Pulse transformer with magnetron well

April 17, 1951 w. h. bostick

PULSE TRANSFORMER WITH MAGNETRON WELL

2,549,366

Filed Aug. 2, 1945

Sheets-Sheet 1

<img file="US2549366A_D0001.tif" />

<img file="US2549366A_D0002.tif" />

INVENTOR

WINSTON H. BOSTICK

ATTORNEY

<td> April 17, 1951</td><td> w. h. bostick 2,549,366 PULSE TRANSFORMER WITH MAGNETRON WELL</td>

<td> Filed Aug. 2, 1945</td><td> 2 Sheets-Sheet 2</td>

FIG. 3

<img file="US2549366A_D0003.tif" />

<img file="US2549366A_D0004.tif" />

INVENTOR

WINSTON H. BOSTICK ^BY

ATTORNEY

Patented Apr. 17, 1951

2,549,366

UNITED STATES PATENT OFFICE

2,549,366

PULSE TRANSFORMER WITH MAGNETRON WELL

Winston H. Bostick, West Medford, Mass., assignor, by mesne assignments, to the United States of America as represented by the Secretary or the Navy Application August 2,

Claims.

This invention relates in general to the combination in a single structure of a transformer and a socket for an electron tube, and in particular to such a combination of pulse transformer and a socket for a magnetron type electron tube together with a. mechanical support for such a tube.

In systems for the transmission of pulses of high frequency radio energy produced by an electron tube oscillator, it is usual to apply modulation voltage simultaneously to both filament leads of the electron tube oscillator through a high voltage pulse transformer. Magnetron type electron tubes are commonly used, the anode of the electron tube being kept at ground potential. The electron tube oscillates when a negative voltage pulse is applied to the cathode. In such a system the cathode heater leads thus also carry highly negative voltage pulses and require substantial insulation as well as careful shielding. So also, the socket holding the electron tube must be carefully insulated.

It is a specific object of my invention to provide a single structure for holding.a pulse transformer and a socket for a magnetron type electron tube.

It is a further object of my invention to eliminate long cathode leads and to provide efficient shielding for the short leads remaining,.

It is a still further object of my invention to provide a mechanical support for a magnetron type electron tube oscillator, while at the same time providing in the same structure a socket and transformer therefor.

Other objects and features. of my invention will ; become apparent upon a careful consideration of the following detailed description when taken together with the accompanying¹ drawings, the figures of which illustrate typical embodiments Of the invention.

Fig. 1 is an electrical schematic diagram of a pulse transformer and magnetron oscillator tube showing means for modulating that tube through its cathode;

Fig. 2 shows a combined transformer,, socket , and support of my invention with a magnetron type oscillator tube being inserted into the socket; and

Fig. 3 shows in cross section another transformer and socket combination of my invention j showing the structure, in electrical scheme, of a transformer in the outer housing thereof.

Referring now to. Fig. 1, a transformer ! having a primary winding 2, and two secondary windings 3. and 4, has its. primary winding 2. connected i

1945, Serial No. 608,595 (Cl. 250—16) at one end to ground and at the other end to a coaxial high frequency type cable 5 which is fed by signals from a pulse generator, not shown in Fig. 1. Each secondary winding 3 and 4 is con5 nected at one end to a first terminal connector S or 7 respectively and at the other end to a second terminal connector 8 or 9 respectively. A filament transformer 10 has its secondary i i connected to the second pair 8 and 9 of the afore10 mentioned connectors. One terminal 9 is connected to ground, usually through a by-pass capacitor 18. A second by-pass capacitor 19 is connected between the two terminals 8 and 9. The first pair δ and 7 of the aforementioned con15 nectors are brought to a pair of filament leads and ί 3 respectively. An electron tube ! 4 which may be of the magnetron type has its cathode heater 15' connected to the aforementioned filament leads 12 and 13, and its cathode 15 con20 nected directly to one of said leads !3. The electron tube 14 has its anode 17 grounded, and is arranged to oscillate at high frequency when the voltage on the cathode (5 is dropped below a predetermined negative potential. When oscil25 lations take place, they are taken from the electron tube 14 by means of a high frequency pickup 16.

The system illustrated in Fig. 1 operates as follows. When a voltage pulse of the proper 30 polarity is applied to the transformer I through the cable 5, a negative voltage pulse appears at each of the first pair of the aforementioned connectors 6 and 7 and is applied through the leads 12 and 13 to the cathode 15 of the electron tube

14. Simultaneously filament heating voltage from the transformer 19 is applied to the same filament or cathode IS through the two secondary windings 3 and 4 of the transformer I. It is the electrical organization or circuit of Fig. 1 that I have placed into a common structure with a socket and support for the electron tube 14, as illustrated in Figs. 2 and 3.

In Fig. 2 a transformer, socket and mounting combination 29 of my invention is shown together with the magnetron type electron tube 14. The magnetron 14 is about to be inserted into the socket 22 of the structure 20. The transformer 20 has an outer metallic liquidtight housing 23 and a cylindrical non-conductive liquidtight socket housing 24, preferably made of porcelain, rubber or other suitable insulating material. The two housings 23 and 24 are liquidtight at their common junction 21. A flat annulus 25 is provided for holding the base 26 of the magnetron type oscillator tube 14 in firm

