US2492343A

US2492343A - X-ray system

Info

Publication number: US2492343A
Application number: US599334A
Authority: US
Inventors: Charles T Zavales
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1945-06-14
Filing date: 1945-06-14
Publication date: 1949-12-27
Anticipated expiration: 1966-12-27

Description

Dec. 27, 1949 g. T. ZAVALES X-RAY SYSTEM Filed June 14, 1945 INVENTOR C. 7: Z/YV/YZES. WWW

ATTORNEY Patented Dec. 27, 1949 UNITED PATENT OF 'FI'CTE.

X-BAY SYSTEM Application June 14-, 1945, Serial No. 599,334

7; Claims. (01. 2501;0,0)

The present invention relates to- X-ray appara-tus and more particularly to an energizing system for an X-raytube wherein an indicator is employed to signal the operator during operationof the system that various parts thereof are properly functioning.

In high tension X-ray systems it is now quite customary to employ a full-wave bridge circuit rectifier arrangement so that the X-raytube isenergized by high potential; unidirectional electrical energy; However, should one of the rectifying valve tubes fail for any reason there has been no way in which this fact is ascertainable resulting in perhaps many faulty radiographs before discovery; with attendant wastage of film in addition to the remaking of the exposure.

It is accordingly the primary object of the present invention to eliminat the. above n ed isadvantages by the provision of an indicator t signal or indicate, to the operator whether or not the rectifying valves are; properly iunctioning.

Another object. of the resent invention is, the provision of an indicator included in the low volt.- age metering circuit which will give an accurate indication to an operator whether or not the high, voltage rectifying valve tubes are functioning properly.

Further objects of the present invention will become obvious tothose skilled in the art by ref-. erence to the accompanying, drawing wherein the single figure is a schematic illustration oi X- ray system constructed in accordance with the present invention.

Referring now to. the drawin in detail. the circuit arrangement in general is very similar to that shown and described in Patent No. 2,322,404, issued to Louis L. Weisglass on- June Z2, 19.43., and assigned to the same assign-ee as the present in! vention. The apparatus, comprises a high tension transformer 5. having its primary winding 6 con-.- nected to a source of A. C. current of the usual; commercial potential Ll, L2. The secondary winding i of this hi h ten ion. rans-mime! is. connected by a conductor 8 to, the cathode andanode of a pair of high voltage rectifying, valve tubes 9 and Ill, respectively, while the remaining.

end, of this secondary winding l is similarly con.-

nected y a conductor [2 to the cathode and anode of a further pair of high voltage 1ectify-. ing valve tubes l3v and I4, respectively. These rectifying valve tubes; are of the thermionic type and have their cathodes heated from the customary low voltage transformer which has not been shown tor simplicity.

An X-ray tube l5; has. its anode; cqnnccted by a conductor [6 to the, cathode oi the respec: tive valve tubes to and M while its; thermionic cathode is similarly connected by a conductor H: to the anode of the respective voltage hectifying valve tubes 9. and t3, thus completing a. full wave rectifying bridge circuit of the usual type. The thermionic cathode of the, X-ray tube, l5 receives heating energy from a. low voltage, transformer 18. the primary winding of which may; be connected to. the same commercial; source of supply Ll, L2 as. the primary winding 6; of the high voltage transformer 5.. Thesecondarv winding 1 is connected to ground G.- at its. midpoint.

and a condenser I9; is connected series; Willi-1' the secondary winding 1 to compensate, for the capacity effect in the latter windin In order to. measure; the trueuseful current supplied to. the. X-raytube- IS. a direct current meter 22 of the DArsonval type. is, connected to a bridge rectifying circuit. similar to. the X-ray tube, so that unidirectional current is supplied to the; meter 22. For this purpose one side of the meter 22 is connected to the cathode of a pair of low voltage. rectifier-s 23: and 24., which may be thecopper oxide type known as Rectox but prefie-rably are mercury filled rectifiers as mentioned in the above noted Patent- No. 2,322,4(14, while the other side of the meter 22. is connected to the anodes of a. similar pair of rectifiers. 25; and 26, and a condenser 21f is shunted across. the meter 22 as a protective. capacitor for the meter.

lihe anode and cathode of the respective rectifiers 23 and 25: are grounded as at. G while the anode and cathode of the respective rectifiers 2'4; and 26: are. connected by a conductor 2-3.- to. a com pensating winrhng ot the high voltage secondary winding 1. The system thus far described diiiers very little from that shown and claimed in the above mentioned patent and hence functions in the identical manner to record the true useful current flowing through the X-ray tube.

