US1661579A

US1661579A - Bulb rectifier

Info

Publication number: US1661579A
Application number: US578131A
Authority: US
Inventors: Earl H Rollinson
Original assignee: Cooper Hewitt Electric Co
Current assignee: General Electric Vapor Lamp Co
Priority date: 1922-07-28
Filing date: 1922-07-28
Publication date: 1928-03-06
Anticipated expiration: 1945-03-06

Description

March 6, 1928.

E. H. ROLLINSON BULB RECTIFIER Filed Ju1y28. 1922 2 ShootvSheot 1 March 6, 1928. 7 1,661,579

E. H. ROLLINSON BULB RECTIFIER Filed July 28, 1922 2 shuts-shun 2 MWM lA/VE/YTOR A T ORIV Patented Mar. a, 1928.

UNITED STAT ES PATENT OFFICE EARL n. EoLLnisoiI, or LYONS rams, NEw'JEnsEY, assrouoza To 000mm HEWITT ELECTRIC COMPANY, OF EOBOKEN, NEW JERSEY, A CORPORATION or NEW JERSEY.

BULB REcTI'EIEE.

Application filed July 28, 1922. Serial No. 578,131.

In my prior application, Serial No. 461, 886, now Patent 1,591,185, filed April 16, 1921, I have described an improved arc rectifier with a rectifier bulb, wherein the cathode is formed. from a closely I coiled filament of tungsten, from which various leads are described as carrying A. C. to be rectified. The bulb is exhausted of air and usually filled with some gas of the argon group. In the development and use of the rectifier described in said application, the tungsten filament has frequently burned out. In experimenting with bulbs of this type, I have discovered that the tungsten filament is not essential to the working of the rectifier; indeed I am able to operate the bulb after the filament has been completely ruptured equally as well as when the filament is intact. I am therefore able to use bulbs in which the filament has broken down by the system which I will fully describe in the following specification.

The object of my invention, therefore, is to construct a rectifier system wherein the cathode rods are unconnected and a high otential spark between them serves as the initial ionizing agent, and thereafter the operation of the system continues either with or without the high potential spark.

A further object of my invention is to utilize exhausted rectifier bulbs, i. e. bulbs in which the tungsten filament is ruptured, which under the system which I have devised, last almost indefinitely, and when the cathode rods have been burned down to mere stubs, they may be readily renewed by qpening up the bulb. Since the ionizlng o the gas within the bulb is produced by the spark between the cathode rods, I prefer to protect them by covering their free ends with small carbon caps which have suflicient area to dissipate any destructive heat which may develop from the spark. A further objectpf my invention is to construct new bulbs with a supplemental or service cathode and utilize, what has been hitherto considered the Similar reference numerals refer to like parts throughout the specification and draw- As set forth in my above named prior application, the life of the rectifier bulb above, using the tungsten filament had theretofore been limited to about 800 hours, but with the improvements set forth in the said application, the life of the bulb is lengthened to about 1200 hours and in some cases considerably longer. By the improvements of my present invention, I am able to prolong the life of the bulb almost indefinitely, by

reason of the fact that the perishable part or element which has hitherto been considered as necessary to the rectification of A. C. is omitted and, the system of wirin slightly modified to correspond; also a hi frequency spark coil is introduced into t lde wiring system for the purpose of starting its operation.

In Fig. 1, the transformer T, rectifier bulb 1, high frequency coil H. (l, reactance coil R. (1., storage battery B, ammeter A, and solenoid circuit breaker 2 are of the usual type with the exception that in the bulb 1, the usual tungsten filament connecting the cathode leads 3, 4: is omitted and carbon caps 3, 4 are mounted thereon. The leads 3, 4 together constitute a cathode element which is introduced into the tube by a re-entrant stem :12, in which they are sealed in substantially parallel alignment with each other. Because of this parallel mounting, the spark distance between the leads remains approximately constant in length, as they burn down in use. The bulb may be originally constructed without the filament, or bulbs in which such filament has broken down and which have hitherto been discarded as useless may be used. The trans former T has the usual secondary 5 and a tertiary winding 6; the first being provided with a number of taps 7, 8 at each end for current regulation, while the tertiary 6 is of small capacity usually about 10 volts, and is utilized only as a starting means.

