Single-ended, Separately-driven Type Patents (Class 363/20)
  • Patent number: 5086381
    Abstract: A DC-DC converter includes a transformer and a switching element. The primary winding of the transformer and the switching element are connecting in series with a DC power source. A DC output is extracted via a rectifier circuit connected to a secondary winding of the transformer. A capacitor is connected in parallel to the switching element, and a saturable reactor is connected between the secondary winding of the transformer and the rectifier.
    Type: Grant
    Filed: October 9, 1990
    Date of Patent: February 4, 1992
    Assignees: Toko Kabushiki Kaisha, Nemic Lambda Kabushiki Kaisha, Yutaka Electric Mfg. Co., Ltd., Densetsu Corp.
    Inventors: Shigeru Kameyama, Koji Arakawa, Kazushi Watanabe, Hitoshi Yoshioka, Isami Norigoe
  • Patent number: 5072353
    Abstract: A circuit configuration for a blocking oscillator converter switching power supply includes a switch. A transformer has a primary winding in the circuit of a direct voltage source being connected in series with the switch, and a secondary winding to be connected to a load. The transformer is magnetized in a first operating phase in which the switch is switched on and current flows in the primary winding, and is demagnetized in a second operating phase in which the switch is switched off and current flows in the secondary winding. An integratable control circuit has a demagnetization monitor detecting a voltage at a transformer winding and preventing the switched-off switch for being switched on until the feedback voltage in the blocking phase has exceeded a predetermined threshold value, and a suppression circuit blocking the turn-on enablement for the switch during a predetermined time after the beginning of the blocking phase.
    Type: Grant
    Filed: October 1, 1990
    Date of Patent: December 10, 1991
    Assignee: Siemens Aktiengesellschaft
    Inventor: Martin Feldtkeller
  • Patent number: 5066900
    Abstract: A two switch, DC/DC converter provides sufficient inductive energy storage at the termination of the "on" period of each switch to alter the charge on the intrinsic and stray capacitance of the combination of switches producing zero voltage across the alternate switch prior to its turn on. A short dead-band between the turn on pulses provided by the control circuit allows time for this transition. Thus the energy stored in the capacitance of the switches is returned to the source and load rather than being dissipated in the switching devices. This greatly improves the efficiency of the converter particularly when operating at high frequency. The unique topology of the converter provides other new and useful characteristics in addition to zero voltage switching capability such as operation as constant frequency with pulse-width-modulation for regulation, quasi-square wave output current, and the ability to integrate the magnetic elements with or without coupling.
    Type: Grant
    Filed: June 22, 1990
    Date of Patent: November 19, 1991
    Assignee: Computer Products, Inc.
    Inventor: John A. Bassett
  • Patent number: 5060128
    Abstract: A flyback power supply for use with a cathode-ray tube includes a flyback transformer which comprises a core having two spaced core legs, and two core units supported respectively on the core legs. Each of the coil units includes a low-voltage coil bobbin fitted over one of the core legs, a low-voltage coil wound around the low voltage coil bobbin, a high-voltage coil bobbin disposed around the low-voltage coil bobbin, and a high-voltage coil which comprises a plurality of coil layers wound successively around the high-voltage coil bobbin with insulating layers interposed between the coil layers, the low-voltage coils of the coil units being connected parallel to each other. Diodes are connected in series with the coil layers, respectively of the high-voltage coil of each of the coil units such that voltages produced across the coil layers will be in phase with each other.
    Type: Grant
    Filed: March 30, 1990
    Date of Patent: October 22, 1991
    Assignee: Victor Company of Japan, Ltd.
    Inventors: Shunji Onodera, Shinichi Ito
  • Patent number: 5057986
    Abstract: A single-ended DC-to-DC power converter which is operative at very high switching frequencies with zero-voltage resonant transition switching. A single magnetic element functions as both a storage inductor and a transformer. A charging capacitor is switched to induce a reversal current through the inductor for providing the zero-voltage switching function. Control to output characteristics are identical to those of conventional buck and buck-boost converters. The invention provides efficient, high-frequency operation and isolation of the output from the input power source with minimal component volume. The control system is adaptable to constant frequency pulse width modulation for voltage regulation.
    Type: Grant
    Filed: March 12, 1990
    Date of Patent: October 15, 1991
    Assignee: Unisys Corporation
    Inventors: Christopher P. Henze, David S. Lo, Hubert C. Martin, Jr.