Inaccordance with the present invention, however, a discharge device such as a neon lamp 29- provided with electrodes at and c and sh-unted'by a resistance 30 for limiting the current passing through the lamp, is interposed in the conductor 28 and thus in series with the rectifying bridge arrangement for the meter 22-. During each half wave of the alternating current cycle when cur-- rent fiows through the secondary winding 1, it also flows simultaneously through the lamp 29, with its inherent A. G. sine- Wave, although flowing unidirectionally through the meter 22 due to the rectifying arrangement.

Accordingly, when current is flowing through the high voltage energizing circuit for the X-ray tube and simultaneously through the neon lamp 29 both electrodes at and c of the latter will glow. This will be better appreciated if it be assumed that at a given instant the end of the secondary winding 1 connected to the cathode of high voltage rectifying valve 9 is negative then such valve tube, as well as the valve tube M, will be conductive and high voltage electrical energy will flow through the X-ray tube and back (through rectifier M) to the other end of the secondary winding 1. At this same instant that rectifying valves 9 and M are conductive, current is flowing through the meter circuit in one direction and electrode a. of the neon lamp will glow since the latter is so connected that electrode a is momentarily positive when valves 9 and is are conductive.

During the next half wave of the alternating current cycle the polarity reverses so that high voltage rectifiers iii and I3 become conductive with reversal in the direction of current flow through secondary winding 3 as well as through the meter circuit so that electrode of the neon lamp 29 now glows. Consequently if one electrode of the neon lamp glows during one half cycle when current is flowing through high voltage rectifying Valves 9 and i i and the other electrode glows when current is flowing through rectifying valves 10 and i3, then the visual or indicating effect of the neon lamp to the operator is that all rectifying valves are properly functioning because both electrodes of the neon lamp would be glowing.

If, however, in the case assumed either of valves 9 or I4 becomes defective, then the electrode a ceases to glow indicating one or both have failed; and in a similar manner, should the electrode 0 of the neon lamp 29 cease to glow, this indicates that one or both of the rectifying valves III or l3 have become defective.

It will thus become obvious to those skilled in the art that an X-ray system is herein provided in which an indicator in the form of a neon glow lamp is utilized to give an indication to the operator whether or not the high voltage rectifying valves are properly functioning. Should one fail the apparatus is immediately de-energized b the operator thus avoiding the possibilit of making faulty radiographs with wastage of film.

Although one embodiment of the present invention has been shown and described, it is to be understood that still further modifications thereof may be made without departing from the spirit and scope of the appended claims.

I claim:

1. An X-ray system comprising an X-ray tube, a high potential source of alternating current electrical energy, rectifying means connected to said source and to said X-ray tube for converting the energy supplied to said X-ray tube into unidirectional current, and means connected to said high potential source and in series with said X- ray tube but subject to a slightl less current flow than said X-nay tube and operable during each half wave of the alternating current cycle to indicate to an operator the particular sine of the alternating current cycle normally passed by said rectifying means and to identify the particul-ar rectifying means upon failure thereof to pass current of a given sine wave.

2. An X-ray system comprising an X-ray tube,

a source of alternating current electrical energy,

including a transformer having a high potential secondary winding, rectifying valve tubes connected to the high potential secondary winding of said transformer and to said X-ray tube for converting the energy supplied by the secondary winding to said X-ray tube into unidirectional current during the entire alternating current cycle, and indicating means connected to a portion of said high potential secondary winding and in series with said X-ray tube and subject to a current flow of lesser magnitude than that supplied to said X-ray tube and operable during the entire alternating current cycle to indicate to an operator the particular sine of the alternating cur-rent cycle normally passed by said rectifying valve tubes and to identify the particular rectifying valve tubes upon failure thereof to pass current of a given sine wave.

