US1869567A

US1869567A - Full wave rectifier

Info

Publication number: US1869567A
Application number: US210809A
Authority: US
Inventors: Krahl Walter Louis
Original assignee: Arcturus Radio Tube Co
Current assignee: Arcturus Radio Tube Co
Priority date: 1927-08-05
Filing date: 1927-08-05
Publication date: 1932-08-02
Anticipated expiration: 1949-08-02

Description

2, 1932- w. L. KRAHL FULL WAVE RECTIFIER Filed Aug. 5, 1927 Z-Sheets-Sheet 1 INVENTOR MINE/e .4. kfi'Al-IL ATTORNEY Aug. 2, 1932. w, L, KRAHL 1,869,567

FULL WAVE RECTIFIER Filed Aug. 5. 1927 2 Sheets-Sheet 2 INVENTOR WALTER L. ARxmm ATTORNEY Patented Aug. 2, 1932 UNITED STATES PATENT OFFICE WALTER LOUIS KRA HL, OF-MONTCLAIR, NEW JERSEY, ASSIGNOR TO ABCTURUS R ADIO TUBE COMPANY, OF NEWARK, NEW JERSEY, .A CORPORATION OF DELAWARE FULL WAVE ancrrrmza Application filed August 5, 1927. Serial No. 210,809.

This invention relates to rectifiers and particularly those adapted to rectify both sides of an alternating current wave. 7

One of the objects of the invention is to provide a full wave rectifier which may be confined within a single glass envelope.

Another object of the invention is to pro-v vide a full wave rectifier in which a plurality of anode plates cooperate with a single cathode to rectify both sides of the alternating current wave.

Another object of the invention is to provide means to reduce the cree age effect hetween'the conductors of a recti er.

Another object of the invention is to provide a full wave rectifier tube in which the various parts are compact and the terminal contacts of which are all mounted in the base of the tube.

Other objects, and especially those related to economies of manufacture will be apparent as the description of the invention proceeds.

One'embodiment of the invention has been illustrated in the accompanying drawings, in which Fig. 1 is a perspective view partly in sec- 7 tion of a tube embodying my invention; and

Figs. 2 and 3' are diagrammatic views of circuits in which my improved tube may be i used.

The rectifier tube has been illustrated as comprising an envelope 10 sealed to a stem 11 in the usual manner and cemented in a base 12 by which the tube is adapted to be supported. A cathode 13 is supported from the stem 11 in the following manner A short conductor wire 14 is sealed into the upper end of the stem-and forms a support for the lower end of the cathode 13, While the upper end of the cathode is supported by a relatively longer conductor wire 15 which is also sealed in the upper end of the stem 11, and which is bent outwardly and upwardly, terminating at a point adjacent the top of the envelope 10. A connection 16 from the top of the cathode 13 is welded or otherwise attached to the upper end of the support 15.

The cathode is preferably formed in the shape of a hollow cylinder, and may be atment is attached at its lower end to a short conductor support 20, and at its upper end to a thin, flat spring 21 which is in turn welded to the upper end of the support 15 and extends transversely thereto. The filament 19 is preferably composed of carbon, first plated with copper, and then plated with nickel, which permits it to be readily welded to the support 20 at the bottom and the spring 21 at the top. The spring 21 tends to draw the filament 19 upwardly and thereby maintains the filament spaced from the cathode, compensating for changes in temperature when the tube is out into and out of service.

A pair of anode plates 22 are supported-adjacent the cathode 13, but spaced therefrom. These plates, which may be formed of nickel, molybdenum or the like are preferably semicylindrical in form, each being composed of two quarter cylindrical sections 23 and 23a with

fiat projections

24 and 25 riveted or otherwise attached together so that when placed on opposite sides of the'cathode 13, the plates are substantially parallel to the surface of the cathode. In order to support the plates 22, I have provided

wires

28 and 29 which enter tubes 25a, formed in the flat plate projections 24 and'25 and are welded thereto, and which are bent backwardly and downwardly and secured at their lower ends to a glass head 30. The lower ends of the plates 22 are supported by the lead wires 26 and 27 which are sealed into the stem and which extend into the lower ends of the tubes 25a formed in the

flat plate projections

24 and 25 and are welded therein.

In order to reduce to a minimum any tendenc for creepage from the conductors 26 I an 27 where'they are sealed in the stem 11, I have provided two

glass tubes

31 and 32 around the wires 26 and 27, res ectively, and melted into the upper part 0 the stem 11. This may very easily be done when the wires are sealed into the neck by placing the

tubes

31 and 32 around their respective wires before the upper end of the stem is pressed into position. The

glass tubes

31 and 32 extend upwardly a short distance and therefore greatly increase the surface distance on the glass from the wires 26 and 27 to the other conductors sealed in the stem 11.

The various connections to the parts of the rectifier are all made through the base 12 of the tube. To this end,

contact terminals

33, 34/35 and 36 are embedded in the base and extend downwardly therefrom in the usual manner. The

terminals

33 and 34 are connected respectively to the conductors 20 and 15 and therefore connect with the lower and upper ends of the filament 19, and the filament therefore may be energized by passing acurrent through the

terminals

33 and 34. The lower cathode support 14 is connected to the terminal 34, while the upper end of the cathode is connected by means of the strip 17 and the connector 16 to the upper end of the support 15 which is also connected to the terminal 34, thus connecting both the upper and lower end of the cathode to the single terminal 34. The plate supports 26 and 27 are connected respectively to the

terminals

35 and 36, as will be seen from Fig. 1.

