Solid-state power supply system for rotating anode x-ray tubes

Claim 2

An induction motor supply system such as used for powering rotating anode X-ray tubes, wherein the X-ray tube anode is either driven by the motor rotor or is the motor rotor, said power supply system comprising a first solid-state power source for supplying normal power required for driving the rotor of said motor at a first running speed, a second solidstate power source for supplying normal power required for driving the rotor of said motor at a second running speed, said second speed being higher than said first speed, boost means for increasing the power to the motor for a predetermined period of time above the normal running power to accelerate the rotor while attaining said first and second running speeds, means for decreasing said power to the normal running power after said predetermined period of time, and means for selectively connecting the stator of said motor to either said first or said second power sources.

Claim 3

The power supply system of claim 1 wherein boost timing means are provided for automatically limiting the operating time of said boost means.

Claim 4

The power supply of claim 1 wherein means are provided for monitoring said boost means to ascertain operation thereof.

Claim 5

The power supply system of claim 1 wherein said first solid-state power source means comprises control transformer means for coupling to a power line to provide low voltage at line frequency, means for coupling said line frequency signal from the secondary of said control transformer to first solid-state phase shift means, said last-named phase shift means for phase shifting said line frequency, means using the phase shifted line frequency to control a silicon-controlled rectifier bridge circuit so that the firing angles of the two silicon controlled rectifiers of the bridge circuit provide a boost power output from said bridge circuit and a running power output from said bridge circuit by varying the phase shift of said line frequency phase shift network means, and means for selectively connecting the output of said silicon controlled rectifier to the stator of said induction motor.

Claim 6

The power supply system of claim 4 including timing means for limiting the time of the phase shift resulting in the boost power to thereby automatically vary the phase shift after a first timer period.

Claim 7

An induction motor power supply system such as used for rotating the anode of X-ray tubes, wherein the X-ray tube anode is either driven by the rotor of the induction motor or is the induction motor rotor, said power supply system comprising a first solid state power source for supplying normal power required foR driving the rotor of said motor at a first running speed, a second solid state power source for supplying normal power for driving the rotor of said motor at a second running speed, said second speed being higher than said first speed, boost means for increasing the power to the motor for a predetermined period of time above the normal running power to accelerate the motor while attaining said first and second running speeds, means for decreasing said power to the normal running power after said predetermined period of time, means for selectively connecting the stator of said motor to either said first or said second power sources, and braking means for braking said motor when switching from said second speed.

Claim 8

An induction motor power supply system such as used for rotating the anode of X-ray tubes, wherein the X-ray tube anode is either driven by the rotor of the induction motor or is the induction motor rotor, said power supply system comprising a first solid state power source for supplying normal power required foR driving the rotor of said motor at a first running speed, a second solid state power source for supplying normal power for driving the rotor of said motor at a second running speed, said second speed being higher than said first speed, boost means for increasing the power to the motor for a predetermined period of time above the normal running power to accelerate the motor while attaining said first and second running speeds, means for decreasing said power to the normal running power after said predetermined period of time, means for selectively connecting the stator of said motor to either said first or said second power sources, and braking means for braking said motor when switching from said second speed.

Claim 9

The power supply system of claim 6 wherein braking timing means are provided for automatically limiting the operating time of said braking means.

Claim 10

The power supply system of claim 6 wherein said braking means comprises a braking relay, means for operating said braking relay responsive to switching off said second solid-state power source, means responsive to the operation of said braking means for deaccelerating the speed of the anode from said second speed to said first speed, and said last-named means comprising means responsive to the operation of the braking relay for operating said first solid-state power source at a boost power condition.

Claim 11

The power supply means of claim 8 wherein means are provided automatically time limiting the operating period of said braking relay, whereby said second power source is returned to the running power condition from the boost power condition at the end of a defined time period.

Claim 12

An induction motor power supply system such as used for powering the rotating anode of X-ray tubes, wherein the X-ray tube anode is either driven by the motor rotor or is the motor rotor, said power supply system comprising a first solid-state power source for driving the rotor of said motor at a first running speed, a second solid-state power source for driving the rotor of said motor at a second speed, said second speed being higher than said first speed, boost means for accelerating the rotor to said first and second speeds, means for selectively connecting the stator of said motor to either said first or said second power source, control transformer means for coupling to a power line to provide line frequency power, AC-to-DC power supply means coupled to the secondary of said control transformer for supplying direct current power, oscillator means powered from said direct current power for providing a signal having a frequency greater than the line frequency, inverter means driven by said oscillator means to provide a driving power at a frequency higher than line frequency for driving the said rotor, and means for automatically restarting said inverter is said inverter is extinguished.

Claim 13

An induction motor power supply system such as used for powering the rotating anode of X-ray tubes, wherein the X-ray tube anode is either driven by the motor rotor or is the motor rotor, said power supply system comprising a first solid-state power source for driving the rotor of said motor at a first running speed, a second solid-state power source for driving the rotor of said motor at a second speed, said second speed being higher than said first speed, boost means for accelerating the rotor to said first and second speeds, means for selectively connecting the stator of said motor to either said first or said second power source, control transformer means for coupling to a power line to provide line frequency power, AC-to-DC power supply means coupled to the secondary of said control transformer for supplying direct current power, oscillator means powered from said direct current power for providing a signal having a frequency greater than the line frequency, inverter means driven by said oscillator means to provide a driving power at a frequency higher than line frequency for driving the said rotor, and means for automatically restarting said inverter is said inverter is extinguished.

