公开(公告)号：US5265146A

公开(公告)日：1993-11-23

申请号：US976765

申请日：1992-11-16

申请人： William F. Wirth ,  Gerald K. Flakas

发明人： William F. Wirth ,  Gerald K. Flakas

IPC分类号： H05G1/66

CPC分类号： H05G1/66

摘要： An x-ray tube rotor controller uses the main high voltage inverters for acceleration and speed maintenance. The rotor controller includes a DC voltage source, and a rotary anode drive circuit including a rotary anode motor designed as a two-winding induction motor. The rotor controller comprises first and second inverter circuits which may be either half bridge or full bridge arrangements, the first and second inverter circuits for accelerating the anode, and further for generating high voltage for the x-ray tube. Electronic switching means allow for instantaneous electronic switching of the output of the first and second inverter circuits between the high voltage power supply and the anode motor. A phase switching capacitor may be used to provide the other phase of the motor.

摘要翻译： X射线管转子控制器使用主高压逆变器进行加速和速度维护。 转子控制器包括直流电压源和包括设计为双绕组感应电动机的旋转阳极电动机的旋转阳极驱动电路。 转子控制器包括可以是半桥或全桥布置的第一和第二反相器电路，用于加速阳极的第一和第二反相器电路，并且还用于产生用于X射线管的高电压。 电子开关装置允许在高压电源和阳极电动机之间的第一和第二逆变器电路的输出的瞬时电子切换。 可以使用相位切换电容器来提供电动机的另一相。

公开(公告)号：US5451878A

公开(公告)日：1995-09-19

申请号：US276149

申请日：1994-07-15

申请人： William F. Wirth ,  Thomas G. McFarland

发明人： William F. Wirth ,  Thomas G. McFarland

IPC分类号： A61B5/055 ,  G01R33/385 ,  G01R33/28

CPC分类号： G01R33/3852

摘要： A gradient amplifier for an MRI system includes a low voltage amplifier and high voltage amplifier connected in series circuit with a gradient coil. A gradient current command pulse causes the low voltage amplifier to produce the desired coil current and the same command is differentiated to provide a voltage command for the high voltage amplifier which causes it to deliver power to rapidly build the gradient field at the beginning of the pulse and to remove power at the conclusion of the pulse. Two embodiments disclose different strategies for maintaining the high voltage power supply fully charged throughout a scan.

摘要翻译： 用于MRI系统的梯度放大器包括与梯度线圈串联连接的低压放大器和高压放大器。 梯度电流指令脉冲使低电压放大器产生所需的线圈电流，并且相同的指令被微分，以为高压放大器提供电压指令，这使得其在脉冲开始处传递功率以快速建立梯度场 并在脉冲结束时消除电力。 两个实施例公开了在整个扫描期间保持高电压电源完全充电的不同策略。

公开(公告)号：USRE34107E

公开(公告)日：1992-10-20

申请号：US648452

申请日：1991-01-30

申请人： William F. Wirth

发明人： William F. Wirth

IPC分类号： H03K17/082

CPC分类号： H03K17/0828

摘要： A gate drive circuit for an insulated gate bipolar transistor initially drives the gate to a first voltage potential which causes the transistor to partially turn on. A sensor detects when the transistor saturates at which point the gate drive voltage is increased to increase the conductivity of the transistor and reduce its saturation voltage drop. If, however, a load coupled to the transistor is short circuited, the transistor will never reach saturation and will remain partially turned on at a point where it has increased short circuit current handling capability. In addition, once the transistor has been fully turned on, should a short circuit load condition occur, the transistor will drop out of saturation causing the drive circuit to reduce the gate voltage to increase the short circuit current handling capability of the transistor.

公开(公告)号：US4954917A

公开(公告)日：1990-09-04

申请号：US336931

申请日：1989-04-12

申请人： William F. Wirth

发明人： William F. Wirth

IPC分类号： G05F1/56 ,  G05F1/613 ,  H03K17/082

CPC分类号： H03K17/0828

摘要： A gate drive circuit for an insulated gate bipolar transistor initially drives the gate to a first voltage potential which causes the transistor to partially turn on. A sensor detects when the transistor saturates, at which point the gate drive voltage is increased to increase the conductivity of the transistor and reduce its saturation voltage drop. If, however, a load coupled to the transistor is short circuited, the transistor will never reach saturation and will remain partially turned on at a point where it has increased short circuit current handling capability. In addition, once the transistor has been fully turned on, should a short circuit load condition occur, the transistor will drop out of saturation causing the drive circuit to reduce the gate voltage to increase the short circuit current handling capability of the transistor.

