With Automatic Control Of The Magnitude Of Output Voltage Or Current Patents (Class 363/25)
  • Patent number: 6449172
    Abstract: A power supply apparatus includes a variable frequency oscillating circuit, a driver, a soft start circuit, switching elements for receiving a switching signal, a resonating capacitor connected at a connection point of the switching elements via a primary coil of a transformer, a rectifying circuit provided at a secondary coil of the transformer, an amplifier for comparing an output voltage, Vb obtained at the rectifying circuit and a reference voltage, Vref, a photo-coupler for controlling an impedance of an oscillating element of a variable frequency oscillating circuit based on the comparison output, and a charge voltage control circuit for controlling an oscillation frequency when the variable oscillation circuit is initially driven. A frequency control signal when power is ON is made nonlinear relative to time. As a result, a change in oscillation frequency immediately after power is ON is made gentle, and a rapid change in current that flows in a primary coil is eliminated.
    Type: Grant
    Filed: December 26, 2000
    Date of Patent: September 10, 2002
    Assignee: Sony Corporation
    Inventor: Kiyokazu Nagahara
  • Patent number: 6445599
    Abstract: Ripple canceling, soft switching isolated DC/DC converters with reduced voltage stress synchronous rectification. The converters include interleaved switching converters providing power to a node supplying power to a zero volt switching bi-phase power conversion stage driving synchronous rectifiers feeding an output filter. In one embodiment, the interleaved converters are boost mode converters operating in continuous conduction mode boost converters. Various embodiments are disclosed.
    Type: Grant
    Filed: March 29, 2001
    Date of Patent: September 3, 2002
    Assignee: Maxim Integrated Products, Inc.
    Inventor: Chien Nguyen
  • Publication number: 20020118553
    Abstract: A voltage at a capacitor included in a peak detector is equal to a peak output voltage of a full-wave rectifier. A comparator included in a monitor circuit compares an output voltage of the peak detector with a voltage appearing at the capacitor. The comparator inputs a voltage signal corresponding to a compared result, to a switching controller. The switching controller controls a switching operation of a switching device. A power-factor control circuit controls a charge/discharge operation of the capacitor in accordance with a switching operation of the switching device, in a case where an output voltage of a DC-to-DC converter is equal to or less than reference power Pstd [W]. In the case where the output voltage of the DC-to-DC converter is greater than the reference power, the power-factor control circuit controls the charge/discharge operation by directly supplying the capacitor with a current output from a full-wave rectifier.
    Type: Application
    Filed: February 25, 2002
    Publication date: August 29, 2002
    Inventor: Koichi Morita
  • Patent number: 6434031
    Abstract: Driving a quadrupole mass spectrometer includes obtaining an air core transformer with a primary and a secondary, matching the secondary to the mass spectrometer, and driving the primary based on first and second voltage levels. Driving of the primary is via an isolating stage that minimizes low level drive signal coupling.
    Type: Grant
    Filed: March 20, 2001
    Date of Patent: August 13, 2002
    Assignee: California Institute of Technology
    Inventors: Ara Chutjian, Dean Aalami, Murray Darrach, Otto Orient
  • Publication number: 20020085395
    Abstract: The switched power converter comprises a first rectifier module (11-1) connected to a first capacitor (11-2) that, in turn, is connected to an excitation module (11-3) that applies a voltage to some input terminals (PT-1, PT-2) of a piezoelectric transformer (PT).
    Type: Application
    Filed: December 20, 2001
    Publication date: July 4, 2002
    Applicant: ALCATEL
    Inventors: Jose Andres Navas Sabater, Mercedes Rivas Saiz, Juan Diaz Gonzalez, Juan Martin Ramos, Fernando Nuno Garcia, Miguel Jose Prieto
  • Publication number: 20020080627
    Abstract: An isolated power controller for regulating 0 to full voltage, wherein the output is fully regulated, the power is bi-directional, and the output of the IPC is fed into an LC averaging filter.
    Type: Application
    Filed: December 5, 2001
    Publication date: June 27, 2002
    Inventors: David F. Baretich, Gregory P. Wiegand
  • Publication number: 20020075700
    Abstract: There is provided a switching power supply unit that is capable of performing zero-voltage switching in the entire load region to reduce switching loss and noise and improve the voltage transmission efficiency. The switching power supply unit is comprised of a main switching device, and an auxiliary switching device for controlling resonance so as to prevent power loss accompanying a switching action of the main switching device. A control circuit varies the OFF period during which the main switching device and the auxiliary switching device are ON simultaneously, according to power consumption by a load on an apparatus in which the switching power supply unit is installed.