The wiring diagram may be described as follows: Starting from one of the taps 7 the wire 9 leads to the reactance coil R. 0., thence wire 10 leads to a terminal of the battery B, from the other terminal of which the wire 11 leads through the ammeter A to the bulb anode 12. From one of the taps 8 at the other end of the secondary 5, the wire 13 leads to the coil of the circuit breaker 2, from which the wire 14 leads to the cathode lead 3. If desired a small switch 15 may be located between the

wires

13 and 14 in order to short circuit the circuit breaker 2. The carbon caps 3, 4' are mounted upon the free ends of the cathode rods 3, 4 and by their large surface, serve to dissipate any destructive heat which might develop in the rods due to the spark.

The diagram for the starting or high frequency coil may be described as follows The wire 16 leads from one end of the tertiary winding 6 to one of the contacts 17 of the circuit breaker 2; from the other contact 18 of which the wire 19 leads to and is connected with the armature side of the high frequency coil H. 0., from the primary of which the wire 20 leads back to the other end of the transformer tertiary winding 6. The secondary of the high frequency coil C. is connected by the wire 21 through the spark gap 22 to the cathode lead 3, and the wire 23 connects the other cathode lead 4 through a spark gap 24 with the wire 19.

A comparison of the diagram shown in Fig. 2 will show that it is identical in all respects with that shown in Fig. 1 with the single exception that the wire 25 connects the wires 11 and 21, through the spark gap 26; the diagram shown in Fig. 3 is identical in all respects with Fig. 1 except that the cathode rods 3, 4 are connected solely into the secondary circuit of the high tension coil, H. C. while a main cathode 27 is located directly between the rods or leads 3, 4 and connected by wire 14 with the coil of the circuit breaker 2. This amounts structurally, only to the dividing of the cathode lead 3 into two elements one of which is connected to the transformer secondary and the other to the high frequency coil secondary whereas in the other diagrams both of those secondaries are connected to a single cathode lead. v

The operation of the device is as follows: Upon closing the primary of the transformer T into the main or supply circuit, the high frequency coil H. C. is immediately supplied with current coming from the tertiary winding 6. The current therefrom taking the following path: by way of the wire 21, spark gap 22, cathode rod 3 across the cathode rod 4, thence by wire 23, spark gap 24 and wire 19 back to the high freuency coil secondary. The high potential tius produced in the high frequency coil, will reduce s arking at the gaps 22 and 24 and etween-t e cathode rods 3 and 4, which latter will result in ionizing the gas within the bulb 1. It may be stated at this point that the gaps 22 and 24 not only intensify the ionizing spark between the cathode rods 3 and 4, but serve also to insulate the high frequency coil H..C. from the transformer secondary 5. A peculiar hcnomenon develops as the spark is pro uccd across the gap between the cathode rods 3 and 4. The spark first ap cars at the base of said leads, t at is, at tie points where they emerge from the glass support X, and when potential is supplied between the anode 12 and the rods 3 or 4, the spark creeps up to the free ends of said rods where it remains. The spark thus produced, between the cathode leads or rods 3 and 4, ionizes the inert gas within the bulb and immediately electrons begin to flow across between the anode 12 and the cathode 3, thereby establishin the rectifying circuit through the batte by way of the

wires

9, 10, 11, 13 and 14. Thereafter the rectification roceeds continuously until the battery B is c iarged.

It should be noted that the rectifyin circuit just described, includes the smal circuit breaker 2; immediately upon the starting of the rectifying current, this circuit breaker is opened at the oints 17, 18, thereby cutting out the high requency coil H. C. It may be thought, at first glance, that the opening of this circuit, eliminatin as it does the spark between the points of t e cathode rods 3 and 4 would immediately sto the operation of the rectifying circuit. uch, however, is not the case for it is only necessary to start the rectification by producing the spark across the cathode leads 3 and 4, whereupon the point of the cathode rod 3 is heated, by the bombardment of the electrons flowing, and the rectif ing current, whereby the gas within the bulb becomes ionized; thereafter this bombardment of electrons between the point of the rod 3 and the anode 12 will be suflicient to maintain the ionizing effect which is all that is necessary for continuous rectification.