公开(公告)号：US5270657A

公开(公告)日：1993-12-14

申请号：US965131

申请日：1992-10-22

申请人： William F. Wirth ,  Thomas G. McFarland ,  Robert M. Vavrek ,  Peter B. Roemer ,  Otward M. Mueller ,  John N. Park

发明人： William F. Wirth ,  Thomas G. McFarland ,  Robert M. Vavrek ,  Peter B. Roemer ,  Otward M. Mueller ,  John N. Park

IPC分类号： G01R33/385 ,  G01V3/00

CPC分类号： G01R33/3852

摘要： A gradient amplifier for use in magnetic resonance imaging equipment employs a low voltage DC power supply connected in series between a pair of higher voltage DC power supplies, the latter supplies serving to provide increased power for rapid gradient switching and the former supply providing correction current to produce the desired voltage output. The high voltage DC power supplies preferably comprise multiple DC units which can be combined to provide finer steps of control prior to correction by the lower voltage supply. The low voltage DC power supply preferably comprise one or more linear amplifiers connected in series, or one or more switchmode amplifiers connected in series. The DC power supplies are controlled in an open loop manner from a gradient signal that designates the desired current for the gradient coil and the amplifiers are operated in a closed loop responding to to a feedback signal from the gradient coil.

摘要翻译： 用于磁共振成像设备的梯度放大器采用串联连接在一对高压直流电源之间的低压直流电源，后者用于为快速梯度切换提供增加的功率，而前一个电源提供校正电流 产生所需的电压输出。 高压DC电源优选地包括多个DC单元，其可以组合以在由较低电压源进行校正之前提供更精细的控制步骤。 低压DC电源优选地包括串联连接的一个或多个线性放大器或串联连接的一个或多个开关模式放大器。 直流电源由开路环路控制，该梯度信号指定用于梯度线圈的期望电流，并且放大器响应于来自梯度线圈的反馈信号在闭环中工作。

公开(公告)号：US5159697A

公开(公告)日：1992-10-27

申请号：US629528

申请日：1990-12-18

申请人： William F. Wirth

发明人： William F. Wirth

IPC分类号： H05G1/06 ,  H01J35/16 ,  H05G1/08 ,  H05G1/10 ,  H05G1/54 ,  H05G1/66

CPC分类号： H01J35/16 ,  H05G1/08 ,  H05G1/54 ,  H05G1/66 ,  H01J2235/168

摘要： An X-ray imaging apparatus has a vacuum tube with an envelope that contains an anode, a cathode and a filament. A motor has a rotor mechanically connected to the anode inside the envelope and a stator on the exterior of the envelope. The vacuum tube and the motor are enclosed in an electrically conductive casing which are grounded. A grounded shield of a conductive material is placed between the stator and the envelope to suppress high voltage discharges within the envelope from producing currents in a winding of the stator. Low pass filters are placed in series with each conductor between the vacuum tube and a power supply to suppress radio frequency signals produced by the high voltage discharges from being carried over the conductors.

公开(公告)号：US08374011B2

公开(公告)日：2013-02-12

申请号：US12859949

申请日：2010-08-20

申请人： William F. Wirth

发明人： William F. Wirth

IPC分类号： H02M7/537

CPC分类号： H02M7/53873 ,  H02M7/49 ,  H02M7/493

摘要： A power converter includes at least two power conversion sections operating in parallel. The power converter receives a variable input power and generates an AC output voltage. When the power source is generating enough power to supply a DC voltage to the power converter greater than or equal to the peak magnitude of the desired AC voltage output, each power conversion section operates in parallel, converting the DC voltage to the desired AC voltage output. When the power generated by the variable power source results in a DC voltage having a magnitude less than the peak magnitude of the desired AC voltage output, the power conversion sections operate in series. One power conversion section operates as a boost converter to boost the DC voltage level to a suitable level for the second power conversion section, which generates the desired AC output voltage.

