US1871248A - X-ray system - Google Patents

Description

Aug. 9, 1932.

H. F.WA1TE X-RAY SYSTEM Fil'ed Deo. 1, 1951 mmm@ ' Patented Aug. 9, 1932- PATENT oFF-ICE HARRY F. WAITE, F NEW YORK, N. Y.

X-RAY SYSTEM Application led December l, 1931. -Serial No. 578,256.

The object of my invention is to provide a system in which a sudden disruption of the X-ray tube will not do damage to other parts of the system; and a further object is to provide a system wherein there will be a proper electron How through the X-ray tube regardless of the volume of current passing through the tube. These and other objects are accomplished by my invention, one embodiment of which is hereinafter more particularly set forth.

For a more particular description of my invention, reference is-to be had to the accompanying drawing, forming a part hereof, in

which The ligure shows a diagrammatic view of my invention.

The source of power is an alternating current which, for convenience,.is indicated di- `0 agrammatically at 1, as an alternating generator of a single phase type, although my invention is equally applicable to any source of alternating current or pulsating current suitable for X-ray Work. From this generator 15 run the usual leads 2 and 3 which are connected as will now be described.

l The principal circuit is through a regulator 4, wire 5, primary 6 of a high tension transformer 7, wire 8, primary 9 of a regu- 30 lating transformer 10 and thence to the wire 2.

Another circuit is from the wire 2 through the wire 11 to a regulator 12, thence through a wire 13 to the primary 14 of a step-down filament transformer 15, this transformer being for a hotcathode X-ray tube, as will appearbelow. From the primary .14 another wire 16 runs to the wire 3.

A third circuit is by the wire 17 connected to the wire 3, to the secondary 18 of the regulating transformer 10, and thence through a wire 19 to the primary 20 of a ilament transformer 21 for a hot cathode valve tube, which will be described below, and thence through a wire 22 to the wire 2.

The induced circuits will now be considered. Beginning with the secondary 23 of the high voltage transformer 7 one wire 24 runs from this secondary to one of the cathode 50 wires 25 of the hot cathode X-ray tube 26.

This tube 26 has a second cathode wire 27 and these wires and 27 run to the secondary 28 of the filament transformer 15 and furnish the cathode heating current in the conventional manner. The tube 26 'has an 55 anode which is connected to a wire .29, which `runs to the cathode of a hot cathode valve tube 30 in the conventional manner, and this tube 30 has two cathode wires 31 and 34. The wire 31 runs from the wire 29 to the sec- 69 ondary 35 of the transformer 21 and the wire 34 runs from this secondary to the hot cathode of the valve tube 30. The anode is con-- nected by the wire 32 to the secondary 23 of the transformer 7.

From the foregoing, it is apparent that the regulating transformer has its primary in circuit withy the primary of the high voltage transformer, and its secondary in circuit with the primaryof the filament transformer for the hotcathode valve tube. The regulating transformer is carefully wound so as not to interfere with the normal operation of the hot cathode X-ray tube, but if a heavy current be passed through thisX-ray tube for the purposes of making an X-ray plate or for other purposes, greater power is drawn from the transformer 7- and greater power isdelivered at the 'primary of this transformer and the corresponding increase of power iS delivered to the primary 9 of the regulating'k transformer 10 with the result that increased power is given to the filament transformer 21, which in turn gives a brighter glow at the -cathode of the valve tube 30 with the result 35I that there is an increased electron discharge with the result thatincreased power is used at the X-ray tube 26 during the fraction of a second or other time that the tube is functioning. As soon as the X-ray tube has functioned in the desired'manner, only a normal current is passed through the hot cathode of the valve tube, which automatically adjusts itself in the manner above described, both for increase and decrease accordingl to the abnormal demands on the tube 26. As these abnormal demands are generally of very short duration, as a small fraction of a second,- for the taking of an X-ray plate, it is obvious that the life of the valve tube 30 is 100 greatly prolonged because its cathode is not overheated more than is absolutely essential for the functioning of the apparatus. If hand regulation were resorted to, for the urpose of governing the glow of this catho e in the tube 30, it would glow very much lon er than is essential under the conditions of e system of this invention, and so the life of the tube would be corre ondingly shortened.

At times the X-ray tu es 26 will short circuit and cease to function. When'this occurs a corresponding increase of current tends to surge through the secondary 23 and there is a correspon ing increase of power in the 15 primary 6. At such a time there is a corresponding increase of power in the primary 9 Y of the transformer 10 and an instant increase in the filament current of the hot cathode valve tube so that thel electron emission is 20 suiiicient to carry the increased high tension current without increase of voltage across valve tube, thus preventing the target in the valve tube from becoming heated and'thus giving ofi' a gas which interferes with the g5 proper function of valve tubes.

While I have shown and described one embodiment of my invention, it is obvious'that it is not restricted thereto, but that it is broad enough to cover all structures that come 30- within the scope of the annexed claim.

Having thus described my invention, what I claim is:

In a system of the class described, a hot cathode X-ray tube, a hot cathodevalve tube, a5 a, high voltage transformer, and connections to both tubes, means for furnishing the hot cathode X-ray tube with a suitable heating current, a transformer and means for connecting the same" to the hot cathode of the o valve tube, means for connecting the hot cathode valve tube with the hot cathode X- ray tube, and a regulating 'transformer having its primary in series with the primary of the high voltage transformer, and .its secondary in series with the primary of the `lilamnt transformer of the hot cathode valve tu e.

In testimony whereof, I have hereunto set my hand this 24 day of November, 19,31. 50 HARRY F. WAITE.

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