초록 ▼

A mobile X-ray apparatus (20) is disclosed which incorporates a power supply (22) in which the energy for operation of the X-ray tube (21) is supplied from a flywheel (50) coupled to an electrical machine (24) which functions as both a motor and generator. In the motor mode of operation, a controlle

A mobile X-ray apparatus (20) is disclosed which incorporates a power supply (22) in which the energy for operation of the X-ray tube (21) is supplied from a flywheel (50) coupled to an electrical machine (24) which functions as both a motor and generator. In the motor mode of operation, a controller (21) provides power to the machine (24) to operate it as a motor and drive the flywheel up to a desired operating speed. Upon request of the operator to initiate an exposure, the controller power is disconnected from the machine and the power terminals (32) of the machine (24) are connected to a transformer and rectifier (27) which increases the generated voltage and rectifies it to provide the high voltage across the X-ray tube (21) required for proper exposures. The controller (31) provides a first selected level of current to the control winding (77) of the machine (24) required during the motor mode for proper motor operation, and provides a higher selected current level to the control winding (77 ) during generator operation. The controller also provides a boost in the control winding current as the machine (24) begins to supply power during an exposure to compensate for the voltage sag that ordinarily occurs upon loading of the machine to thereby maintain the output voltage substantially constant.

대표청구항 ▼

1. A power supply for providing pulsed power to X-ray generating equipment comprising: (a) a flywheel mounted for rotation; (b) an electrical rotating machine having a rotor coupled by a shaft to the flywheel, a stator power winding, a rotor control winding, power terminals electrically coupled

1. A power supply for providing pulsed power to X-ray generating equipment comprising: (a) a flywheel mounted for rotation; (b) an electrical rotating machine having a rotor coupled by a shaft to the flywheel, a stator power winding, a rotor control winding, power terminals electrically coupled to the power winding and control terminals electrically coupled to the control winding; (c) control power means connected to the control terminals of the electrical machine for supplying a selected control current to the control winding during operation of the electrical machine as a motor and for supplying a selected control current to the control winding when the machine is operated as a generator; (d) motor drive means selectively connectable to the power terminals of the electrical machine for providing a varying electrical voltage to the power terminals at a frequency and phase selected to drive the rotor of the machine and the flywheel connected therewith; and (e) motor-generator mode select switch means, connected to the power terminals of the electrical machine and to the output power of the motor drive means and having output lines, for responding to control signals to selectively connect the power terminals of the electrical machine to the motor drive means during a motor mode and for responding to a control signal to selectively disconnect the power terminals of the electrical machine from the motor drive means and to connect the power terminals to the output lines during a generator mode. 2. The X-ray power supply of claim 1 including exposure timer means, responsive to a signal from an operator to initiate exposure, for providing a control signal to the mode select switch means to switch connection of the power terminals of the electrical machine from the motor drive means to the output lines and for providing a signal to the mode select switch means a selected period of time later corresponding to the termination of the X-ray exposure to disconnect the electrical machine power terminals from the output lines. 3. The X-ray power supply of claim 1 wherein the electrical machine has polyphase stator windings and wherein the motor drive means includes: (a) means for sensing the position of the rotor shaft and providing a signal indicative thereof; and (b) means for receiving the signal indicative of rotor shaft position and providing output signals equal in number to the number of stator phase windings, each of the output signals being in the form of pulses of voltage extending over a selected portion of the revolution of the rotor, the output signal pulses for each of the phase windings being spaced in phase at regular intervals to cover the entire revolution of the rotor and supplied to the stator phase windings such that the voltages across the phase windings cooperate to provide a magnetic field from the stator rotating in synchrony with the rotor. 4. The X-ray power supply of claim 3 wherein the means for sensing rotor shaft position comprises light reflective sectors on the flywheel and a plurality of optical sensors cooperating with the light reflective sectors on the flywheel to provide electrical pulses from each of the sensors as the light reflective sectors on the flywheel rotate past the sensors. 5. The X-ray power supply of claim 3 including means for sensing rotor shaft speed and providing an output signal indicative thereof, and wherein the motor drive means is responsive to the signal indicative of rotor shaft speed to advance the phase of the pulses of voltage applied to the stator windings with respect to rotor shaft position as the rotor speed increases. 