire or conductor ill positioned wholly within the envelope is connected to each of the semi-conductive surfaces 8. As shown, this wire preferably includes portions l5 which are in extensive contact with the surfaces 9. At each end the wire M, at a point below the upper margin of the members 8, is provided with a portion i6 which extends into contact with the pool 3. Rectifiers E? are positioned in each of the wires or conducting members E5, and these rectifiers are the same in construction and purpose as the rectifiers l3 shown in Figure 1. From a comparison of the two figures, it is obvious that they include the same members and that the difference between the forms of the two figures is primarily that the wire, which connects the conductive surfaces 9, and the rectifiers are all located within the envelope.

The expression semi-conductor is used in this art today to describe materials which are relatively poor electrical conductors. Among the materials above mentioned carbon and carborundum are today properly described by the expression semi-conductors. Silicon and germanium are other presently known materials which would now be described by the expression semi-conductor as that expression is presently understood.

Although we have shown an operative form of our invention, it will be recognized that many changes in the form, shape and arrangement of parts can be made without departing from the spirit of the invention, and our showing is, therefore, to be taken as, in a sense, diagrammatic.

The use and operation of this invention are as follows:

With the circuit generally as shown in Figures 1 and 2, and with the device connected to a source of alternating current, the operation is normally substantially as follows;

That electrode which is negative momentarily will have a cathode spot established within it.

The electron current originating thereon passes through the residual gas and vapor contained within the envelope I and is collected by the opposite electrode at the end which is temporarily positive which, at that time, serves as an anode."

When the potential reverses polarity the cycle is repeated with the two electrodes interchanged so that the one which has acted as an anode now acts as a cathode and the one which has acted as a cathode new acts as an anode.

The use of the contact rectifiers causes a distribution of potential and current which causes the initiation of the cathode spot on the pool earlier in the cycle than would otherwise be the case in the absence of the rectifier. The device would work without a rectifier if the potential is high enough. Therefore, the presence of the rectifier permits operation at substantially lower potential,

The discharge tube itself contains no means for limiting the current, and this must be included in the external circuit as the current limiting ballast.

We claim:

1. In combination, an envelope of insulating translucent material substantially free from air and shaped to define a pair of pool retaining parts, a pool of metal, which is liquid at operating temperature, in each of said retaining parts, said envelope defining a passage from one pool to the other, conductors extending through said envelope, one in contact with each of said pools. means for electrically connecting said conductors to a source of alternating current, a current limiting ballast in said connecting means, restricting members positioned within said envelope, one above each of said pools, said members in contact with said pools, there being a passage past each member, each restricting member having a conductive portion thereon, and means for electrically connecting the conductive portions of said restricting members to each other and for connecting said conductive portions to said conductors.

2. In combination, an envelope of insulating translucent material substantially free from air and shaped to define a pair of pool retaining parts, a pool of metal, which is liquid at room temperature, in each of said retaining parts, said envelope defining a passage from one pool to the other, conductors extending through said envelope, one in contact with each of said pools, means for electrically connecting said conductors to a source of alternating current, a current limiting ballast in said connecting means, restrictin members positioned within said envelope, one above each of said pools, said members in contact with said pools, there being a passage past each member, the area of said passage at its point of contact with its respective pool being less than the total area of the pool, each restricting member havin a conductive portion thereon, and means for electrically connecting the conductive portions of said restricting members to each other and for connectin said conductive portions to said conductors.

3. In combination, an envelope of insulating translucent material substantially free from air and shaped to define a pair of pool retaining parts, a pool of metal, which is liquid at operating temperature, in each of said, retaining parts, said envelope defining a passage from one pool t the other, conductors extending through said envelope, one in contact with each of said pools, means for electrically connecting said conductors to a source of alternatin current, a current limiting ballast in said connecting means, restricting members positioned within said envelope, one

above each of said pools, said members in contact with said pools, there being a passage formed through each member, each restricting member 5. having a conductive portion, means for electrically connecting the conductive portions of said restricting members to each other and for connecting said conductive portions to said conductors, and rectifiers positioned in the connection from each restricting member to on of said conductors.