    Type: Application
    Filed: September 24, 2001
    Publication date: June 20, 2002
    Inventor: Takashi Birumachi
  • Publication number: 20020034085
    Abstract: A resonant reset dual switch forward converter is disclosed. The resonant reset dual switch forward converter includes an input for accepting a DC voltage; a transformer having a primary winding and a secondary winding; a first and a second switch connected in series with the primary winding of the transformer for periodically connecting the input to the primary winding; a resonant capacitor for resetting the transformer during the OFF time of the first and second switches; and an auxiliary switch remaining OFF during the ON time of the first and second switches, and connecting the primary winding to the resonant capacitor during the OFF time of the first and second switches. The resonant reset dual switch forward converter provides a switching duty cycle greater than 50%, obtains a zero-voltage-switching condition for the first and second switches, and maintains the voltage stress of the first and second switches around the input voltage.
    Type: Application
    Filed: April 30, 2001
    Publication date: March 21, 2002
    Applicant: Delta Electronics, Inc.
    Inventors: Guisong Huang, Yilei Gu, Zhizheng Liu, Alpha J. Zhang
  • Patent number: 6349044
    Abstract: A three-level DC-to-DC converter is provided having zero-voltage and zero-current switching (ZVZCS). A flying capacitor is provided on the primary side of the converter to achieve zero voltage switching (ZVS). In addition, during freewheeling (i.e., when no power is being transferred from the primary side to the secondary side), an auxiliary power source is provided to eliminate the circulating energy and to achieve zero current switching (ZCS) for the commutation switches.
    Type: Grant
    Filed: September 8, 2000
    Date of Patent: February 19, 2002
    Assignee: Virginia Tech Intellectual Properties, Inc.
    Inventors: Francisco Canales-Abarca, Peter M. Barbosa, Fred C. Lee
  • Patent number: 6324081
    Abstract: A switching power source apparatus reduces power loss and improves conversion efficiency of a switching power source part by rectifying and smoothing a commercially available alternating power source supplied to an oscillation drive circuit and a switching circuit part that constitutes a half-bridge circuit. An output of the half-bridge circuit is grounded via a resonance capacitor, a choke coil, and a primary winding of an insulated type converter transformer. This converter transformer has a secondary winding for obtaining a +B voltage and high-voltage windings for obtaining a high-level output voltage. Further, fluctuation in the voltage of the high-level output voltage is supplied to the oscillation drive circuit via resistors, a control circuit, and a photo-coupler, whereby the switching circuit part is controlled.
    Type: Grant
    Filed: October 20, 2000
    Date of Patent: November 27, 2001
    Assignee: Sony Corporation
    Inventors: Hiroshi Sakamoto, Kenji Iwai
  • Patent number: 6323707
    Abstract: A pulse signal output circuit charges and discharges a capacitor in response to a clock signal and outputs a pulse signal having a pulse width determined by a time for charging and discharging the capacitor. A control signal generation circuit outputs a control signal in response to the pulse signal, where the control signal has a first voltage level determined by the pulse width. An output circuit has a first output transistor and a first regulating transistor connected in series between the first power supply node and the output terminal. The first output transistor is operated in response to a signal transferred from inside or outside a semiconductor device, and the first regulating transistor is operated in response to the control signal.
    Type: Grant
    Filed: January 28, 2000
    Date of Patent: November 27, 2001
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Kenji Arai
  • Patent number: 6324080
    Abstract: A conversion apparatus having transistors, comprising means for inverting a DC voltage in order to obtain an AC voltage, means for filtering the AC voltage, including at least one parallel inductor Lp, the device being capable of operating above a resonant frequency Fp. The conversion apparatus comprises means for predicting a zero crossing of the instantaneous current I1p in the parallel inductor Lp, and means for causing a transistor of the device to switch if a zero crossing of the current I1p is predicted.
    Type: Grant
    Filed: September 8, 1998
    Date of Patent: November 27, 2001
    Assignee: GE Medical Systems, S.A.
    Inventor: Jacques Laeuffer
  • Patent number: 6317347
    Abstract: An inverter circuit for supplying power to a lamp. The circuit comprises a DC voltage supply source. The circuit also comprises a transformer having a primary and a secondary winding. The secondary winding is coupled to the lamp and the primary winding is coupled to the DC supply source. The circuit also comprises a pair of inductors coupled in series to opposite ends of the primary winding. A capacitor couples the inductors together. The circuit is configured such that the pair of inductors, in conjunction with the capacitor, alternately resonate to provide an AC current supply source to the lamp. The circuit further comprises a pair of switches which alternately turn “on” and “off”, thereby causing the pair of inductors to alternately resonate. A control driver is coupled to the pair of switches and is configured to alternately turn on and off the pair of switches. Advantageously, the control driver comprises a PWM control driver.
    Type: Grant
    Filed: October 6, 2000
    Date of Patent: November 13, 2001
    Assignee: Philips Electronics North America Corporation
    Inventor: Da Feng Weng
  • Patent number: 6317338
    Abstract: Inductive power transfer across an extended gap (100) from a primary conductor (119) is provided by means of a resonant intermediate loop comprised of capacitor (118) with inductor (117) carrying a larger resonating current, that can in turn generate an inductive field to be collected by a pickup coil (120). This process and device find application in an electroluminescent advertising panel.