3. An X-ray system comprising an X-ray tube, a source of alternating current electrical energy including a transformer having a high potential secondary winding, rectifying valve tubes connected to the high potential secondary winding of said transformer and to said X-ray tube for convertin the energy supplied by the secondary winding to said X-ray tube into unidirectional current during the entire alternating current cycle, and a glow lamp having electrodes therein connected in series with said high potential secondary winding of said transformer and said X- ray tube and operable during the entire alternating current cycle to indicate to an operator the particular sine of the alternating current cycle normally passed by said rectifying valve tubes and to identif the particular rectifying valve tubes upon failure thereof to pass current of a given sine wave.

4. An X-ray system comprising an X-ray tube, a source of alternating current electrical energy including a transformer having a high potential secondary winding, rectifying valve tubes connected to the high potential secondary winding of said transformer and to said X-nay tube for converting the energy supplied by the secondary winding to said X-ray tube into unidirectional current during the entire alternating current cycle, and a glow lamp having electrodes therein comiected in series with said high potential secondary winding and said X-ray tube and operable during the entire alternating current cycle to support a glow discharge at one or both of its electrodes to indicate to an operator the particlar sine of the alernating current cycle normally passed by said rectifying valve tubes and to identify the particular rectifying valve tubes upon failure thereof to pass current of a given sine wave.

5. An X-ray system comprising an Y-ray tube, a source of alternating current electrical energy including a transformer having a high potential secondary Winding, rectifying means connected to said secondary winding and to said X-ray tube for converting the energy supplied by said secondary winding to said X-ray tube into unidirectional current, a metering circuit including said X-ray tube and said high potential secondary winding which carries a capacity current due to the capacity of the high potential circuit and including a meter for measuring the current supplied to said X-ray tube, and means connected in series with said meter for indicating to an oper- .failure thereof to pass current of a given sine wave.

6. An X-ray system comprising an X-ray tube, a source of alternating current electrical energy including a transformer having a, high potential secondary winding, rectifying means connected to said secondary winding and to said X-nay tube for converting the energy supplied by said secondary Winding to said X-ray tube into unidirectional current, I2, metering circuit including said X-ray tube and said high potential secondary winding which carries a capacity current due to the capacity of the high potential circuit and including a meter for measuring the current supplied to said X-ray tube, and a glow lamp provided with electrodes connected in series with said meter and operable by the occurrence of a glow discharge at one or both of its electrodes to indicate to an operator during the entire alternating current cycle the particular sine of the alternating current cycle normally passed by said rectifying means and to identify the particular rectifying means upon failure thereof to pass current of a given sine wave.

7. An X-ray system comprising an X-ray tube, a source of alternating current electrical energy including a transformer having a high potential secondary winding, rectifying means connected to said secondary winding and to said X-nay tube for converting the energy supplied by said se'c ondary winding to said X-ray tube into unidirectional current, 'a metering circuit including said X-ray tube and said high potential secondary winding which carries a capacity current due to the capacity of the high potential circuit and including a series connected meter for measuring the current supplied to said X-nay tube, a glow lamp provided with electrodes connected in series with said meter and operable by the occurrence of a glow discharge at one or both of its electrodes to indicate to an operator during the entire alternating current cycle the particular sine of the alternating current cycle normally passed by said rectifying means and to identify the particular rectifyin means upon failure thereof to pass current of a given sine wave, and an impedance connected in shunt to said glow lamp for limiting current flow in the latter.

CHARLES T. ZAVALES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,703,147 Holden Feb. 26, 1929 2,128,080 Dawson Aug. 23, 1938 2,212,025 Kent Aug. 20, 1940 2,232,284 TiSZa Feb. 18, 1941 2,244,137 Bischofi et a1 June 3, 1941 2,322,404 Weisglass June 22, 1943 2,411,848 Camras Dec. 3, 1946