4. In combination, an envelope of insulating translucent material substantially free from air and shaped to define a pair of pool retaining parts, a pool of metal, which is liquid at operating temperature, in each of said retaining parts, said envelope defining a passage from one pool to the other, conductors extendin through said envelope, one in contact with each of said pools, means for electrically connecting said conductors to a source of alternating current, a current limiting ballast in said connecting means, restricting members positioned within said envelope, one above each of said pools, said members in contact with said pools, there being a passage formed through each member, the area of said passage at its point of contact with its respective pool being less than the total area of the pool, each restricting member having a conductive portion, means for electrically connecting the conductive portions of said restricting members to each other and for connecting said conductive portions to said conductors, and rectifiers positioned in the connection from each restricting member to one of said conductors,

5. In combination, an envelope of insulating translucent material substantially free from air and shaped to define a pair of pool retaining parts, a pool of metal, which is liquid at operating temperature, in each of said retaining parts, said envelope defining a passage from one pool to the other, conductors extending through said envelope, one in contact with each of said pools, means for electrically connecting said conductors to a source of alternatin current, a current limand'for joining the connections from said restrict ing members,

-7. In combination, an envelope of insulating material substantially free from air and shaped 10 through said envelope, one in contact with each iting ballast in said connecting means, restrict- I ing members positioned within said envelope, one above each of said pools, said members in contact with said pools, there being a passage formed through each member, the area of said passage.

at its point 01 contact with its respective pool being less than the total area of the pool,-each restricting member having a conductive portion, means for electrically connecting the conductive portions of said restricting members to each other and for connecting said conductive portions to said conductors, and rectifiers positioned in the connection from each restricting member to one of said conductors, said connecting means and said rectifiers being positioned outside of said envelope.

6. In combination, an envelope of insulating material substantially free from air and shaped to define a pair of pool retaining parts, a pool of metal, which remains liquid at normal operating temperature, in each of said pool retaining parts, said envelope defining a passage from one pool to the other, electrical conductors extending through said envelope, one in contact with each of said pools, members above each .pool, each adapted to restrict the exposed area of its respective pool, each of said restricting members comprising a part in contact with its respective pool and a part continuous therewith, out of contact with said pool and overlying and masking a portion of the upper surface of its pool, means for electrically connecting said conductors to a source of alternating current, and a plurality of means for joining said conductors to each other of said pools, members above each pool, each adapted to restrict the exposed area of its respective pool, each of said restricting members comprising a part in contact with its respective pool and a part overlying and maskin a portion of the upper surface of its pool, means for electrically connecting each restricting member to the other, means for electrically connecting said conductors to a source of alternating current, a plurality of means for electrically joining said eonductors to each other and for electrically joining the connections from said restrictin members, and a rectifier positioned in each of said last mentioned connecting means.

8, In combination, an envelope of insulating material substantially free from air and shaped to define a pair of pool retaining parts, a pool of metal, which remains liquid at normal operating temperature, in each of said pool retaining parts, said envelope defining a passage from one pool to the other, electrical conductors extending through said envelope, one in contact with each of said pools, members above each pool, each adapted to restrict the exposed area of its respective pool, each of said restricting members comprising a part in contact with its respective pool and a part overlying and masking a portion of the upper surface of its pool, means for electrically connecting each restricting member to the other, means for electrically connecting said conductors to a source of alternating current, a plurality of means for electrically joining said conductors and for joining the connections from said restricting members, and a rectifier positioned in each of said last mentioned connecting means, said rectifiers being positioned outside said envelope.

9. In combination, an envelope of insulating material substantially free from air and shaped to define a pair of pool retaining parts, a pool of metal, which remains liquid at normal operating temperature, in each of said pool retaining parts, said envelope defining a passage from one pool to the other, electrical conductors extending through said envelope, one in contact with each of said pools, members above each pool, each adapted to restrict the exposed area of its respective pool, each of said restricting members comprising a part in contact with its respective pool and a part overlying and masking a portion of the upper surface of its pool, each restricting member being provided with a semiconductive surface, means for electrically connecting the semi-conductive surface of each restricting member to that of the other, means for electrically connecting said conductors to a source of alternating current, and a plurality of means for electrically joining said conductors and for electrically joining the connections from said restricting members.

10. In combination, an envelope of insulating material substantially free from air and shaped to define a pair of pool retaining parts, a pool of metal, which remains liquid at normal operating temperature, in each of said pool retaink lng parts, said envelope defining a passage from one pool to the other, electrical conductors extending through said envelope, one in contact with each of said pools, members above each Dcol, each adapted to restrict the exposed area of. its respective pool, each of said restricting.

members comprising a part in contact with its respective pool and a part overlying and masking a portion of the upper surface of its pool, each. restricting member being provided with a semi-conductive surface, means for electrically connecting the semiconductive surface of each restricting member to that of the other, said means lying outside said envelope, means for electrically connecting said conductors to a source of alternating current, and a plurality- Qf. means for electrically joining said conductors and for joining the connections from said restricting members.