    Type: Grant
    Filed: November 8, 1999
    Date of Patent: November 13, 2001
    Assignee: Auckland Uniservices Limited
    Inventor: John Talbot Boys
  • Patent number: 6314006
    Abstract: In a DC/DC converter for producing a DC voltage from a supplied DC voltage with a reversible direction of action, a transformer operating in push-pull on the primary and secondary sides, the respective center taps are connected to a first terminal for the respective DC voltage, and further winding terminals are each connected via a semiconductor switch to a second terminal for the respective DC voltage, the semiconductor switches being controlled synchronously in pairs.
    Type: Grant
    Filed: August 29, 2000
    Date of Patent: November 6, 2001
    Assignee: Mannesmann VDO AG
    Inventors: Reinhold Berberich, Andreas Fürbeth
  • Publication number: 20010026459
    Abstract: A transformer having a coil winding structure for transforming a voltage which is inputted through a primary coil section and for outputting a transformed voltage toward a secondary coil section. In the transformer, the primary coil section includes a plurality of sub-coil sections which are connected in parallel, and a plurality of terminals are connected to the plurality of sub-coil sections, respectively, in a manner such that corresponding portions of the sub-coil sections have the same current direction.
    Type: Application
    Filed: January 2, 2001
    Publication date: October 4, 2001
    Inventors: Yong-woon Han, Seong-deog Jang, Kwang-seok Kang, Dae-sung Han, Jin-ho Kim, Han-seong Yoo, Han-sung Kang
  • Patent number: 6292377
    Abstract: The switching converters of a power supply device are adapted to equally share the power output of the device. The power supply device 1 comprises a plurality of resonance type switching converters 4, 5 connected in parallel relative to a load, frequency control circuits 6, 7 for controlling respectively the switching frequencies of the switching converters 4, 5, a feedback circuit 8 for feeding back the voltage applied to the load and a resonance current balance circuit 9 for detecting the wave heights of the resonance currents flowing respectively through the switching converters 4, 5 and comparing them. The frequency control circuits 6, 7 control the switching frequencies so as to make the voltage applied to the load show a predetermined voltage value and also make the wave heights of the resonance currents equal to each other.
    Type: Grant
    Filed: June 20, 2000
    Date of Patent: September 18, 2001
    Assignee: Sony Corporation
    Inventor: Masayoshi Sasaki
  • Patent number: 6288913
    Abstract: A power supply for achieving high output power levels at a high efficiency from a compact profile. The power supply includes a current regulator which receives a source voltage and outputs a signal having a constant current. The signal output from the regulator is provided to a center tap of a primary winding of a transformer. The ends of the primary winding of the transformer are connected to switches which are controlled by a switch driver. The transformer, switches and switch driver form a resonant oscillator. The switch driver is connected to a zero voltage level detector which detects when the voltage of the signal output from the current regulator reaches a zero level. When such a detection is made, the zero voltage level detector provides an enable signal to the switch driver to operate the switches in a push-pull mode. By operating the switches in a push-pull mode, the energy balance and resonance of the transformer can be maintained.
    Type: Grant
    Filed: April 27, 2000
    Date of Patent: September 11, 2001
    Assignee: Rantec Power Systems Inc.
    Inventor: Robert K. White
  • Patent number: 6272026
    Abstract: A pseudo-push-pull DC:DC converter topology replaces one primary switching transistor with a high speed passively switched diode coupled between one end of a transformer first primary winding and ground. A second primary winding is coupled to ground via a solid state switch that is driven with a control circuit that outputs a single drive signal of slightly less than 50% duty cycle. The other ends of the first and the second transformer primaries are coupleable to a source of Vin. The topology includes a gapped transformer whose transformer core stores sufficient electromagnetic energy when the solid state switch is turned-on by the control circuit to drive a load coupled to the transformer secondary when the solid state switch is turned-off. When the solid state switch is turned-off by the control circuit, the diode self-biases on, coupling the first transformer primary winding between Vin and ground, as though a perfectly driven solid state switch were turned-on.
    Type: Grant
    Filed: September 26, 2000
    Date of Patent: August 7, 2001
    Assignee: Swtich Power, Inc.
    Inventors: Dimitry Goder, Anatoly Shteynberg
  • Patent number: 6272027
    Abstract: An AC active clamp, a method of operating the same and a power factor corrector employing the AC active clamp or the method. The power factor corrector has a primary switching circuit coupled to a primary winding of an isolation transformer and a rectifier coupled to a secondary winding of the isolation transformer. The primary switching circuit has first and second power switches configured to receive unrectified AC power. In one embodiment, the AC active clamp includes a switching circuit having first and second clamping switches series coupled in opposition and a capacitor coupled to the switching circuit. The switching circuit and the capacitor are coupled across at least a portion of the primary winding and are configured to mitigate adverse effects of a reverse recovery phenomenon associated with the rectifier and to effect substantially zero voltage switching of the first and second power switches of the primary switching circuit.