In Figs. 2 and 3'of the drawings, two circuit diagrams havebeen shown, illustrating the manner in which the rectifying tube may be connected in a circuit. In Fig. 2, a transformer 37 is provided having a primary coil 38 adapted to be connected to a source of alternating current, and secondary coils 39 and 40. The secondary coil 40 has a limited number of turns, and is connected to the two

terminals

33 and 34, so that the filament 19 may be energized by alternating current at reduced voltage. The coil 39 may be connected to the plates 22 and 23 through the

terminals

35 and 36 respectively. A tap 41 is provided at the center of the secondary coil 39, and is connected to the terminal 34.

In the operation of the device when the transformer is energized, alternating current is induced in the coil 39, but owing to the fact that electron emission will only occur from the cathode 13 to the plates 22 and 23, current will flow in the leads between the plates 22 and 23, and the ends of the coil 39, in one direction only. In Fig. 2 the

loads

42 and 43 have been shown in the circuits of the plates 22 and 23 respectively, and also filters 44 and 45, where such filters are desirable. This type of circuit may be advantageously emplaved in a radio circuit for an eliminator or other devices requiring rectified current.

In Fig. 3 a similar circuit is shown with the exception that the load 46 is shown in the connection between the tap 41 on the secondary coil 39 and the terminal 34 of the tube. A filter 47 may also be used if desired. This arrangement may be used wherever a single circuit of rectified current is required.

The cylindrical cathode insures a steadier electron emission. This is because the electron emission is controlled by the heatof the cathode and the greater the mass of the cathode the less variation of heat there will be and hence this tube will provide a more even flow of current than ifan ordinary filament were used for the cathode.

It will be noted that I have provided a rectifying tube which will rectify both sides of the alternating current wave, and which is compact, easily manufactured, and the terminals of which are all mounted in the base of the tube. 2

In my application, Serial No. 140,245 for vacuum tubes, filed October 8, 1926, I have shown a vacuum tube adapted to be used for radio use, and which is adapted to take alternating current directly from the electric light circuit. This tube has a filament and cathode similar to the tube of the present invention and acylindrical plate adapted to fit around the cathode similar to the plates in the present invention. The manufacture of the rectifying tube may be very advantageously carried on in connection with the tubes described in the application above referred to, inasmuch as the only changes necessary are the elimination of the grid from that tube and the splitting of the cylindrical plate into two halves and the provision of a separate supporting means for one of the plates so formed.

While I have described and illustrated one form of the invention, many modifications and changes in the construction thereof may be resorted to without departing from the spirit of the invention, and I do not desire to limit myself, therefore, to the specific construction shown, but to interpret the invention broadly, limited only by the appended claims.

Having thus described my invention, what I desire to claim is 1. A rectifier tube comprising a stem; aconductor extending through said stem and supported thereby; a cylindrical cathode mounted upon said conductor; a pair of conductors adjacent said first conductor, extending through said stem and supported thereby; a semi-cylindrical anode supported on each of said conductors adjacent said cathode but spaced therefrom and from each other, each of said anodes comprising a. pair of plates having flanges and secured together III by means of said flanges; means comprising an insulating member for maintaining the opposite ends of said anodes in spaced relation; and an atmosphere of greatly reduced pressure surrounding said cathode and anodes.

2. A rectifier tube comprising astem; a conductor extending through said stem and supported thereby; a cylindrical cathode mounted upon said conductor; a pair of conductors adjacent said first conductor, extending through said stem and supported thereby; a semi-cylindrical anode supported on each of said conductors adjacent said cathode but spaced therefrom and from each other, each of said anodes comprising a pair of quarter-cylindrical plates each having a longitudinal flange at one side thereof, said plates being secured together by said flanges,

means comprising an insulating member for maintaining the opposite ends of said anodes in spa ed relation; and separate means to heat said cathode.

3. In a rectifier tube comprising a stem; a

conductor sealed in said stem; a cylindrical cathode, one end of which is attached to and suppo ted by said conductor; a second conductor sealed in said stem and attached to the other end of said cathode; an additional pair 39 of conductors sealed in said stem; a semicylindrical anode plate attached to each of said additional conductors, said plates comprising a pair of quarter-cylindrical plates each having a radial flange longitudinally extending on one side thereof, said plates being secured together by said flanges; an insulating member attached to one of said first mentioned conductors; a pair of supports connected to said insulating member and the 4 other end of said anode plates, said plates being spaced from each other and from said cathode and substantially concentric with the latter; and means for separately heating said cathode.

4. In a rectifier tube, a cylindrical cathode;

means to support said cathode; a pair of semi-cylindrical plates on opposite sides of said cathode and spaced therefrom-and from each other, but substantially concentric there- 60 with, said plates each comprising a pair of quarter-cylindrical plates having a longitudinal flanges on one side thereof extending in a direction radial to the center of curvature of the plate, said plates being held together portions of the flange of one plate extending through openings in the flange of the other plate and being bent over on the other side thereof; and a separate heater for said cathode.

6 In testimony whereof, I aflix my signature.

- WALTER L. KRAHL.