US2294623A - Low voltage gaseous tube lamp and electrical circuits therefor - Google Patents

Description

p 1942- P. F. LEBRUN 212947623 LOW VOLTAGE GASEOUS TUBE LAMP AND ELECTRICAL CIRCUITS THEREFOR Filed Jan. 25, 1940 3 Sheis-Sheet l ATTORNEY Sept. 1, 1942. F. F. LEBRUN 2,294,623

LOW VOLTAGE GASEOUS TUBE LAMP AND ELECTRICAL CIRCUITS THEREFOR Filed Jan. 25, 1940 5 Sheets-Sheet 2 ATTORNEY Sept. 1, "P LEBRUN LOW VOLTAGE GASEOUS TUBE LAMP AND ELECTRICAL CIRCUITS THEREFOR Filed Jan. 25, 1940 3 Sheets-Sheet 3 /ZM MW ATTORNEY Patented Sept. 1, 1942 LOW VOLTAGE GASEOUS TUBE LAMP AND ELECTRICAL CIRCUITS THEREFOR Paul Francois Lebrun, Astoria, N. Y., assignor of one-half to Peter Synek, Astoria, N. Y.

Application January 25, 1940, Serial No. 315,489

11 Claims.

This invention relates to low voltage gaseous tub lamps and particularly to starting devices for such lamps.

The principal object of the invention is to provide an electrically operated gaseous tube lamp with associated starting and operating electric circuits.

Another object of the invention is to provide an electric gaseous tube lamp that may be started and operated on low voltages.

A further object is to provide an electric gaseous tube lamp starting device operable with lamps of greater length than previously deemed possible.

A still further object is to provide a gaseous tube lamp operable on low voltages and under cold climatic conditions.

A still further object is to provide a gaseous tube lighting circuit which is not only easy to start under cold climatic conditions but also economical during operation.

Other objects will be apparent from a consideration of this specification and the drawings.

Heretofore gaseous tube lamps have been restricted in their installations not only as to their length but also as to the climatic conditions under which they may operate successfully. The principal difficulty met with in the use of lamps of this type is that step up voltage transformers are required for their operation particularly when the lamps are subjected to low temperatures. Extensive use of these lamps has not been made because of the diificulties of providing the high voltages necessary for starting them unless their lengths be short. The average length of such lamps previously in operation was approximately two feet for 115 volt. With the lamps and the associated circuits disclosed in this specification the length of lamps has been increased to six feet and more and their operation has been successful under colder climatic conditions than has heretofore been possible and only 110 to 120 volt current has been necessary to operate them.

In th drawings:

Fig. 1 is a cross-sectional view of an electric gaseous lamp;

Fig. 2 is an enlarged view of one end of the lamp showing the mounting of a heating element and an anode in the ends of the tube;

Fig. 3 is a diagrammatic sketch of the tube and associated starting and operating circuits;

Fig. 4 is a diagrammatic sketch of a tube and modified starting and operating circuits;

Fig. 5 is a plan view in section of the circuit breaker in the starting circuit;

Fig. 6 is a sectional elevation of the circuit breaker shown in Fig. 5; and

Fig. 7 is a cross-section of the circuit breaker taken on the line 1'| of Fig. 6.

The lamp consists of a glass tube l sealed at each end and in each end of which is mounted a heating filament 2 supported on wires 5, 5 that extend through the ends of the tube and are connected to leads 6, 6. The filaments are made preferably of fine tungsten wires twisted together, but any other durable metal may be used. Coiled spirally around the filaments 2 are anodes 3, 3 made preferably of some oxide coated wire. The anodes are connected to their respective filaments at only one point, 4, 4. Around the anodes and th filaments are mounted tubes 1, I made of some heat conducting metal for the physical protection of the filaments and anodes.

The tubes are exhausted of their air and are sealed under a vacuum or they may be filled with a gas that is easily ionized. The tube is coated, either on the inside or the outside with a fluorescent material which emits light under the stimulation of the flow of current between the electrodes.

Referring particularly to Figure 3, electric power is supplied by leads 8, 8 through control switch 9. One side of the power leads is connected by wire In through choke coil H to one end of the primary l2 of transformer IS. The other side of the power leads is connected through wire l5 to a conventional thermal circuit breaker l6 and thence to the other end of primary I2 by wire H. The secondaries M of transformer l3 are connected to the heating filaments 2,2 by leads 6, 6.

