High voltage power supply for an X-ray tube
First Claim
1. A high voltage power supply for biasing an X-ray tube comprising:
- a first source of a reference voltage level that represents a desired bias voltage magnitude for the X-ray tube;
an inverter that produces an alternating voltage from a DC input voltage in response to control signals;
a voltage multiplier connected to said inverter to increase the alternating voltage thereby producing an output voltage of the power supply;
a voltage sensor for sensing the output voltage and producing a sensor signal indicating a magnitude of the output voltage;
a circuit coupled to said first source and said voltage sensor, and determining a difference between the sensor signal and the voltage level reference signal;
an integrator connected to said circuit to integrate the difference between the output voltage and the voltage level reference signal to produce an integrated signal;
a second source of a duty cycle reference signal;
a summation device coupled to said integrator, said second source and said voltage sensor for combining the integrated signal, the duty cycle reference signal and the sensor signal to produce a DUTY CYCLE COMMAND signal; and
an inverter driver coupled to said integrator and said summation device for generating control signals for said inverter wherein the control signals have frequencies defined by the integrator signal and have duty cycles defined by the DUTY CYCLE COMMAND signal.
1 Assignment
0 Petitions
Accused Products
Abstract
A supply for a high bias voltage in an X-ray imaging system has an inverter and a voltage multiplier that produce an alternating output voltage in response to control signals. A voltage sensor produces a signal indicating a magnitude of the output voltage. A circuit determines a difference between the sensor signal and a reference signal that specifies a desired magnitude for the output voltage and that difference is integrated to produce an error signal. The error signal preferably is summed with a precondition signal that is an approximation of a nominal value for the signal sum and the summation producing a resultant signal. Another summation device arithmetically combines the resultant signal and the sensor signal with a signal corresponding to a one-hundred percent duty cycle of the inverter operation in order to produce a duty cycle command. An inverter driver generates the inverter control signals that have frequencies defined by the resultant signal and have duty cycles defined by the duty cycle command. A unique state machine is described which generates those control signals.
-
Citations
15 Claims
-
1. A high voltage power supply for biasing an X-ray tube comprising:
-
a first source of a reference voltage level that represents a desired bias voltage magnitude for the X-ray tube; an inverter that produces an alternating voltage from a DC input voltage in response to control signals; a voltage multiplier connected to said inverter to increase the alternating voltage thereby producing an output voltage of the power supply; a voltage sensor for sensing the output voltage and producing a sensor signal indicating a magnitude of the output voltage; a circuit coupled to said first source and said voltage sensor, and determining a difference between the sensor signal and the voltage level reference signal; an integrator connected to said circuit to integrate the difference between the output voltage and the voltage level reference signal to produce an integrated signal; a second source of a duty cycle reference signal; a summation device coupled to said integrator, said second source and said voltage sensor for combining the integrated signal, the duty cycle reference signal and the sensor signal to produce a DUTY CYCLE COMMAND signal; and an inverter driver coupled to said integrator and said summation device for generating control signals for said inverter wherein the control signals have frequencies defined by the integrator signal and have duty cycles defined by the DUTY CYCLE COMMAND signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A high voltage power supply for biasing an anode and a cathode of an X-ray tube
a first source of a reference voltage level that represents a desired bias voltage magnitude for the X-ray tube; -
an anode inverter that produces an alternating anode bias voltage from a DC input voltage in response to anode inverter control signals; an anode voltage multiplier connected to said anode inverter to increase the alternating voltage thereby producing an anode output voltage; an anode voltage sensor for sensing the anode output voltage and producing a first sensor signal indicating a magnitude of the anode output voltage; an cathode inverter that produces an alternating cathode bias voltage from a DC input voltage in response to cathode inverter control signals; an cathode voltage multiplier connected to said cathode inverter to increase the alternating voltage thereby producing an cathode output voltage; an cathode voltage sensor for sensing the cathode output voltage and producing a second sensor signal indicating a magnitude of the cathode output voltage; a circuit coupled to said first source and to said anode and cathode voltage sensors, and producing a difference signal indicating a degree of difference between combination of the first and second sensor signals and the voltage level reference signal; an integrator connected to said circuit to integrate the difference signal to produce an integrated signal; a second source of a duty cycle reference signal; a first summation device coupled to said integrator, said second source and said anode and cathode voltage sensors for combining the integrated signal, the duty cycle reference signal and the first and second sensor signals to produce an ANODE DUTY CYCLE COMMAND signal; a second summation device coupled to said integrator, said second source and said anode and cathode voltage sensors for combining the integrated signal, the duty cycle reference signal and the first and second sensor signals to produce an CATHODE DUTY CYCLE COMMAND signal; and an inverter driver coupled to said integrator and said first and second summation devices for generating the cathode inverter control signals having frequencies defined by the integrator signal and duty cycles defined by the CATHODE DUTY CYCLE COMMAND signal, and generating the anode inverter control signals having frequencies defined by the integrator signal and duty cycles defined by the ANODE DUTY CYCLE COMMAND signal. - View Dependent Claims (10, 11, 12, 13, 14, 15)
-
Specification