6. The X-ray power supply of claim 3 wherein the motor drive means includes means for increasing the power available for supply to the stator windings in the pulses of voltage applied to the windings as the rotor speed increases. 7. The X-ray power supply of claim 1 wherein the control power means is responsive to a signal provided by an operator to increase the current in the control winding to a level selected to provide a desired open circuit output voltage on the power terminals of the electrical machine after a characteristic rise time, whereafter the power terminals of the machine may be connected to a load, and wherein the control power means provides a step increase in current through the control winding a selected period of time before a load is connected to the power terminals to provide a compensatory increase in output voltage to substantially cancel the effect of the sag in output voltage at the power terminals upon connection of the load. 8. The X-ray power supply of claim 7 wherein the control power means is adjustable by an operator to provide a current through the control winding selectable by the operator such that the voltage output at the power terminals of the electrical machine is sufficient to produce a desired kVp level in an X-ray machine. 9. A power supply for providing pulsed power to X-ray generating equipment comprising: (a) a flywheel mounted for rotation; (b) an electrical rotating machine having a rotor coupled by a shaft to the flywheel, a stator power winding, a rotor control winding, power terminals electrically coupled to the power winding and control terminals electrically coupled to the control winding; and (c) control power means, responsive to a signal from the operator requesting an exposure, for providing a control current through the control winding of the electrical machine such that the output voltage at the power terminals of the machine reaches a desired output level after a characteristic rise time, and for applying an increase in current through the control winding a selected period of time before the X-ray load is connected to the power terminals to provide a rise in output voltage at the power terminals that will substantially compensate for the sag in output voltage occuring upon connection of the X-ray load. 10. The X-ray power supply of claim 9 wherein the control power means supplies a selected control current to the control winding during operation of the electrical machine as a motor and including: motor drive means selectively connectable to the power terminals of the electrical machine for providing a varying electrical voltage to the power terminals at a frequency and phase selected to drive the rotor of the machine and the flywheel connected therewith. 11. The X-ray power supply of claim 10 including motor-generator mode select switch means, connected to the power terminals of the electrical machine and to the output power of the motor drive means and having output lines, for responding to control signals to selectively connect the power terminals of the electrical machine to the motor drive means during a motor mode and for responding to a control signal to selectively disconnect the power terminals of the electrical machine from the motor drive means and to connect the power terminals to the output lines during a generator mode. 12. The X-ray power supply of claim 10 including exposure timer means, responsive to a signal from an operator to initiate exposure, for providing a control signal to the mode select switch means to switch connection of the power terminals of the electrical machine from the motor drive means to the output lines and for providing a signal to the mode select switch means a selected period of time later corresponding to the termination of the X-ray exposure to disconnect the electrical machine power terminals from the output lines. 13. The X-ray power supply of claim 10 wherein the electrical machine has polyphase stator windings and wherein the motor drive means includes: (a) means for sensing the position of the rotor shaft and providing a signal indicative thereof; and (b) means, receiving the signal indicative of rotor shaft position, for providing output signals equal in number to the number of stator phase windings, each of the output signals being in the form of pulses of voltage extending over a selected portion of the revolution of the rotor, the output signal pulses for each of the phase windings being spaced in phase at regular intervals to cover the entire revolution of the rotor and supplied to the stator phase windings such that the voltages across the phase windings cooperate to provide a magnetic field from the stator rotating in synchrony with the rotor. 14. The X-ray power supply of claim 13 wherein the means for sensing rotor shaft position comprises light reflective sectors on the flywheel and a plurality of optical sensors cooperating with the light reflective sectors on the flywheel to provide electrical pulses from each of the sensors as the light reflective sectors on the flywheel rotate past the sensors. 15. The X-ray power supply of claim 13 including means for sensing rotor shaft speed and providing an output signal indicative thereof, and wherein the motor drive means is responsive to the signal indicative of rotor shaft speed to advance the phase of the pulses of voltage applied to the stator windings with respect to rotor shaft position as the rotor speed increases. 16. The X-ray power supply of claim 13 wherein the motor drive means includes means for increasing the power available for supply to the stator windings in the pulses of voltage applied to the windings as the rotor speed increases. 