Lead l9 connects one anode 3 to one power lead 8 and to one side of circuit breaker I6. Lead l8 connects the otheranode 3 to the other power lead 8 through the choke coil l l and to the other end of the primary [2. This end of primary l2 could be connected to lead I0, but I prefer to connect it directly to the anode 3.

Across the leads l0, I5 is connected condenser 20 and resistance 2| constituting a heating element for the circuit breaker l6, as will be described later.

The starting of the tube is as follows: When switch 9 is closed, electric power is made available to transformer I3 through choke coil II and thermal circuit breaker l6. Current also flows through condenser 20 and resistance 2|. Currents from the secondaries of transformer l3 flow through the filaments 2, 2 and heat up the tube and gas therein. After a definite period of time,

that is, when the tube and gas therein have become heated, the thermal circuit breaker coil is also heated to a predetermined oper ve perature and the circuit through the primary of the transformer I3 is broken. While the circuit is broken, high Voltage transitory currents are generated in the primary and are impressed upon the filaments and anodes. It is well known that when an electric circuit is broken, high voltage transitory currents are induced, the voltage depending upon the interval of time of the actual breaking of the circuit and the electrical characteristics of the circuit. With the normal time or operation of a conventional thermal-electric circuit breaker in the circuit as described, it has been found that suflicient voltage is induced that, when applied to the anodes, a flow of current is established between the anodes. Once this flow is established the line voltage impressed on the anodes is suflicient to maintain th flow.

Resistance 2| is placed near the heating coil of circuit breaker Hi and is connected across leads I and I5. It supplies sufiicient heat to the thermal circuit breaker such that once the circuit breaker is opened, it will be retained in its open position during the operation of the lamp. It will be noted that during the operation of the tube the only current consumed that is not turned directly into light is the small current through the condenser and the heating resistance 2|, which is negligible as far as a power loss is concerned as the condenser returns to its circuit practically all of the power absorbed by it. At the same time, it will be noted, the condenser improves the power factor of the circuit as a whole.

A modification of the arrangement shown in Fig. 3 is disclosed in Fig. 4. During the starting stage, one side of the power leads 3 is connected to one side of the primary l2 of transformer 3 through conductor Ill, electromagnetic coil 24, lead l and choke coil The other side of the power source 8 is connected to the other end of primary |2 by conductor l5, electromagnetic circuit breaker 22, hereinafter described, and lead Connected between lead l1 and one end of the choke coil is electromagnetic coil 25 and a conventional thermal circuit maker 23. Electromagnetic coils 24 and 25 are placed in operative position near electromagnetic circuit breaker 22 that their fields may cause the opening of the circuit breaker and once the primary circuit is broken, the circuit breaker will remain in its open position.

The other parts of the circuit in Fig. 4 are identical with those shown in Fig. 3.

The starting of the lamp in the modified circuit is as follows: Upon the closing of switch 9 electric power is delivered to primary l2 by lead l5, circuit breaker 22, lead l1 and lead l8, choke coil lead l0, electromagnetic coil 24 and lead Ill. The ohmic resistance of the various elements of this circuit are such that the currents through coils 24 and 25 are not enough to create a field strong enough to operate circuit breaker 22. It will thus be seen that the heating elements 2, 2, receive current from the secondaries l4, as previously described.

During this time, the small current through circuit maker 23 heats up its bimetal contactor arm until its contacts are closed, short circuiting its heating element and lowering its resistance, thus permitting a greater current to flow through coil 25. With the circuit maker in its closed position, the fields of coils 24 and 25 are sufreturns to its open position and no current will flow through coil 25.

The circuit breaker 22 consists of a tube 3| in which is mounted a base 32 made of some insulating material. On this base 32 is mounted a stiif wire 34, preferably made of tungsten or other heat resisting metal. Contact 33 is mounted at the end of wire 34. Wire 34 is secured to the base by rivets 35 and. is connected to a lead 36 through the end of the tube.

The other contact 31 consists of an electromagnetic responsive material, .such as soft iron, and covered with a spark resisting metal such as silver or platinum. Contact 31 is supported in physical contact with contact 33 on a spring consisting preferably of two wires 38, 39 made preferably of some heat resisting and nonmagnetic metal such-as tungsten. A sheet of other spring non-magnetic material may be substituted for these wires. The wires 38, 39 are held in position by rivet 40 and. are connected to lead 4| which extends through the end of the tube 3|.