    Type: Grant
    Filed: July 28, 2000
    Date of Patent: August 7, 2001
    Inventors: Simon Fraidlin, Anatoliy Polikarpov
  • Patent number: 6268587
    Abstract: In an electric arc welder including a main transformer with a primary stage coupled to a secondary stage in which is created an AC output current, a first switch opened and closed at a given rate to pass a series of first pulses of DC current in a first circuit having a first lead and through at least a portion of the primary stage in a first electrical direction, with each of the first pulses having a length determined by the time the first switch is closed, a second switch opened and closed at the given rate to pass a series of second pulses of DC current in a second circuit having a second lead through at a least a portion of the primary stage in a second electrical direction with each of the second pulses having a length determined by the time the second switch is closed, and a control circuit for rapidly closing the first and second switches in sequence to induce an AC current in the output stage, the improvement comprising: a first current transformer surrounding the first lead of the first circuit to d
    Type: Grant
    Filed: February 22, 2000
    Date of Patent: July 31, 2001
    Assignee: Lincoln Global, Inc.
    Inventors: Todd Eric Kooken, Lifeng Luo
  • Patent number: 6266255
    Abstract: A power supply apparatus is disclosed, that comprises a DC power supply, a plurality of switch means for converting the output voltage of the DC power supply into an AC voltage, a transformer tap-connected to the DC power supply, a capacitor for charging/discharging an output current of the DC power supply, and a choke coil for suppressing the fluctuation of the output current of the DC power supply or the fluctuation of the current value of a discharge current of the capacitor.
    Type: Grant
    Filed: June 12, 2000
    Date of Patent: July 24, 2001
    Assignee: NEC Corporation
    Inventor: Junichi Kobayashi
  • Patent number: 6259615
    Abstract: A CCFL power converter circuit is provided using a high-efficiency zero-voltage-switching technique that eliminates switching losses associated with the power MOSFETs. An optimal sweeping-frequency technique is used in the CCFL ignition by accounting for the parasitic capacitance in the resonant tank circuit. Additionally, the circuit is self-learning and is adapted to determine the optimum operating frequency for the circuit with a given load. An over-voltage protection circuit can also be provided to ensure that the circuit components are protected in the case of open-lamp condition.
    Type: Grant
    Filed: November 9, 1999
    Date of Patent: July 10, 2001
    Assignee: O2 Micro International Limited
    Inventor: Yung-Lin Lin
  • Patent number: 6246593
    Abstract: The use of synchronous rectifier MOSFETs in the secondary circuit of AC/DC converters is made possible in synchronous rectifier unfriendly topologies such as flyback converters by sensing the onset of forward current in the MOSFET drain-source circuit, optionally converting that current information into logic level signals, and using the information or signals to drive the gate of the synchronous rectifier MOSFET.
    Type: Grant
    Filed: May 6, 1999
    Date of Patent: June 12, 2001
    Assignee: Astec International Limited
    Inventor: Wing Ling Cheng
  • Patent number: 6236579
    Abstract: In a power supply apparatus which supplies a high-tension alternating voltage to a load, field-effect transistors (N-MOS) are disposed between both ends of a converter transformer having a center tap and the ground respectively, and a field-effect transistor (P-MOS) is disposed between the center tap and a power supply. In an ordinary operation, a transistor connected to the center tap is being on and transistors at the both ends of the converter transformer are alternately switched at the same frequency by a converter transformer driving circuit, thereby generating the high-tension alternating voltage on the side of a secondary winding of the converter transformer. When the generation of the high-tension alternating voltage is stopped, the driving circuit is controlled to cause the transistor connected to the center tap to be off and cause the transistors at the both ends of the converter transformer to be on, thereby preventing an unstable output voltage generated when output oscillation is stopped.
    Type: Grant
    Filed: July 3, 2000
    Date of Patent: May 22, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Michiko Watanabe, Hajime Motoyama
  • Patent number: 6218891
    Abstract: An integrated circuit including a metal-semiconductor field-effect transistor (MESFET) having a nominal intrinsic capacitance and requiring a negative voltage to bias the MESFET into a non-conduction state, a method of driving the MESFET and a power converter employing the integrated circuit and method. In one embodiment, the integrated circuit includes a driver including a bias capacitor integrated with the MESFET. The driver is configured to apply a positive voltage to bias the MESFET into a conduction state, and apply the negative voltage to bias the MESFET into the non-conduction state without employing an external negative bias source.
    Type: Grant
    Filed: July 28, 2000
    Date of Patent: April 17, 2001
    Assignee: Lucent Technologies Inc.
    Inventors: Ashraf W. Lotfi, Allen F. Rozman, Jian Tan, Wei Tang
  • Patent number: 6205043
    Abstract: A power supply for a quadrupole mass spectrometer which operates using an RF signal. The RF signal is controllable via a feedback loop. The feedback loop is from the output, through a comparator, and compared to a digital signal. An air core transformer is used to minimize the weight. The air core transformer is driven via two out of phase sawtooth signals which drive opposite ends of the transformer.