.11., In combination, an envelope of insulating material substantially free from air and shaped to: define a pair of pool retaining parts, a pool of metal, which remains liquid at normal operating temperature, in each of said pool retaining; parts, said envelope, defining a. passage from, one pool to the other, electricalconductorsextending through said envelope, one in contact with each of said pools, members above each pool, each. adapted to restrict the exposed area: of its respective pool, each of said restrict.- mg members comprising a part in contact with its respective pool and a part overlying and masking a portion of the upper surface of its pool, each: restricting member being provided with a. semi-conductive; surface, means; for electricallyconnecting the semi-conductive surface of each restricting member to that oi the other, means forelectrically connecting saidconductors to a source of alternating current, a current limiting ballast, means in said connectingmeans, and a plurality oi means for electrically joining; said conductors and for joining the connections: from said: restricting members.

12. In combination, an envelope of, insulating; material substantially free fromair and shaped to, define, a pair of pool retaining: parts; a pool of metal, which'remains liquidat normal operating; temperature, in each of said pool retaining parts, said envelope defining a passage from. one.

pool to the other, electrical conductors extendingthrough said envelope, one in 'contact. with each of said: pools, members. above eachpool, each, adapted: to restrict the. exposed area of. its. respective; pool. each of said restricting: members:

comprising a. part incontact with; its; respective pool and apart overlying. and masking a. pars. tion. ofthe upper surface: of. its: pool, each. restricting: member being; provided with a semi.- conduetive; surface, means for; electrically corrnecting: the; semi-conductive surfaces of each.-

trically joining said conductors and for joiningtheconnections-from said restricting members.

and a, rectifier positioned} in each of. said last.- rnentioned. connecting means, said. rectifiers be;- ing positioned outside said: envelope,

13. In; combination, an envelope of: insulating translucent. material substantially; free: from; air

and shaped" to define a pair of pool; retaining; parts, a: pool of metal, which, is: liquid at; operatiing temperature. int eachf saidretaminez'n rts said envelope defining a passage from one pool to theother, conductors extending through said envelope, one in contact with each of said pools, means for electrically connecting said conductors. to a source of alternating current, a current limiting ballast in said connecting means, resistance elements within said envelope, one above each ofsaid'pools, said resistance members in contact with said pools, and means for electricallyconneoting to each other parts of said two resistance members which are above said pools.

14-. In combination, an envelope of insulating translucent material substantially free from air and shaped to define a pair of pool retaining parts, said parts being shaped to restrict the exposed surface area of a pool of metal, which is liquid at, operating temperature, in each of said retaining parts, said envelope defining a passage from one. pool to the other, conductors extending' through said envelope, one in contact with each.- of said pools, means for electrically connecting said conductors to a source of alternating current, a current limiting ballast in said connecting means, resistance elements within said. envelope, one. above each of said pools, said resistance members in contact with said pools, and means for electrically connecting to each ther parts of said two resistance members which are above. said pools.

15. In combination, an envelope of insulating translucent material substantially free from air and containing a pressure of not less than sev eral hundred microns of inert gas, said envelope shaped to define a pair of pool retaining parts, a pool of metal, which is liquid at the operating temperature, in each of said retaining parts, said envelope defining a passage from one pool to the other, conductors extending through said envzelope, one in contact with each of said pools, means for electrically connecting said conductors-to asource of alternating current, a current limiting ballast. in said. connecting means, resistanceelements with surfaces of resistance material freely exposed to space within said envelope, one of said resistance elements in contact with each; of said pools, means for electrically connesting to each other parts or" two said resistance members which. are above. said pools.

156. In combination, an envelope of insulating translucent material substantially free from air and shaped to define a pair of pool retaining parts, a pool of metal, which is liquid at the operating temperature,.in each of said retaining partssai'd' envelope defining a passage from one pool to the other, conductors extending through said envelope, one in contact with each of said.

pools, means for electrically connecting said conductors tola source of. alternating current, a currentlimiting ballast insaid conducting means, resistance elements with surfaces of resistance material freely exposed to space within said envelope, one of said resistance elements in contactwith each" of said pools, electrical terminals not indirect contact with the pools on each of said resistance members, electrical connection from each terminal passing through a contact rectifier to that metal pool with which the resistance element is in. contact, and means for electrically connecting terminals of the two resistances toeach other.