Claim 14

The power supply system of claim 10 wherein said inverter comprises a silicon-controlled rectifier inverter having a first and a second SCR, said first and second SCRs normally operating individually, said oscillator means including inverter driver means having a pair of outputs, each of said outputs being individually coupled to one of the gates of said SCRs alternatively gating said silicon-controlled rectifiers, AC-to-DC converter means coupled to said line power, the output of said AC-to-DC converter means being connected across said first and second SCRs, and said means for restarting said inverter comprising restarting relay coil means connected across the output of said AC-to-DC converter means to keep said restarting relay energized unless both SCRs are gated simultaneously, restarting normally open relay contact means in series with the output of said AC-to-DC converter means for decoupling said AC-to-DC converter means from said silicon-controlled rectifier inverter in the event both of said silicon-controlled rectifiers are gated simultaneously, thereby removing power from the silicon-controlled rectifier inverter means and automatically reenergizing said restarting relay to reconnect said inverter means to said AC-to-DC converter means.

Claim 15

The induction motor power supply system of claim 11 wherein said boost means comprises means individual to said second solid-state power source for providing a boosted power output from said second solid-state power source for accelerating the anode so that it reaches the second speed in a relatively small time period.

Claim 16

The power supply system of claim 12 wherein the AC-to-DC converter means comprises a pair of silicon-controlled rectifiers, and wherein the boost means individual to said second solid-state power source comprises phase shift network means coupled to the secondary of said control transformer, the output of said phase shift network being coupled to said AC-to-DC converter means for determining the firing angles of the silicon controlled rectifiers in said AC-to-DC converter means and thereby determining the power output from said AC-to-DC converter means.

Claim 17

The power supply system of claim 13 including timing means for automatically changing the phase shift after a first period of time to reduce the boosted power to normal running power.

Claim 18

An induction motor power supply system such as used for rotating the anode of X-ray tubes, wherein the X-ray tube anode is either driven by the motor rotor or is the motor rotor, said power supply system comprising a first solid-state power source for driving the rotor of said motor at a first speed, a second solid-state power source for driving the rotor of said motor at a second speed, said second speed being higher than said first speed, boost means for accelerating the rotor to said first and second speeds, second solid-state power source switching means for initiating the operation of said second solid-state power source, means for selectively connecting the stator of said motor to either said first or said second power source comprising selection switching means operated responsive to the operation of second solid-state switching means, and means responsive to the operation of said selection switching means for switching the coupling of the stator of the induction motor from the output of said first solid-state power source to the output of said second solid-state power source.

Claim 19

An induction motor power supply system such as used for rotating the anode of X-ray tubes, wherein the X-ray tube anode is either driven by the motor rotor or is the motor rotor, said power supply system comprising a first solid-state power source for driving the rotor of said motor at a first speed, a second solid-state power source for driving the rotor of said motor at a second speed, said second speed being higher than said first speed, boost means for accelerating the rotor to said first and second speeds, second solid-state power source switching means for initiating the operation of said second solid-state power source, means for selectively connecting the stator of said motor to either said first or said second power source comprising selection switching means operated responsive to the operation of second solid-state switching means, and means responsive to the operation of said selection switching means for switching the coupling of the stator of the induction motor from the output of said first solid-state power source to the output of said second solid-state power source.

Claim 20

The power supply system of claim 15 wherein said selection switching means comprises a selection relay, and wherein said second solid-state power source switching means comprises a second solid-state power source relay means, normally open contacts on said second solid-state power source relay means operating to complete an operating circuit for said selection relay.

Claim 21

The power supply system of claim 16 wherein split phase start capacitor means are provided for said induction motor, said split phase capacitor means comprising a first and a second capacitor, means including contacts on said selection relay for connecting said first and second capacitors in parallel when said first power source is connected to the stator of said motor, means including contacts on said switching relay for disconnecting said first capacitor responsive to said second solid-state power source being coupled to the stator of said induction motor.

Claim 22

An induction motor supply system such as used for powering X-ray tubes having rotating anodes, wherein the X-ray tube anode is either driven by the motor rotor or is the motor rotor, said power supply system comprising a first solid-state power source for driving the motor of said rotor at a first speed, a second solid-state power source for driving the rotor of said motor at a second speed, said second speed being higher than said first running speed, boost means for increasing the power to the motor above the normal runNing power to accelerate the rotor while obtaining the first and second running speeds, means for selectively connecting the stator of said motor to either said first or said second power sources, and means for monitoring said boost means to ascertain operation thereof, said monitoring means comprising a combination of series and parallel relays at the interconnection to said stator for determining a boost power condition, monitoring relay means operated responsive to the operation of said series and parallel relay combination to demonstrate the boost power condition.

Claim 23

An induction motor supply system such as used for powering X-ray tubes having rotating anodes, wherein the X-ray tube anode is either driven by the motor rotor or is the motor rotor, said power supply system comprising a first solid-state power source for driving the motor of said rotor at a first speed, a second solid-state power source for driving the rotor of said motor at a second speed, said second speed being higher than said first running speed, boost means for increasing the power to the motor above the normal runNing power to accelerate the rotor while obtaining the first and second running speeds, means for selectively connecting the stator of said motor to either said first or said second power sources, and means for monitoring said boost means to ascertain operation thereof, said monitoring means comprising a combination of series and parallel relays at the interconnection to said stator for determining a boost power condition, monitoring relay means operated responsive to the operation of said series and parallel relay combination to demonstrate the boost power condition.