    Type: Grant
    Filed: September 8, 1999
    Date of Patent: March 20, 2001
    Assignee: California Institute of Technology
    Inventors: Ara Chutjian, Dean Aalami, Murray Darrach, Otto Orient
  • Patent number: 6191960
    Abstract: A secondary active clamp for a power converter, a method of actively clamping energy of the power converter and a power converter employing the clamp or the method. The power converter has a primary switching circuit coupled to a primary winding of an isolation transformer and a rectifier coupled to a secondary winding of the isolation transformer. In one embodiment, the clamp includes (1) an inductor coupled in series with a freewheeling diode of the rectifier and (2) a series-coupled capacitor and clamping switch coupled in parallel with the inductor. The series-coupled capacitor and clamping switch cooperate with the inductor to mitigate adverse effects of a reverse recovery phenomenon associated with the rectifier and to effect substantially zero voltage switching of a power switch of the primary switching circuit.
    Type: Grant
    Filed: May 9, 2000
    Date of Patent: February 20, 2001
    Assignee: Lucent Technologies Inc.
    Inventors: Simon Fraidlin, Anatoliy Polikarpov
  • Patent number: 6184649
    Abstract: A power converter supplies a charging current to a rechargeable battery responsive to a control module. The control module includes a microcontroller, a memory coupled to the microcontroller and power converter code. The power converter code causes the microcontroller to determine a battery output voltage of the rechargeable battery. The power converter code also causes the microcontroller to provide a control signal, which adjusts the power converter output voltage responsive to the battery output voltage. The control module also provides for a desulfation mode when the power converter is in a storage mode.
    Type: Grant
    Filed: July 9, 1999
    Date of Patent: February 6, 2001
    Assignee: Progressive Dynamics, Inc.
    Inventor: Thomas H. Phlipot
  • Patent number: 6181576
    Abstract: A rectifier 4 develops a rectified voltage between output terminals thereof. Capacitors 6a and 6b are connected in series between the output terminals of the rectifier. Inverters 8a and 8b convert DC voltages across the associated ones of the capacitors 6a and 6b into high-frequency voltages, which are, then, voltage transformed. The transformed voltages are rectified by diodes 24a and 24b for application to an arc-utilizing apparatus. Inverter control circuits 38a and 38b control the inverters 8a and 8b, respectively, in such a manner as to make current-representative signals from current detectors 50a and 50b equal to a reference signal, respectively. A voltage divider 54 is connected in parallel with the series combination of the capacitors 6a and 6b. Voltage detectors 62a and 62b connected between the junction A of the capacitors 6a and 6b and the junction B of resistors of the voltage-divider 54 develop a voltage representative signal representative of the voltage between the junctions A and B.
    Type: Grant
    Filed: April 7, 2000
    Date of Patent: January 30, 2001
    Assignee: Sansha Electric Manufacturing Company Limited
    Inventors: Tetsuro Ikeda, Kenzo Danjo, Takamitsu Imahori
  • Patent number: 6166922
    Abstract: A current detecting circuit detects amplitude of a current flowing toward the connecting point of a first transistor and a serial circuit through a second transistor and a comparing circuit compares amplitude of the current detected by the current detecting circuit with the reference value. An oscillation control circuit controls a control current supplied to an oscillating circuit in order to raise the oscillation frequency of the oscillating circuit when amplitude of the current detected by the current detecting circuit is smaller than the reference value as a result of comparison by the comparing circuit in view of preventing the oscillation frequency to be further lowered. Therefore, it is no longer required to design the apparatus by giving allowance to take into consideration the temperature characteristics and fluctuation of parts unlike the related art in which the minimum oscillation frequency of the oscillating circuit is set. Accordingly, variable range of the oscillation frequency can be expanded.
    Type: Grant
    Filed: October 25, 1999
    Date of Patent: December 26, 2000
    Assignee: Sony Corporation
    Inventors: Makoto Kobori, Susumu Kaneko
  • Patent number: 6166927
    Abstract: A push-pull converter for converting an input voltage to a selectable output voltage is disclosed. The push-pull converter includes a pair of primary switches and a pair of primary windings of a transformer. The voltage stress across the primary switches is regulated by means of a clamp capacitor. The clamp capacitor clamps the voltage of the primary switches during the reset of the primary windings of the transformer. An alternate embodiment is also disclosed in which the voltage stress across the primary switches is regulated by means of two clamp capacitors. The clamp capacitor clamps the voltage of the primary switches during the reset of the primary windings of the transformer. The clamp capacitors extend the transformer reset period to include the lagging dead time for the corresponding switches, as well as the complementary powering stage. Current in the output section during the dead times is permitted by means of an additional diode, therein.
    Type: Grant
    Filed: July 23, 1999
    Date of Patent: December 26, 2000
    Assignee: Ericsson Inc.