Mounted on base 32 is a second spring 43 formed as a loop and held in position by rivet 44. This spring in its normal position, that is, when the contacts 33 and 31 are together, extends at an angle to the base 32 and is so placed that when the spring wires 38 and 39 are deflected by a magnetic field forcing contact 31 away from contact 33, contact 31 resiliently rests against spring 43. It will thus be seen that when the circuit breaker is in its open position, any vibrations in the springs 38, 39 are damped out by the spring 43 making the circuit breaker noiseless even when operating on alternating current.

A spring 45 secured by rivet 44 is in resilient contact with tube 3| to keep one end of base 32 in position. The other end of base 32 is held in position by the leads 36 and 4|. The tube 3| is preferably sealed under a vacuum, but it may be filled with an inert gas.

The circuit breaker is operated by an electromagnetic coil connected in the circuit desired to be broken, the core of which coil is placed in operative juxtaposition to the electromagnetic responsive element 31.

It is obvious that various changes may be made by those skilled in the art in the details of the embodiment of the invention shown in the drawings and described above within the principle and scope of the invention as expressed in the appended claims.

I claim:

1. In combination, a gaseous tube electric lamp including a. heating element and an anode at each end of said tube the heating elements and the anodes being respectively connected together at one point, a choke coil, leads connecting said anodes with a, source of electric power the said choke coil being connected in series in one of said leads, a transformer consisting of a primary and two secondary coils, the said coils being conductively separate, leads connecting the said secondaries respectively with the said heating elements, leads connecting the said primary with said power, one of said leads being through the said choke coil, and means for automatically disconnecting the other lead from said power after an interval of time,whereby the said heating elements heat up the said tube and whereby the high voltage transitory currents produced by said disconnecting are applied to said anodes.

2. In combination, a gaseous tube electric lamp including a heating element and an anode at each end of said tube the heating elements and the anodes being respectively connected together at one point, leads connecting said anodes with a source of electric power, a transformer consisting of a primary and two secondary coils, the

said coils being conductively separate, the primary being connected cross said leads in shunt with the anodes, leads connecting the said secondaries respectively with the said heating elements,

leads connecting the said primary with said power and the said anodes, and means for breaking the said primary shunt connection, whereby the said heating elements heat up the said tube and whereby the high voltage transitory currents produced by said disconnecting are applied to said anodes.

3. In combination, a gaseous tube electric lamp including a heating element and an anode at each end of said tube the heating elements and the anodes being respectively connected together at one point, a choke coil, leads connecting said anodes with a source of electric power, the said choke coil being connected in series in one of said leads, a transformer consisting of a primary and two secondary coils, the said coils being conductively separate, the primary being connected across said leads in shunt with the anodes and between the anode and choke coil in the said one lead, leads connecting the said secondaries respectively with the said heating elements, means for automatically disconnecting the said primary from said power after an interval of time, and means for maintaining the said disconnecting means in a disconnected condition.

4. In combination, a gaseous tube electric lamp including a heating element and an anode at each end of said tube the heating elements and the anodes being respectively connected together at one point, a choke coil, leads connectconnect said primary from said power after an interval of time, and means for maintaining the circuit breaker in an open position after it has opened its circuit.

5. In combination, a gaseous tube electric lamp including a heating element and an anode at each end of said tube the heating elements and the anodes being respectively connected together at one point, a choke coil, leads connecting said anodes with a source of electric power the said choke coil being connected in series in one of said leads, a transformer consisting of a primary and two secondary coils, the said coils being conductively separate, leads connecting the said secondaries respectively with the said heating elements, a time delay thermal circuit breaker, leads connecting the said primary in shunt across the first mentioned leads, the said circuit breaker being connected in series in one of said last mentioned leads and operable to disconnect said primary from said power after an interval of time, an impedance and a heating coil, the said heating coil being mounted in juxtaposition with said circuit breaker, and leads connecting said impedance and said heating element in series and to said power, whereby the said circuit breaker is held in its open position after it breaks its circuit.