17. The X-ray power supply of claim 9 wherein the control power means is adjustable by an operator to provide a current through the control winding selectable by the operator such that the voltage output at the power terminals of the electrical machine is sufficient to produce a desired kVp level in an X-ray machine. 18. Mobile X-ray generating apparatus comprising: (a) a flywheel mounted for rotation; (b) an electrical rotating machine having a rotor coupled by a shaft to the flywheel, a stator power winding, a rotor control winding, power terminals electrically coupled to the power winding and control terminals electrically coupled to the control winding; (c) an X-ray tube having an anode and a cathode; (d) a transformer having a primary selectively receiving power from the power terminals of the electrical machine and increasing the voltage of the power received to a high voltage level at the secondary thereof; (e) rectifier means for rectifying the AC voltage from the secondary of the transformer to a direct voltage, and connected to provide the rectified high voltage across the anode and cathode of the X-ray tube; (f) control power means connected to the control terminals of the electrical machine for supplying a selected control current to the control winding during operation of the electrical machine as a motor and for supplying another selected control current to the control winding when the machine is operated as a generator; (g) motor drive means selectively connectable to the power terminals of the electrical machine for providing a varying electrical voltage to the power terminals at a frequency and phase selected to drive the rotor of the machine and the flywheel connected therewith; and (h) motor-generator mode select switch means, connected to the power terminals of the electrical machine and to the output power of the motor drive means and having output lines connected to the primary of the transformer, for responding to control signals to selectively connect the power terminals of the electrical machine to the motor drive means and for responding to a control signal to selectively disconnect the power terminals of the electrical machine from the motor drive means and to connect the power terminals to the output lines to apply power to the transformer. 19. The apparatus of claim 18 including exposure timer means, responsive to a signal from an operator to initiate exposure, for providing a control signal to the mode select switch means to switch connection of the power terminals of the electrical machine from the motor drive means to the output lines such that output power is transmitted from the electrical machine to the transformer to apply a high voltage across the X-ray tube, and for providing a signal to the mode select switch means a selected period of time later corresponding to the termination of the X-ray exposure to disconnect the electrical machine power terminals from the output lines. 20. The apparatus of claim 18 wherein the electrical machine has polyphase stator windings and wherein the motor drive means includes: (a) means for sensing the position of the rotor shaft and providing a signal indicative thereof; and (b) means for receiving the signal indicative of rotor shaft position and providing output signals equal in number to the number of stator phase windings, each of the output signals being in the form of pulses of voltage extending over a selected portion of the revolution of the rotor, the output signal pulses for each of the phase windings being spaced in phase at regular intervals to cover the entire revolution of the rotor and supplied to the stator phase windings such that the voltages across the phase windings combine to provide a magnetic field from the stator rotating in synchrony with the rotor. 21. The apparatus of claim 20 wherein the means for sensing rotor shaft position comprises light reflective sectors on the flywheel and a plurality of optical sensors cooperating with the light reflective sectors on the flywheel to provide electrical pulses from each of the sensors as the light reflective sectors on the flywheel rotate past the sensors. 22. The apparatus of claim 20 including means for sensing rotor shaft speed and providing an output signal indicative thereof, and wherein the motor drive means is responsive to the signal indicative of rotor shaft speed to advance the phase of the pulses of voltage applied to the stator windings with respect to rotor shaft position as the rotor speed increases. 23. The apparatus of claim 20 wherein the motor drive means includes means for increasing the power available for supply to the stator windings in the pulses of voltage applied to the windings as the rotor speed increases. 24. The apparatus of claim 18 wherein the control power means is responsive to a signal provided by an operator to increase the current in the control winding to a level selected to provide a desired open circuit output voltage on the power terminals of the electrical machine after a characteristic rise time, whereafter the power terminals of the machine may be connected to the transformer, and wherein the control power means provides a step increase in current through the control winding a selected period of time before the transformer is connected to the power terminals to provide a compensatory increase in output voltage to substantially cancel the effect of the sag in output voltage at the power terminals upon connection of the transformer. 