US4039811A — Method of operating and power supply for x-ray tu…

Claim 1

Independent Claim 75 words

Method of operating an X-ray tube of the kind that is energized from a conventional alternating current power source through a load responsive high voltage transformer comprising the steps of: varying the plate current in response to changes in the voltage of the source, thereby the changing the electrical load of the transformer to a degree that the output voltage of said transformer remains substantially constant independent of changes in the voltage across its input.

Claim 2

Dependent Claim 75 words

Method of operating an X-ray tube of the kind that is energized from a conventional alternating current power source through a load responsive high voltage transformer comprising the steps of: varying the plate current in response to changes in the voltage of the source, thereby the changing the electrical load of the transformer to a degree that the output voltage of said transformer remains substantially constant independent of changes in the voltage across its input.

Claim 3

Dependent Claim 18 words

Method according to claim 1 wherein the plate current is varied by varying the temperature of the cathode.

Claim 4

Dependent Claim 32 words

Method according to claim 1 wherein the X-ray tube is of the Coolidge type, and the plate current is varied by varying the filament current passed through the cathode to heat it.

Claim 5

Dependent Claim 42 words

Method according to claim 3 wherein the changes in the current passed through the cathode to heat it, taken as a fraction of the current, are limited to about 10% to 50% of the fractional changes of the voltage of the source.

Claim 6

Dependent Claim 39 words

Method according to claim 1, wherein the X-ray tube is of the kind having an electrode capable of functioning as a control grid, and the plate current is varied by varying the voltage between said electrode and the cathode.

Claim 7

Dependent Claim 28 words

Method according to claim 5 including the steps of turning the X-ray emission of the tube ON and OFF by varying the voltage between said electrode and cathode.

Claim 8

Dependent Claim 101 words

Apparatus for connection between an X-ray tube and a source of alternating current, the voltage of which may vary significantly from a nominal value, for providing and regulating the high voltage for the tube comprising: a. a loosely coupled load responsive high voltage transformer having a secondary winding to be connected across the plate and the cathode of the tube for supplying the plate current, b. means for varying the plate current of the tube in response to changes in the voltage of the source of current loading said transformer, so that the output voltage of said transformer remains substantially constant.

Claim 9

Dependent Claim 101 words

Apparatus for connection between an X-ray tube and a source of alternating current, the voltage of which may vary significantly from a nominal value, for providing and regulating the high voltage for the tube comprising: a. a loosely coupled load responsive high voltage transformer having a secondary winding to be connected across the plate and the cathode of the tube for supplying the plate current, b. means for varying the plate current of the tube in response to changes in the voltage of the source of current loading said transformer, so that the output voltage of said transformer remains substantially constant.

Claim 10

Dependent Claim 34 words

Apparatus according to claim 7 wherein said means for varying the plate current comprises means for varying the temperature of the cathode of the tube in fractional response to variation in the source voltage.

Claim 11

Dependent Claim 58 words

Apparatus according to claim 8 wherein the cathode of the tube is a filament and heated by electric current passed through it, and said varying means includes a partial voltage regulator connected between the source and the cathode for reducing the voltage variation that appear across the cathode relative to the variation that would appear there without regulation.

Claim 12

Dependent Claim 53 words

Apparatus according to claim 7 including a control grid within the X-ray tube between the cathode and anode thereof, and wherein said varying means comprises means for varying the voltage between the control grid and the cathode in direct proportion and in response to changes of the voltage of the source of current.

Claim 13

Dependent Claim 124 words

In combination with an X-ray tube having a plate and a cathode, a power supply for energization by line voltage and for providing a stabilized high voltage to said tube and comprising: a high voltage transformer having a primary coil and a secondary coil and characterized by having an output/input voltage ratio inversely dependent upon the load of said transformer; said primary coil energized by said line voltage; said secondary coil connected to said anode and cathode for applying high voltage thereto; current control means for controlling the current flowing between said plate and cathode in fractional response to variations in the line voltage thereby affecting the load on said transformer so that the high voltage between said anode and cathode is substantially constant.

Claim 14

Dependent Claim 124 words

In combination with an X-ray tube having a plate and a cathode, a power supply for energization by line voltage and for providing a stabilized high voltage to said tube and comprising: a high voltage transformer having a primary coil and a secondary coil and characterized by having an output/input voltage ratio inversely dependent upon the load of said transformer; said primary coil energized by said line voltage; said secondary coil connected to said anode and cathode for applying high voltage thereto; current control means for controlling the current flowing between said plate and cathode in fractional response to variations in the line voltage thereby affecting the load on said transformer so that the high voltage between said anode and cathode is substantially constant.

Claim 15

Dependent Claim 91 words

A power supply as defined in claim 11 wherein said cathode is a filament heated in response to an applied low voltage and said current control means is a voltage regulator interposed between said line voltage and said filament for partially regulating said low voltage to a degree that said filament emits current to said plate in response to the line voltage thereby varying the load on said high voltage transformer thereby changing the output/input voltage ratio so that the high voltage between said filament and said plate is substantially constant.

Claim 16

Dependent Claim 43 words

The power supply of claim 11 wherein said tube includes a control grid and said current control means is a bias generator interposed between said grid and said supply voltage for applying a bias voltage to said grid in response to line voltage.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1980-08-01	1981-01-31	1981-08-02	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1984-08-01	1985-01-31	1985-08-02	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1988-08-01	1989-01-31	1989-08-02	$7700.00	Window Closed / Lapsed

Method of operating and power supply for x-ray tubes

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