L7. Incombination, an envelope of insulating translucent-material substantially free from air and, shaped to: define a. pair of. pool retaining parts, said parts being shaped to restrict the exposed surface area of a pool of metal, which is liquid at operating temperature, in each of said retaining parts, said envelope defining a passage from one pool to the other, conductors extending through said envelope, one in contact with each of said pools, means for electrically connecting said conductors to a source of alternating current, a current limiting ballast in said conducting means, resistance elements with surfaces of resistance material freely exposed to space within said envelope, one of said resistance elements in contact with each of said pools, electrical terminals not in direct contact with the pools on each of said resistance members, electrical connection from each terminal passing through a contact rectifier to that metal pool with which the resistance element is in contact, and means for electrically connecting terminals of the two resistances to each other.

18. In combination, an envelope of insulating translucent material substantially free from air and shaped to define a pair of pool retaining parts, a pool of metal, which is liquid at the operating temperature, in each of said retaining parts, said envelope defining a passage from one pool to the other, conductors sealed through said envelope, one in contact with each of said pools, means for electrically connecting said conductors to a source of alternating current, a current lirni iting ballast in said conducting means, resistance elements with surfaces of resistance material freely exposed to space within said envelope, one of said resistance elements in contact with each of said pools, electrical terminals not in direct contact with the pools one on each of the resistance members, electrical conductors from each of said terminals sealed through said envelope, said conductors electrically connected to each other outside of said envelope.

19. In combination, an envelope of insulating translucent material substantially free from air and shaped to define a pair of pool retaining parts, a pool of metal, which is liquid at the operating temperature, in each of said retaining parts, said envelope defining 'a passage from one pool to the other, conductors sealed through said envelope, one in contact with each of said pools, means for electrically connecting said conductors to a source of alternating current, a current limiting ballast in said conducting means, resistance elements within said envelope, one in contact with each of said pools, electrical terminals not in direct contact with the pools, one on each of the resistance elements, electrical conductors from each of said terminals sealed through said envelope, said conductors electrically connected to each other outside of said envelope, and said conductors connected to the conductors in contact with the pools by means of contact rectifiers located outside of said envelope.

20. In combination, an envelope of insulating material substantially free from air and shaped to define a pair of pool retaining parts, a pool of metal, which is liquid at operating temperature, in each of said retaining parts, said envelope defining a passage from one pool to the other, conductors extending through said envelope, one in contact with each of said pools, means for electrically connecting said conductors to a source of alternating current, a current limiting ballast in said conducting means, semi-conducting funnel-shaped members above each pool, each adapted to restrict the area of its pool exposed to the electrical discharge, each of said funnels comprising a part in contact with its respective pooland overlying and masking a portion of the upper surface or" its pool, an electrical terminal at the large end of each semi-conducting member, means for electrically connecting the said terminals to each other inside of the envelope, and means for electrically connecting each terminal through a contact rectifier to the pool, the physical position of said contact rectifier being in the space bounded by the pool, the funnel, and that portion of the envelope surrounding the funnel.

21; In combination, an envelope of insulating translucent material substantially free from air and shaped to define a pair of pool retaining parts, a, pool of metal, which is liquid at the operating temperature in each of said parts, said envelope defining a passage from one pool to the other, conductors extending through said envelope, one in contact with each of said pools, means for electrically connecting said conductors to a source of alternating current through some current limiting device, resistance elements within said envelope and in contact with each pool, said elements electrically connected to each other, the current through said resistance elements initiating a cathode spot when a pool becomes negative, the potential distribution attending the flow of current in said resistance elements causing the transfer of the electron current originating at the spot through the gas in said envelope to the electrode which is temporarily positive.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 803,836 Lunt Nov. 7, 1905 1,178,542 Skaupy Apr. 11, 1916 1,889,079 Sperti Nov. 29, 1932 2,006,466 Ludwig July 2, 1935 2,020,736 Pirani et al Nov. 12, 1935 2,157,923 Slepian May 9, 1939 2,160,583 Cage May 30, 1939 2,215,804 West Sept. 24, 1940 2,218,386 Smith Oct. 15, 1940 2,495,831 Warmoltz Jan. 31, 1950 FOREIGN PATENTS Number Country Date 461,380 Germany June 22, 1928 59,321 Holland Apr. 15, 1947