    Inventors: Richard W. Farrington, William Hart
  • Patent number: 6166932
    Abstract: A DC-to-AC converting circuit generates an alternating current by alternately switching a set of switching elements. The alternating current is supplied to a load Lo via an output filtering circuit. If a current detection resistor R1 in the DC-to-AC converting circuit detects an output current that exceeds a reference voltage Vref corresponding to an over-current set value, certain switching elements are turned off to disconnect the DC-to-AC converting circuit from the power source. However, the DC-to-AC converting circuit continues to generate an alternating current from energy stored in one or more inductors that are coupled to the DC-to-AC converting circuit. Preferably, a closing circuit is formed from a diode, a switching element, the load Lo and the inductors. Thus, even if the DC-to-AC converting circuit is disconnected from its power source, an alternating current continuously flows to the load Lo.
    Type: Grant
    Filed: July 20, 1999
    Date of Patent: December 26, 2000
    Assignee: Kabushiki Kaisha Toyoda Jidoshokki Seisakusho
    Inventor: Kota Otoshi
  • Patent number: 6151226
    Abstract: A four quadrant power conversion topology comprising a multi-winding inductor, four switches, and four diodes is disclosed. The four quadrant power conversion is utilized in a number of power conversion devices such as a power efficient non-linear power amplifier that comprises the 4Q power conversion topology of the present invention and a switch-control-signal generator coupled to the 4Q power conversion topology. The switch-control-signal generator generates switch activation signals for driving the four switches of the 4Q power conversion topology.
    Type: Grant
    Filed: May 5, 1999
    Date of Patent: November 21, 2000
    Assignee: Marconi Communications, Inc.
    Inventors: William I. H. Chen, Edwin Glenn Yancey, Mahlon Danny Kimbrough
  • Patent number: 6141225
    Abstract: A DC/DC converter comprising a buck stage that includes a buck switch, a push-pull stage that includes push-pull switches, and a controller to control the switching phases of the buck and push-pull switches. The turn-on phases of these buck and push-pull switches are automatically and continuously adjusted to an optimal value at each occurrence of a synchronization pulse produced at a fixed frequency by an autosynchronization circuit.
    Type: Grant
    Filed: March 17, 1999
    Date of Patent: October 31, 2000
    Assignee: Alcatel
    Inventors: Michel Gak, Giorgio Trusgnach
  • Patent number: 6137698
    Abstract: A switching power supply has a secondary rectifying circuit including two MOS transistors which can operate in a third quadrant for use as low-loss rectifying devices. While the MOS transistors are operating in the third quadrant, the application of a gate voltage to the MOS transistors is forcibly stopped to turn off the MOS transistors. Periods in which the MOS transistors operate in the third quadrant are prevented from overlapping each other. The periods in which the MOS transistors operate in the third quadrant may be established by an ON timer, and the periods in which the MOS transistors remain de-energized may be established by an OFF timer.
    Type: Grant
    Filed: September 29, 1998
    Date of Patent: October 24, 2000
    Assignee: Shindengen Electric Manufacturing Co., Ltd.
    Inventors: Tadashi Yukawa, Nobuhiro Tada
  • Patent number: 6115267
    Abstract: A transformer isolated, Power Factor Corrected (PFC) AC-DC power converter comprises a main power path which is buck derived, and most of the power passes through a single power stage to the output. A parallel path in the secondary circuit shunts current to a storage capacitor during the times when the input AC current is at its peak, and returns current to the circuit when the input AC current is low. In one embodiment, the shunt stage comprises a secondary side boost converter. In another, the shunt stage comprises a buck converter. Regardless, the input stage may operate without input rectifiers if AC switches, such as back to back MOSFET's are used, because the output of the transformer and secondary rectifiers is the same regardless of the polarity of the instantaneous input voltage.
    Type: Grant
    Filed: June 8, 1999
    Date of Patent: September 5, 2000
    Inventor: Edward Herbert
  • Patent number: 6094014
    Abstract: A circuit arrangement for operating a semiconductor light source, includes input terminals for connecting a supply voltage, an input filter, a converter having a control circuit, and output terminals for connecting the semiconductor light source. The circuit arrangement is provided with a voltage detector for detecting the output voltage at the output terminals.
    Type: Grant
    Filed: August 3, 1998
    Date of Patent: July 25, 2000
    Assignee: U.S. Philips Corporation
    Inventors: Marcel J. M. Bucks, Engbert B. G. Nijhof
  • Patent number: 6055162
    Abstract: A DC-DC voltage converter 40, which is adaptable to VHF operation, has a power oscillator 52 to which a filtered input DC voltage 50 is applied for conversion to an output DC voltage. The power oscillator includes a push-pull amplifier 58, 60 and an impedance transformation circuit 62 to which the amplifier is connected. The power oscillator also includes a rectifier circuit 64 which is connected to the impedance transformation circuit. A feedback circuit 68 controls the frequency of the oscillator to regulate the output DC voltage. The oscillator frequency depends on the impedance values of oscillator circuit components and the values of a plurality of oscillator component intrinsic parameters.