2,549,366 supported relationship by means of bolts, not shown, and holes 27 and 28, the latter of which are threaded. The flat annulus 25 is electrically and mechanically a part of the housing 23, which housing 23 is normally grounded in the radio 5 system in which it may be installed. The magnetron tube 14 has for its anode 29 the outer shell or casing thereof. The cylindrical portion 29 of the magnetron tube (4 is the anode. Cooling fins 30 are arranged about this anode 29. The anode 29 is electrically and mechanically connected to the base mounting plate 26. Thus, when the mounting plate 26 and the flat annulus are brought together in fixed mechanical relation, the anode 29 is grounded through the case or housing 23 of the transformer socket combination 20. Cathode heater voltage is brought to the magnetron 14 by means of two leads 31 and 32 coming out of the bottom of the base plate and insulated therefrom. The ends of the two leads 31 and 32 may have spring-like fingers formed by cutting slots 33 in those ends. In the socket 22 of the transformer 20, there are two plugs or connectors 34 and 35, which may be of many forms, such as for example banana plugs, arranged to cooperate with the ends of the two aforementioned leads 31 and 32 respectively when the magnetron tube 14 is inserted therein. The plugs 34 and 35 will preferably make firm electrical contact with the respective ends of the 30 leads 31 and 32. The two plugs 34 and 35 are mounted upon a flat disc-shaped plate 36 of nonconductive material such as mica, for example, which may be resiliently mounted in the socket in a manner not shown in Fig. 2, but shown 35 in Fig. 3. Two external binding posts 37 and 38 are connected to the two plugs 34 and 35 respectively through transformer secondary windings not shown in Fig. 2, but similar to the secondary windings 3 and 4 of Fig. 1. The binding posts 37 and 38 are used to bring cathode heater power to the cathode of the magnetron 14, and correspond to the second pair of terminals 8 and 9 of Fig. 1. The two plugs 34 and 35 correspond to the first pair of terminals 6 and 7 of Fig. 1. Voltage pulses are brought into the combined transformer and socket 20 through a coaxial connector 39 which corresponds to the coaxial high frequency line 5 of Fig. 1. The apparatus illustrated in Fig. 2 will operate in a manner identical to the apparatus illustrated in Fig. 1. High frequency oscillatory energy is taken from the electron tube 14 through the terminal 40' of the output coupling mechanism of that tube.

In Fig. 3 is illustrated partly in cross-section a s: transformer and socket combination of my invention, showing therein a schematic diagram of a pulse transformer and structurally a socket for an electron tube and a housing for the said transformer and socket. An outer housing 40 encloses the entire structure with the exception of external lugs 41 and 42 for bringing filament voltage for a magnetron tube into the structure, and with the further exception of a coaxial connector 43 for bringing modulation voltage pulses into the structure. A transformer, similar to the transformer I of Fig. 1, having a primary winding 44 and two secondary windings 45 and 46 is in the upper portion of the housing 40. A cylindrically shaped socket 47, made of non-conducting material which may be porcelain or rubber as aforementioned in connection with the apparatus of Fig. 2, is inserted in the lower portion of the outer housing 40. Two plugs 48 and 49, similar to and for the same purpose as the two corre4 sponding plugs 34 and 35 of the apparatus of Fig.

2, are supported upon a resiliently mounted nonconductive disc-shaped plate 50. The discshaped plate 50 serves the same purpose as the corresponding disc-shaped plate 36 of the apparatus of Fig. 2, and is resiliently mounted on spring members 51 and 52 which are fastened to the socket 47 by means of detents 70 therein. The spring members 51 and 52 are fastened to the 10 disc-shaped member 50 by means of bolts 53 and respectively. Lugs 55 and 56 are bolted to the plugs 48 and 49 respectively and serve as connectors for wires 59 and 60 respectively for bringing electric current to those plugs. Liquid-tight seals, 15 which may comprise insulating liquid-tight bushings 57 and 58 are provided to pass said wires 59 and 60 through the wall of the socket 47. Alternatively, the wires 59 and 60 may be simply sealed into the wall of the socket 47. The wires 59 and 20 60 are further connected each to one end of a secondary winding 45 and 46, respectively, of the transformer mounted in the upper part of the housing 40. The other end of each of these secondary windings 45 and 46 is further con25 nected to another wire 61 and 62 respectively, and these respective wires 61 and 62 are each further brought to and connected to the aforementioned external lugs 41 and 42 respectively. The lugs 4i and 42 are mounted upon the housing 40 by means of insulating bushings 63 and 64, respectively, and current is passed through the housing 40 by means of conductors 65 and 66 respectively carried by these insulating bushings 63 and 64. The respective wires 6 ( and 62 from the secondary windings 45 and 46 are electrically connected to these conductors 65 and 66 respectively. The primary winding 44 of the transformer is at one end connected to the inner conductor 67 of the coaxial connector 43, and at the other end 68 to the hous40 ing 40 in firm electrical contact therewith, thus forming a ground connection for one end of the primary winding 44. A non-conductive, liquidtight support 69 is furnished for the inner conductor 67 of the coaxial connector 43. Liquid45 tight fittings 69, 57, and 58 having been provided where appropriate, the outer housing 40 of the structure of apparatus, Fig. 3 may be filled with oil 7i if desired. Thus the transformer may be surrounded with oil if desired and have its high 50 voltage characteristics improved.

It should be apparent that the transformer in the apparatus of Fig. 3 is substantially identical to the transformer I of the apparatus of Fig. 1. Likewise the transformer-socket combination 20 of Fig. 2 and the apparatus of Fig. 3 are two different views of substantially the same apparatus.

Although I have shown and described only certain specific embodiments of my invention, I am fully aware of the many modifications possible 3° thereof. For example, the invention may, if desired, be used with electron tubes other than the magnetron type electron tube which has been illustrated. Therefore this invention is not to be limited except insofar as is necessitated by the ⁶⁵ prior art and the spirit of the appended claims.