Starting voltage suppressor circuitry for an x-ray generator

Claim 2

In a multiphase X-ray generator, the combination comprising: an X-ray tube; transformer-rectifier means coupled to said X-ray tube, being responsive to the magnitude of a multiphase alternating current input voltage for providing a direct current voltage to said Xray tube; three-phase control autotransformer means coupled between said multiphase input voltage and said transformer-rectifier means for controlling the magnitude of the multiphase input voltage applied to said transformer-rectifier means for a desired exposure; auxiliary autotransformer means connected across one phase of said control autotransformer means for reducing the magnitude of the voltage input for an initial phase upon start of an exposure; and auxiliary switching means connecting said auxiliary autotransformer means to said transformer-rectifier means for applying at the start of an exposure a single-phase voltage thereto a reduced value compared to the magnitude of subsequent phase-to-phase voltages applied thereto whereby overshoot of the voltage to said X-ray tube is eliminated or held to a negligible value.

Claim 3

In a multiphase X-ray generator, the combination comprising: an X-ray tube; transformer-rectifier means coupled to said X-ray tube, being responsive to the magnitude of a multiphase alternating current input voltage for providing a direct current voltage to said X-ray tube. three-phase control autotransformer means including a tap switch connected to each phase and ganged together, coupled between said multiphase input voltage and said transformer-rectifier means, the setting of said tap switches controlling the magnitude of the phase-to-phase alternating current voltage applied thereto for a desired X-ray exposure; and another tap switch connected to one phase of said control autotransformer, coupled to said transformer-rectifier means providing a fixed reduced voltage thereto compared to the voltage setting of said tap switches for an initial phase upon start of an exposure whereby overshoot of the voltage to said X-ray tube is eliminated or held to a negligible value.

Claim 4

In a multiphase X-ray generator, the combination comprising: an X-ray tube; transformer-rectifier means coupled to said X-ray tube, being responsive to the magnitude of a multiphase alternating current input voltage for providing a direct current voltage to said X-ray tube. three-phase control autotransformer means including a tap switch connected to each phase and ganged together, coupled between said multiphase input voltage and said transformer-rectifier means, the setting of said tap switches controlling the magnitude of the phase-to-phase alternating current voltage applied thereto for a desired X-ray exposure; and another tap switch connected to one phase of said control autotransformer, coupled to said transformer-rectifier means providing a fixed reduced voltage thereto compared to the voltage setting of said tap switches for an initial phase upon start of an exposure whereby overshoot of the voltage to said X-ray tube is eliminated or held to a negligible value.

Claim 5

In a multiphase X-ray generator, the combination, comprising: an X-ray tube; transformer-rectifier means coupled to said X-ray tube, being responsive to the magnitude of a multiphase alternating current input vOltage for providing a direct current voltage to said X-ray tube; control autotransformer means coupled between said multiphase alternating current input voltage and said transformer-rectifier means for controlling the magnitude of the voltage applied to said transformer-rectifier means; and bucking transformer means including a first and a second winding, said first winding being connected to said control autotransformer means and said second winding being connected to said transformer-rectifier means so as to buck the voltage of the initial phase of said input voltage from said control autotransformer means upon start of an exposure whereby the input voltage applied to said transformer-rectifier means is reduced in magnitude compared to the magnitude of subsequent phases whereby overshoot of the direct current voltage to said X-ray tube is eliminated or held to a negligible value.

Claim 6

In a multiphase X-ray generator, the combination, comprising: an X-ray tube; transformer-rectifier means coupled to said X-ray tube, being responsive to the magnitude of a multiphase alternating current input vOltage for providing a direct current voltage to said X-ray tube; control autotransformer means coupled between said multiphase alternating current input voltage and said transformer-rectifier means for controlling the magnitude of the voltage applied to said transformer-rectifier means; and bucking transformer means including a first and a second winding, said first winding being connected to said control autotransformer means and said second winding being connected to said transformer-rectifier means so as to buck the voltage of the initial phase of said input voltage from said control autotransformer means upon start of an exposure whereby the input voltage applied to said transformer-rectifier means is reduced in magnitude compared to the magnitude of subsequent phases whereby overshoot of the direct current voltage to said X-ray tube is eliminated or held to a negligible value.

Claim 7

In a multiphase X-ray generator, the combination comprising: an X-ray tube; transformer-rectifier means coupled to said X-ray tube, being responsive to the magnitude of a multiphase AC input voltage applied thereto for providing a DC voltage to said X-ray tube; three-phase control autotransformer means coupled between said multiphase AC input voltage and said transformer-rectifier means for controlling the magnitude of the multiphase voltage input applied thereto for a desired exposure; switching means interconnected between said autotransformer means and said transformer-rectifier means for selectively connecting each phase of said AC input voltage to said transformer-rectifier means; means coupled to one phase of said autotransformer means for reducing the magnitude of the voltage for an initial phase of said AC input voltage; timing and gating means coupled to said switching means, gating said switching means to connect the phases of said AC input voltage to said transformer-rectifier means in a controlled sequence in the same way at the start of each exposure; and said switching means further including an auxiliary switch connecting said means for reducing the magnitude of the voltage for the initial phase to said transformer-rectifier means, said timing and gating means additionally being coupled to and enabling said auxiliary switch only during the period that said initial phase of said AC input voltage is applied at the start of any exposure whereby overshoot of the voltage to said X-ray tube is substantially eliminated or held to a negligible value.

Claim 8

In a multiphase X-ray generator, the combination comprising: an X-ray tube; transformer-rectifier means coupled to said X-ray tube, being responsive to the magnitude of a multiphase AC input voltage applied thereto for providing a DC voltage to said X-ray tube; three-phase control autotransformer means coupled between said multiphase AC input voltage and said transformer-rectifier means for controlling the magnitude of the multiphase voltage input applied thereto for a desired exposure; switching means interconnected between said autotransformer means and said transformer-rectifier means for selectively connecting each phase of said AC input voltage to said transformer-rectifier means; means coupled to one phase of said autotransformer means for reducing the magnitude of the voltage for an initial phase of said AC input voltage; timing and gating means coupled to said switching means, gating said switching means to connect the phases of said AC input voltage to said transformer-rectifier means in a controlled sequence in the same way at the start of each exposure; and said switching means further including an auxiliary switch connecting said means for reducing the magnitude of the voltage for the initial phase to said transformer-rectifier means, said timing and gating means additionally being coupled to and enabling said auxiliary switch only during the period that said initial phase of said AC input voltage is applied at the start of any exposure whereby overshoot of the voltage to said X-ray tube is substantially eliminated or held to a negligible value.