25. The apparatus of claim 24 wherein the control power means is adjustable by an operator to provide a current through the control windings selectable by the operator such that the voltage output at the power terminals of the X-ray machine provides a desired peak voltage level from the rectifier means across the X-ray tube. 26. The apparatus of claim 18 wherein the stator has three phase windings and produces a three phase output at the power terminals, wherein the transformer has a three phase primary winding and wherein the secondary has two sets of three phase windings, the outputs of which are passed through diodes of the rectifier means connected such that one set of secondary windings produces a positive rectified voltage which is applied to the X-ray tube anode and the other set of secondary windings produces a negative rectified voltage which is applied to the X-ray tube cathode. 27. Mobile X-ray generating apparatus comprising: (a) a flywheel mounted for rotation; (b) an electrical rotating machine having a rotor coupled by a shaft to the flywheel, a stator power winding, a rotor control winding, power terminals electrically coupled to the power winding and control terminals electrically coupled to the control winding; (c) an X-ray tube having an anode and a cathode; (d) a transformer having a primary selectively receiving power from the power terminals of the electrical machine and increasing the voltage of the power received to a high voltage level at the secondary thereof; (e) rectifier means for rectifying the AC voltage from the secondary of the transformer to a direct voltage, and connected to provide the rectified high voltage across the anode and cathode of the X-ray tube; and (f) control power means, responsive to a signal from the operator requesting an exposure, for providing a control current through the control winding of the electrical machine such that the output voltage at the power terminals of the machine reaches a desired output level after a characteristic rise time, and for applying an increase in current through the control winding a selected period of time before the primary of the transformer is connected to the power terminals to provide a voltage across the X-ray tube to tend to increase the output voltage at the power terminals to substantially compensate for the sag in output voltage occurring upon connection of the transformer to the power terminals. 28. The apparatus of claim 27 wherein the control power means supplies a selected control current to the control winding during operation of the electrical machine as a motor and including: motor drive means selectively connectable to the power terminals of the electrical machine for providing a varying electrical voltage to the power terminals at a frequency and phase selected to drive the rotor of the machine and the flywheel connected therewith. 29. The apparatus of claim 28 including motor-generator mode select switch means, connected to the power terminals of the electrical machine and to the output power of the motor drive means and having output lines connected to the primary of the transformer, for responding to control signals to selectively connect the power terminals of the electrical machine to the motor drive means during a motor mode and for responding to a control signal to selectively disconnect the power terminals of the electrical machine from the motor drive means and to connect the power terminals to the output lines connected to the primary of the transformer during a generator mode. 30. The apparatus of claim 28 including exposure timer means, responsive to a signal from an operator to initiate exposure, for providing a control signal to the mode select switch means to switch connection of the power terminals of the electrical machine from the motor drive means to the output lines connected to the primary of the transformer to cause an X-ray exposure to be made. 31. The apparatus of claim 28 wherein the electrical machine has polyphase stator windings and wherein the motor drive means includes: (a) means for sensing the position of the rotor shaft and providing a signal indicative thereof; and (b) means, receiving the signal indicative of rotor shaft position, for providing output signals equal in number to the number of stator phase windings, each of the output signals being in the form of pulses of voltage extending over a selected portion of the revolution of the rotor, the output signal pulses for each of the phase windings being spaced in phase at regular intervals to cover the entire revolution of the rotor and supplied to the stator phase winding such that the voltages across the phase windings cooperate to provide a magnetic field from the stator rotating in synchrony with the rotor. 32. The apparatus of claim 31 wherein the means for sensing rotor shaft position comprises light reflective sectors on the flywheel and a plurality of optical sensors cooperating with the light reflective sectors on the flywheel to provide electrical pulses from each of the sensors as the light reflective sectors on the flywheel rotate past the sensors. 33. The apparatus of claim 31 including means for sensing rotor shaft speed and providng an output signal indicative thereof, and wherein the motor drive means is responsive to the signal indicative of rotor shaft speed to advance the phase of the pulses of voltage applied to the stator windings with respect to rotor shaft position as the rotor speed increases. 34. The apparatus of claim 31 wherein the motor drive means includes means for increasing the power available for supply to the stator windings in the pulses of voltage applied to the windings as the rotor speed increases. 