    Type: Grant
    Filed: March 12, 1998
    Date of Patent: April 25, 2000
    Assignee: Northrop Grumman Corporation
    Inventors: Albert G. Tarrillo, Dennis Schaefer, Scott K. Suko, Edward L. Rich, III, Keith L. Rowe
  • Patent number: 6043993
    Abstract: In a switching power source, by alternately turning on first and second MOS transistors, a switching current flows to a primary winding of a transformer, and an alternate current is transferred to a secondary side. The alternate voltage caused in a secondary winding is full-wave rectified by first and second diodes. Resonance elements (capacitor and coil) are connected to a tertiary winding coupled to an isolation transfer, thereby enabling the primary side to be set into a resonated state and to be set to a current resonance type switching power source. Since a leakage inductance of the transformer is not set to a resonance element, an interval between the windings of the isolation transformer can be closely coupled. Since a resonance current is not directly turned on/off, a peak value of the primary current is decreased and switching loss and loss due to an on-resistance can be decreased. The efficiency of a current resonance type switching power source is thus improved.
    Type: Grant
    Filed: April 1, 1999
    Date of Patent: March 28, 2000
    Assignee: Sony Corporation
    Inventors: Katsumi Kobori, Noritoshi Imamura
  • Patent number: 6018467
    Abstract: A resonant mode power supply includes a D.C. voltage source and switching elements for alternatively connecting an oscillating circuit, including a primary winding of a transformer, to the D.C. voltage source and to ground. A first secondary winding supplies the main output voltage of the power supply and a second secondary winding provides a control output voltage. An opto-coupler is included and has a light emitter connected to the second secondary winding, and a light sensor connected to a controller for controlling the switching of the switching elements, wherein the higher the frequency of the switching, the lower the power being supplied by the power supply. Burst mode stand-by is started by the first secondary winding being shunted to the second secondary winding causing the light emitter to emit a maximum amount of light. The controller increases the switching frequency until it exceeds a predetermined maximum frequency.
    Type: Grant
    Filed: July 28, 1999
    Date of Patent: January 25, 2000
    Assignee: Philips Electronics North America Corporation
    Inventors: Naveed Majid, Jerzy Janczak, Patrick E. G. Smeets
  • Patent number: 6011702
    Abstract: Low noise DC/DC switching power supply employs a transformer, a main switch and an auxiliary switch. The auxiliary switch merely reflects the switching of the main switch and has lower voltage ratings. A maximum noise suppression is accomplished when both switches have the same current ratings. The power supply takes advantage of some resonant properties but operates in forward and/or flyback square wave modes. When the main switch is turned off, a leakage energy stored in the transformer is delivered to a capacitor. Subsequently, both switches are turned on, wherein the capacitor voltage is applied across the primary winding of the transformer. When the capacitor voltage is reduced to a desired value, the auxiliary switch turns off, wherein the primary voltage is reduced to the input voltage. The difference between both primary voltages is thus regulated. The EMI/RFI performance of the power supply is dramatically improved. A discontinuous mode allows uninterrupted input current at any time.
    Type: Grant
    Filed: March 31, 1998
    Date of Patent: January 4, 2000
    Inventor: Jeff Gucyski
  • Patent number: 5982643
    Abstract: A system to control the output voltage of a power converter in response to a specific load battery condition. The system contains a power converter, a TCMS interface attached thereto and a controller for selectively and/or adaptably changing the magnitude of converter output voltage. A control module is incorporated in the system to automatically change converter output voltage up or down in response to the load (input) voltage. The module contains a microcontroller to sense the battery (input) voltage process said input voltage with an analog-to-digital converter. The microcontroller is programmed to execute a series of routines to determine the proper charging voltage for the system. Thereafter, the control module communicates this information through the interface of the power converter to cause the power converter to charge at the optimum voltage. In the alternative, a plug-in component containing passive circuitry may be used to manually signal the power converter to charge at a predetermined voltage.
    Type: Grant
    Filed: October 10, 1996
    Date of Patent: November 9, 1999
    Assignee: Progressive Dynamics, Inc.
    Inventor: Thomas H. Phlipot
  • Patent number: 5969955
    Abstract: A forward converter useful in a power supply utilizing an isolation transformer includes a crowbar circuit and control such that turn-off by discharging an output capacitor is made advantageously faster than conventional circuits. The forward converter has a push-pull arrangement of two switching devices. For operation in the output voltage-on mode, the forward converter transfers energy in a peak forward converter mode with the first switching device being turned on and off. For output voltage turn-off, the crowbar circuit is activated by turning on the second switching device which results in a reverse voltage at the secondary winding of the isolation transformer. The reverse voltage is superimposed on the converter output voltage, the sum of the converter output voltage and the reverse voltage being imposed across the crowbar circuit.