6. In combination, a gaseous tube electric lamp including a heating element and an anode at each end of said tube the heating elements and the anodes being respectively connected together at one point, a choke coil, leads connecting said anodes with a source of electric power the said choke coil being connected in series in one of said leads, a transformer consisting of a primary and two secondary coils, the said coils being conductively separate, leads connecting the said secondaries respectively with the said heating elements, a time delay thermal circuit breaker, leads connecting the said primary in shunt across the first mentioned leads, the said circuit breaker being connected in series in one of said last mentioned leads and operable to disconnect said primary from said power after an interval of time, a, condenser and a heating coil, the said heating coil being mounted in juxtaposition with said circuit breaker, and leads connecting said condenser and said heating element in series and to said power, whereby the said circuit breaker is held in its open position after it breaks its circuit.

7. In combination, a gaseous tube electric lamp including a heating filament and an auxiliary anode at each end of said tube the said filaments and anodes being respectively connected together at one point, a choke coil, an electromagnetic circuit breaker including an electromagnetic coil juxtaposed thereto, leads connecting said anodes with a source of electric power, the said choke coil and the said coil being connected in series with each other and in series in one of said leads, a transformer consisting of a primary and two secondary coils, the said coils being conductively separate, leads connecting said secondaries respectively to said filaments, a thermal delay circuit maker, a second electromagnetic coil juxtaposed with said first coil, a lead connecting one end of said primary to one contact of said circuit breaker, a lead connecting the other contact of said circuit breaker to one of said anodes and to one side of said power, a lead connecting the other end of said primary to the other of said anodes and to one end of said choke coil, and a lead including the said second coil and circuit maker in series therewith connecting the said end of said choke coil to the said end of said primary, whereby the action of said circuit breaker is delayed for an interval of time and upon its operation to its open position it remains in its open position.

8. A gaseous tube electric lamp, including a heating filament and an anode at each end of said tube the heating filaments and the anodes being respectively connected together at one point, a transformer consisting of a primary and two secondary coils, the said coils being conductively separate, leads connecting said secondaries respectively to said filaments, a lead connecting one of said anodes to one side of a source of electric power, a power control means, an electromagnetic coil, a lead connecting the other of said means and the other end of said primary adapted to augment the magnetic field of said coil to the said predetermined value after an interval of time.

9. A gaseous tube electric lamp, including a heating filament and an anode at each end of said tube the heating filaments and the anodes being respectively connected together at one point, a transformer consisting of a primary and two secondary coils, the said coils being conductively separate, leads connecting said secondaries respectively to said filaments, a lead connecting one of said anodes to one side of a source of electric power, a power control means, an electromagnetic coil, a lead connecting the other of said anodes to one end of said primary and to the other side of said power through successively the said power control means and the said coil, a second electromagnetic coil juxtaposed with first coil, an electromagnetically operated circuit breaker juxtaposed said coils and adapted to open its contacts upon the rise of the magnetic field of said coils to a predetermined value, and means connected to said second coil to bring the said magnetic field to the said predetermined value after an interval of time.

10. A gaseous tube electric lamp, including a heating filament and an anode at each end of said tube the heating filaments and the anodes being respectively connected together at one point, a transformer consisting of a primary and two secondary coils, the said coils being conductively separate, leads connecting said secondaries respectively to said filaments, a lead connecting one of said anodes to one side of a source of electric power, a power control means, an electromagnetic coil, a lead connecting the other of said anodes to one end of said primary and to the other side of said power through successively the said power control means and the said coil, a second electromagnetic coil juxtaposed with first coil, an electromagnetically operated circuit breaker juxtaposed said coils and adapted to open its contacts upon the rise of the magnetic field of said coils to a predetermined value, and a thermal delay circuit maker connected in series with said second coil across the said primary, whereby the magnetic fields of the two coils are brought to said predetermined value after an interval of time.

11. In combination, a gaseous tube electric lamp including a heating filament and an anode at each end of said tube, the heating elements and the anodes being respectively connected together at one point, a source of electric power, leads connecting the anodes to opposite sides of said source, a transformer having a primary and two secondary coils, the said coils being conductively separate each secondary being connected in series with one heating filament and the primary being connected across the said leads in shunt with the electrodes, a circuit breaker in said shunt circuit between the primary and one of said leads, and power control means in the other of said leads between the shunt connection and the power source.

PAUL FRANCOIS LEBRUN.

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