摘要翻译： 功率转换器包括并行操作的至少两个功率转换部。 功率转换器接收可变输入功率并产生AC输出电压。 当电源产生足够的功率以向功率转换器提供大于或等于所需AC电压输出的峰值幅度的DC电压时，每个功率转换部分并联工作，将DC电压转换为期望的AC电压输出 。 当由可变电源产生的电力导致具有小于期望的AC电压输出的峰值幅度的DC电压时，功率转换部分串联工作。 一个电源转换部分用作升压转换器，以将直流电压电平升高到用于产生所需AC输出电压的第二电力转换部分的适当电平。

公开(公告)号：US5132999A

公开(公告)日：1992-07-21

申请号：US647872

申请日：1991-01-30

申请人： William F. Wirth

发明人： William F. Wirth

IPC分类号： H05G1/08 ,  H05G1/10 ,  H05G1/54

CPC分类号： H05G1/10 ,  H05G1/08 ,  H05G1/54

摘要： An X-ray imaging system includes an vacuum tube, which is biased by a high voltage power supply connected to the tube by two shielded cables. The cables collectively have a plurality of conductors which are coupled at one end to the high voltage power supply. The other end of each conductor is coupled to a component of the vacuum tube by a separate inductor. During a voltage breakdown of the vacuum tube, the inductors depress electrical current flow between the anode and the cathode of the tube to reduce the erosion of tube components which results from the discharge. This current is in part due to the energy stored in the cable, which is not depressed by conventional current limiting circuits in the high voltage power supply. Voltage limiting devices connected to the tube prevent ringing in the cables from generating excessively high voltage levels.

公开(公告)号：US4375612A

公开(公告)日：1983-03-01

申请号：US270740

申请日：1981-06-05

申请人： William F. Wirth

发明人： William F. Wirth

IPC分类号： H02M7/162 ,  H02M7/757 ,  H02P23/06 ,  H02P7/44

CPC分类号： H02M7/757 ,  H02M7/1626 ,  H02P23/06

摘要： A-C energy, from an a-c power system, is converted by a phase-controlled SCR rectifier bridge, which is followed by a series-connected filter choke and a shunt-connected filter capacitor, to d-c power for delivery via a d-c bus to a load, such as an inverter and an a-c induction motor driven by the inverter. When there is a decrease in load demand, for example when the motor speed is to be reduced, fast speed control is obtained by regenerating power back into the a-c power system from the load. Power flow through the d-c power supply is reversed by means of a switching network, interposed between the filter choke and capacitor, having a pair of reverse SCR's for cross-coupling the positive and negative lines of the d-c bus. When the reverse SCR's are fired into conduction, the connections between the filter capacitor and the bridge's output terminals are effectively reversed, thereby facilitating power flow from the load to the a-c power system.

摘要翻译： 来自交流电源系统的交流电能由相控SCR整流桥转换，后者是串联连接的滤波扼流圈和并联滤波电容，以将直流电源通过直流母线传送到负载 ，如变频器和由变频器驱动的交流感应电动机。 当负载需求减少时，例如当电机速度降低时，可以通过从负载再生电源到a-c电力系统来获得快速的速度控制。 通过d-c电源的电流通过插在滤波器扼流圈和电容器之间的开关网络来反转，具有一对用于交叉耦合d-c总线的正极和负极线的反向SCR。 当反向SCR被触发导通时，滤波电容器和桥的输出端子之间的连接被有效地反向，从而有助于从负载到a-c电力系统的功率流。

公开(公告)号：US20120044731A1

公开(公告)日：2012-02-23

申请号：US12859949

申请日：2010-08-20

申请人： William F. Wirth

发明人： William F. Wirth

IPC分类号： H02M7/5387

CPC分类号： H02M7/53873 ,  H02M7/49 ,  H02M7/493

摘要： A power converter includes at least two power conversion sections operating in parallel. The power converter receives a variable input power and generates an AC output voltage. When the power source is generating enough power to supply a DC voltage to the power converter greater than or equal to the peak magnitude of the desired AC voltage output, each power conversion section operates in parallel, converting the DC voltage to the desired AC voltage output. When the power generated by the variable power source results in a DC voltage having a magnitude less than the peak magnitude of the desired AC voltage output, the power conversion sections operate in series. One power conversion section operates as a boost converter to boost the DC voltage level to a suitable level for the second power conversion section, which generates the desired AC output voltage.

摘要翻译： 功率转换器包括并行操作的至少两个功率转换部。 功率转换器接收可变输入功率并产生AC输出电压。 当电源产生足够的功率以向功率转换器提供大于或等于所需AC电压输出的峰值幅度的DC电压时，每个功率转换部分并联工作，将DC电压转换为期望的AC电压输出 。 当由可变电源产生的电力导致具有小于期望的AC电压输出的峰值幅度的DC电压时，功率转换部分串联工作。 一个电源转换部分用作升压转换器，以将直流电压电平升高到用于产生所需AC输出电压的第二电力转换部分的适当电平。