    Type: Grant
    Filed: December 29, 1998
    Date of Patent: October 19, 1999
    Assignee: General Electric Company
    Inventors: Laszlo Laskai, Milan Zarko Ilic
  • Patent number: 5965989
    Abstract: A circuit that senses a current signal in a secondary winding of a transformer by monitoring a current signal in a primary winding of the transformer. The monitored current signal contains an effective current component and a magnetization current component. The magnitude of the effective current signal is related to the magnitude of the current signal in the secondary winding by the turns ratio of the transformer. The magnetization current signal produces flux in the transformer core and does not contribute to producing current in the secondary winding of the transformer. In addition, the magnetization current is 90 degrees out of phase with the effective current signal in the primary winding. The effective current signal in the primary winding is in phase with the voltage signal applied to the primary winding. The invention integrates the monitored current signal over 0 degrees to 180 degrees of the effective current signal waveform.
    Type: Grant
    Filed: July 30, 1996
    Date of Patent: October 12, 1999
    Assignee: Micro Linear Corporation
    Inventor: Urs H. Mader
  • Patent number: 5959438
    Abstract: A boost converter employs an isolated active snubber to reduce the losses caused by the reverse-recovery characteristic of a boost rectifier and the turn-on discharge loss of the output capacitance of the boost switch. The losses are reduced by inserting the primary winding of a coupled-inductor in the series path of the boost switch and the rectifier, to control the rate of current change (i.e., the di/dt rate) of the rectifier during its turn-off, and to create the conditions for zero-voltage turn-on for the boost switch. The energy from the inductor, after the boost-switch is turned off, is delivered to the output via the secondary winding of the coupled-inductor which is connected in series with a clamping capacitor and an auxiliary switch to form an isolated active snubber. The same technique can be extended to any member of the PWM-converter family.
    Type: Grant
    Filed: January 9, 1998
    Date of Patent: September 28, 1999
    Assignee: Delta Electronics, Inc.
    Inventors: Milan M. Jovanovic, Yungtaek Jang
  • Patent number: 5933335
    Abstract: A line type modulator for modulating an RF power device in a medical linear accelerator is described. The modulator employs a low voltage DC power source and a flyback transformer. Current sensing circuitry senses current in the primary winding of the flyback transformer and generates a current sense signal indicative thereof. A solid-state switching stage is coupled between the DC power source and the flyback transformer which electrically connects and disconnects the DC power source and the primary winding in response to a control signal. Control circuitry coupled to the current sensing circuitry and the switching stage generates the control signal in response to the current sense signal. The anode of a charge diode assembly is coupled to the secondary winding of the flyback transformer. A delay element is coupled to the cathode of the charge diode assembly. A pulse forming network is coupled to the delay element and generates an energy pulse.
    Type: Grant
    Filed: January 15, 1998
    Date of Patent: August 3, 1999
    Assignee: Siemens Medical Systems, Inc.
    Inventors: Roger N. Hitchcock, Michael J. Marziale, Lance W. Thompson
  • Patent number: 5917711
    Abstract: DC power supply apparatus includes an input-side rectifier for converting an AC signal from an AC power supply into a DC signal. A DC-to-high-frequency converter converts the DC signal into a high frequency signal in response to a control signal from a control unit. An output-side rectifier converts the high frequency signal into a DC signal and applies it to a load. An input current detector detects an input current flowing through the input-side rectifier and generates a signal representative of the input current. A load current detector detects a load current flowing through the load and generates a signal representative of the load current.
    Type: Grant
    Filed: November 24, 1998
    Date of Patent: June 29, 1999
    Assignee: Sansha Electric Manufacturing Company, Limited
    Inventors: Kunio Shikata, Haruo Moriguchi, Tetsuro Ikeda, Kenzo Danjo, Takeshi Omura, Hideo Ishii
  • Patent number: 5907481
    Abstract: A D.C.--D.C. down converter utilizes a controlled converter primary switching circuit and a full-wave rectified secondary circuit employing synchronous rectification. An isolation transformer having split first and second secondary windings supplies current to the full-wave secondary circuit. The gating signals for synchronous rectification are produced by a switch conduction control including a secondary switch control receiving control signals from the primary switch control through a control current isolating transformer. The secondary switch control is powered by the secondary converter circuit. Through the use of a split secondary winding of the isolation transformer and a full-wave rectifying circuit, the secondary converter circuit of the D.C.--D.C. converter may readily generate drive voltages for supply to the secondary switch control, allowing the secondary converter circuit and load to be fully isolated from the primary converter circuit and input source.
    Type: Grant
    Filed: October 31, 1997
    Date of Patent: May 25, 1999
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventor: Claes Svardsjo
  • Patent number: 5903448
    Abstract: A four quadrant flyback converter, employable as part of a ringing signal generator, includes: (1) a transformer having first and second primary windings of opposite polarity and a secondary winding, (2) first and second switches that alternatively couple the first and second windings, respectively, to a source of DC input power and (3) a bidirectional switch coupling the secondary winding to an output of the converter, the first, second and bidirectional switches switchable to provide a continuous waveform at the output.
    Type: Grant
    Filed: August 20, 1997
    Date of Patent: May 11, 1999
    Assignee: Lucent Technologies Inc.
    Inventor: Marco Antonio Davila, Jr.