35. The apparatus of claim 27 wherein the control power means is adjustable by an operator to provide a current through the control winding selectable by the operator such that the voltage output at the power terminals of the electrical machine is sufficient to produce a desired output voltage from the rectifier means across the anode and cathode of the X-ray tube. 36. The apparatus of claim 27 wherein the stator has three phase windings and produces a three phase output at the power terminals, wherein the transformer has a three phase primary winding and wherein the secondary has two sets of three phase windings, the outputs of which are passed through diodes of the rectifier means connected such that one set of secondary windings produces a positive rectified voltage which is applied to the X-ray tube anode and the other set of secondary windings produces a negative rectified voltage which is applied to the X-ray tube cathode. 37. A method of controlling the voltage supplied by a flywheel driven generator, having stator power windings and a rotor control winding, through a transformer and rectifier to an X-ray tube, comprising the steps of: (a) providing a current through the control winding sufficient to produce a desired open circuit output voltage from the stator windings; (b) connecting the primary of the transformer to the terminals of the stator power windings to supply power from the generator to the X-ray tube; and (c) a selected period of time before connecting the transformer to the stator power windings, increasing the current in the control winding to a level selected to cause the potential increase in output voltage dur to the increased current to substantially cancel the potential decrease in output voltage occurring as the stator power windings of the generator are loaded so that the output voltage remains substantially constant during an X-ray exposure. 38. A power supply for providing pulsed power to X-ray generating equipment comprising: (a) a flywheel mounted for rotation; (b) an electrical rotating machine having a rotor coupled by a shaft to the flywheel, a stator power winding, a rotor control winding, power terminals electrically coupled to the power winding and control terminals electrically coupled to the control winding; (c) control power means connected to the control terminals of the electrical machine for supplying a selected control current to the control winding during operation of the electrical machine as a motor and for supplying a selected control current to the control winding when the machine is operated as a generator, wherein the control power means is responsive to a signal provided by an operator to increase the current in the control winding to a level selected to provide a desired open circuit output voltage on the power terminals of the electrical machine after a characteristic rise time, whereafter the power terminals of the machine may be connected to a load, and wherein the control power means provides a step increase in current through the control winding a selected period of time before a load is connected to the power terminals to provide a compensatory increase in output voltage to substantially cancel the effect of the sag in output voltage at the power terminals upon connection of the load; and (d) motor drive means selectively connectable to the power terminals of the electrical machine for providing a varying electrical voltage to the power terminals at a frequency and phase selected to drive the rotor of the machine and the flywheel connected therewith. 39. The X-ray power supply of claim 38 wherein the control power means is adjustable by an operator to provide a current through the control winding selectable by the operator such that the voltage output at the power terminals of the electrical machine is sufficient to produce a desired kVp level in an X-ray machine. 40. Mobile X-ray generating apparatus comprising: (a) a flywheel mounted for rotation; (b) an electrical rotating machine having a rotor coupled by a shaft to the flywheel, polyphase stator power windings, a rotor control winding, power terminals electrically coupled to the power windings and control terminals electrically coupled to the control winding; (c) an X-ray tube having an anode and a cathode; (d) a transformer having a primary selectively receiving power from the power terminals of the electrical machine and increasing the voltage of the power received to a high voltage level at the secondary thereof; (e) rectifier means for rectifying the AC voltage from the secondary of the transformer to a direct voltage, and connected to provide the rectified high voltage across the anode and cathode of the X-ray tube; (f) control power means connected to the control terminals of the electrical machine for supplying a selected control current to the control winding during operation of the electrical machine as a motor and for supplying another selected control current to the control winding when the machine is operated as a generator; and (g) motor drive means selectively connectable to the power terminals of the electrical machine for providing a varying electrical voltage to the power terminals at a frequency and phase selected to drive the rotor of the machine and the flywheel connected therewith, the motor drive means including: (1) means for sensing the position of the rotor shaft and providing a signal indicative thereof; and (2) means for receiving the signal indicative of rotor shaft position and providing output signals equal in number to the number of stator phase windings, each of the output signals being in the form of pulses of voltage extending over a selected portion of the revolution of the rotor, the output signal pulses for each of the phase windings being spaced in phase at regular intervals to cover the entire revolution of the rotor and supplied to the stator phase windings such that the voltages across the phase windings combine to provide a magnetic field from the stator rotating in synchrony with the rotor. 