If, for any reason, the rectifying current to the battery B should cease temporarily as by the opening of the circuit, the solenoid circuit breaker 2 would be immediately deenergized, its core would drop, and the hi h frequency coil primary would at once ie thrown into circuit with the tertia winding 6, when of course, the spark etween cathode rods 3 and 4 would again be produced and rectification would again start upon the reclosing of the open circuit. This renders the device automatic and self-starting so long as the supply circuit through the primary of the transformer T is closed.

It is not essential that the high frequency coil H. C. be cut out of operation by the circuit breaker 2, since rectification would proceed just the same if said circuit breaker produced between the cathode rods.

were omitted from the system and the

wires

16 and 19 directly connected. I may accomplish such a result by closing the switch 15, thereby short circuiting the circuit breaker 2.

It will be noted that the diagram shown in Fig. 2 is identical with that shown in Fig. 1 in all of its parts, with the single exception that the wire 25 connects the wires 21 and 11 with the spark gap 26 interposed therein. By this slight modification, I am able to produce ionization between the anode 12 and cathode 3 as well as between the cathode rods 3 and 4.

With the rectifier as thus far described, I am able to use exhausted bulbs in which the usual tungsten filament has broken down in use, inasmuch as I produce the ionizing efiect not by heat generated in any such filament or even in the cathode rods, but by the spark In this manner, ionization is only initiated by the spark produced between said rods, but such ionization is maintained by the are produced between the cathode 3 and anode 12, and this Whether or not the spark between the cathode rods 3 and 4 is maintained. The means described effectively produces the spark be tween the cathode rods and after ionization begins, the maintenance of said spark is no longer essential. vSince the ionization is continued by the arc spanning the gap be-.

tween the anode 12 and the cathode rod 3, this feature naturally leads to the development of the form of bulb illustrated in Fig. 3. Here, the two rods 3 and 4 are connected up in circuit with the secondary of the high frequency coil and the spark is produced between said rods in the manner as above described. Interposed between the two rods 3 and 4, is the service cathode rod 27, which is connected up by the wire 14 in exactly the same manner as above described in connection with Figs. 1 and 2. The point of this cathode rod 27 is located directly'in the path of the spark between the points of the rods 3 and 4 and when potential is applied be tween the anode 12 and cathode rod 27, the

ionization produced causes current to flow to the service cathode rod 27, whereas, in Figs. 1 and 2 the rod 3 serves the double purpose, that is to say, as a cathode rod and also as a spark gap terminal. After rectification begins, the operation will be continuous, whether the high frequency coil H. C. is kept in circuit by closing the switch 15 or automatically cut out by the opening of said switch. In order to still further intensify the spark between the rods 3 and 4:, I may insert a condenser C across the terminals of said cathode rods as shown in Figs. 1 and 3.

l/Vhile it has been the custom to fill glass rectifier bulbs with argon gas, yet I find that any of the inert gases such as neon gas or nitrlogen gas will serve the purpose equally wel In connection with Fig. 2, I have described the wire 21 and the wire 11 as spanned by the wire 25 and spark gap 26. With this form, a spark may be produced between the anode 12 and the electrode 4, as the initial ionizing agent.

The cathode caps 3 and 4 shown in Figs. 4 to 7 which are mounted upon the free ends of the cathode rods 3, 4 are made of carbon and as above indicated they serve to dissipate the heat due to the are between said cathodes and the anode 12. They also enable me to utilize other materials for cathode rods than the usual tungsten, as for example, molybdenum, tantalum, or some of the ot er less refractory of the metals. In Figs. 4: and 5, I have shown the caps as of a cup shape, while in Figs. 6 and 7 they are shown as fluted resembling a small pinion. The form or shape however, is quite immaterial so long as a suitable radiating surface is afforded.

I claim:

A thermionic rectifier comprising a tube provided with a re-entrant stem, an anode and a cathode element, the latter comprising spaced, substantially parallel conductors mounted on said stem and designed to establish an exciting are from one to the other.

EARL H. ROLLINSON.