41. The apparatus of claim 40 wherein the means for sensing rotor shaft position comprises light reflective sectors on the flywheel and a plurality of optical sensors cooperating with the light reflective sectors on the flywheel to provide electrical pulses from each of the sensors as the light reflective sectors on the flywheel rotate past the sensors. 42. The apparatus of claim 40 including means for sensing rotor shaft speed and providing an output signal indicative thereof, and wherein the motor drive means is responsive to the signal indicative of the rotor shaft speed to advance the phase of the pulses of voltage applied to the stator windings with respect to rotor shaft position as the rotor speed increases. 43. The apparatus of claim 40 wherein the motor drive means includes means for increasing the power available for supply to the stator windings in the pulses of voltage applied to the windings as the rotor speed increases. 44. Mobile X-ray generating apparatus comprising: (a) a flywheel mounted for rotation; (b) an electrical rotating machine having a rotor coupled by a shaft to the flywheel, a stator power winding, a rotor control winding, power terminals electrically coupled to the power winding and control terminals electrically coupled to the control winding; (c) an X-ray tube having an anode and a cathode; (d) a transformer having a primary selectively receiving power from the power terminals of the electrical machine and increasing the voltage of the power received to a high voltage level at the secondary thereof; (e) rectifier means for rectifying the AC voltage from the secondary of the transformer to a direct voltage, and connected to provide the rectified high voltage across the anode and cathode of the X-ray tube; (f) control power means connected to the control terminals of the electrical machine for supplying a selected control current to the control winding during operation of the electrical machine as a motor and for supplying another selected control current to the control winding when the machine is operated as a generator, wherein the control power means is responsive to a signal provided by an operator to increase the current in the control winding to a level selected to provide a desired open circuit output voltage on the power terminals of the electrical machine after a characteristic rise time, whereafter the power terminals of the machine may be connected to a transformer, and wherein the control power means provides a step increase in current through the control winding a selected period of time before the transformer is connected to the power terminals to provide a compensatory increase in output voltage to substantially cancel the effect of the sag in output voltage at the power terminals upon connection of the transformer; and (g) motor drive means selectively connectable to the power terminals of the electrical machine for providing a varying electrical voltage to the power terminals at a frequency and phase selected to drive the rotor of the machine and the flywheel connected therewith. 45. The apparatus of claim 44 wherein the control power means is adjustable by an operator to provide a current through the control windings selectable by the operator such that the voltage output at the power terminals of the X-ray machine provides a desired peak voltage level from the rectifier means across the X-ray tube. 46. Mobile X-ray generating apparatus comprising: (a) a flywheel mounted for rotation; (b) an electrical rotating machine having a rotor coupled by a shaft to the flywheel, three phase stator power windings producing a three phase output, a rotor control winding, three phase power terminals electrically coupled to the power windings and control terminals electrically coupled to the control winding; (c) an X-ray tube having an anode and a cathode; (d) a transformer having a three phase primary winding selectively receiving power from the power terminals of the electrical machine and increasing the voltage of the power received to a high voltage level at the secondary thereof, the secondary having two sets of three phase windings; (e) rectifier means for rectifying the AC voltage from the secondary of the transformer to a direct voltage, and connected to provide the rectified high voltage across the anode and cathode of the X-ray tube, the rectifier means having diodes connected such that the output of one set of transformer secondary windings is rectified to produce a positive rectified voltage which is applied to the X-ray tube anode and such that the output of the other set of transformer secondary windings is rectified to produce a negative rectified voltage which is applied to the X-ray tube cathode; (f) control power means connected to the control terminals of the electrical machine for supplying a selected control current to the control winding during operation of the electrical machine as a motor and for supplying another selected control current to the control winding when the machine is operated as a generator; and (g) motor drive means selectively connectable to the power termains of the electrical machine for providing a varying electrical voltage to the power terminals at a frequency and phase selected to drive the rotor of the machine and the flywheel connected therewith.