  • Patent number: 5043598
    Abstract: A high voltage generating circuit which includes a switching circuit for switching a DC input, a fly-back transformer whose input coil is driven by pulses delivered from the switching actuation of the switching actuation of the circuit, a rectifier circuit for rectifying the fly-back voltage generated in the output coil of the fly-back transformer, a capacitor for smoothing the rectified output, and a voltage stabilizing circuit. A diode is electrically connected to one terminal of the output coil of the fly-back transformer on the low-voltage side thereof as compared with the ground, the diode being so determined as to position in the forward direction to the direction of rectification. The voltage stabilizing circuit is formed by a voltage sensing circuit for sensing a DC high voltage output, comparing it with a reference voltage applied from a reference voltage source and generating an output of a result of comparison and a control circuit connected between the anode of the diode and the ground terminal.
    Type: Grant
    Filed: September 15, 1989
    Date of Patent: August 27, 1991
    Assignee: TDK Corporation
    Inventors: Tsutomu Maeda, Kiyoshi Matsui, Michio Ishikawa, Takayuki Kanno, Yasushi Iwata
  • Patent number: 5038263
    Abstract: An improvement is provided for a circuit having a first winding of N.sub.1 turns connected in series with a total inductance of L across a first voltage V.sub.1 and a second steering winding of N.sub.2 turns connected in series with a total inductance L.sub.2 across a second voltage V.sub.2 with the second winding magnetically coupled to the first winding and the first winding having an inductance L.sub.c produced by the N.sub.1 turns as seen across the first winding comprising L.sub.1 set substantially greater to zero and L.sub.2 set substantially equal to (L.sub.c) (N.sub.2 /N.sub.1).sup.2 ((V.sub.2 /V.sub.1) (N.sub.1 /N.sub.2)-1)). The setting of L.sub.1 and the setting of L.sub.2 providing an improvement to reduce ac ripple current.
    Type: Grant
    Filed: January 3, 1990
    Date of Patent: August 6, 1991
    Assignee: EG&G Power Systems, Inc.
    Inventors: Joseph Marrero, Christopher Peng
  • Patent number: 5008795
    Abstract: A DC-to-DC power converter topology utilizing parallel connected transformers in a buck switching configuration with each stage operated 180.degree. out-of-phase, with the primary windings of the transformers sequentially feeding into a common filter capacitor. On each transformer, a secondary winding is switched to a load at the time the primary winding is shunted across the filter capacitor. The circuit provides dual inductor buck power stage operation while maintaining input-output isolation. Interleaved power processing provides continuous capacitance support for the output voltage produced by the power supply.
    Type: Grant
    Filed: March 23, 1990
    Date of Patent: April 16, 1991
    Assignee: Unisys Corporation
    Inventors: David W. Parsley, Hubert C. Martin, Jr.
  • Patent number: 4991075
    Abstract: A DC-DC converter comprises a switching element having a rise time t.sub.on and a fall time t.sub.off ; a control device for controlling the switching operation of the switching element; a transformer having a primary winding and a secondary winding, the primary winding being connected to a DC power source through the switching element, and having an open inductance L.sub.M ; an inductance coil having an inductance L connected to the secondary winding of the transformer; and a rectifying device for rectifying the output from the secondary winding of the transformer; assuming that the voltage applied to the primary winding of the transformer is E, the load current flowing through the transformer is I.sub.D, and the sum of the stray capacitance of the switching element and the distributed capacity of the windings of the transformer is C1, the following relational expressions being established:L>(E/I.sub.D)T.sub.onandL.sub.M >t.sub.off.sup.2 /.pi..sup.
    Type: Grant
    Filed: February 6, 1990
    Date of Patent: February 5, 1991
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Akira Saitou, Osamu Takahashi, Seigou Tsukada, Yasuyuki Sohara, Hideki Tsuruse, Hidehiko Sugimoto
  • Patent number: 4985820
    Abstract: A driver circuit for switching on lamps with low cold resistance. The circuit includes a power transistor (T5) of which the collector-emitter path is connected to the lamp (12) in a series circuit which lies between a positive terminal and a ground terminal of a supply voltage source. The circuit further includes an RC member comprising a resistor (R1) which is connected on one side to the ground terminal and a capacitor (C) which is connected in series with the resistor and on one side to the positive terminal of the supply voltage source. A comparator (38) compares the voltage at the resistor (R1) with the voltage at the collector of the power transistor (T5) and furnishes at an output a blocking signal for the power transistor (T5) when the voltage at the resistor (R1) is more negative than the voltage at the collector. A limiting member (T4) limits the voltage at the resistor (R1) to a voltage value lying above the saturation voltage of the power transistor (T5).
    Type: Grant
    Filed: May 5, 1989
    Date of Patent: January 15, 1991
    Assignee: Texas Instruments Deutschland GmbH
    Inventor: Anton Vorel
  • Patent number: 4959765
    Abstract: A quasi-resonant DC to DC converter having zero-current and zero-voltage switching includes a transformer with primary and secondary windings, and periodic switching means connected in series with the primary winding. The converter further includes an input capacitor parallel to the transformer's primary winding and an output capacitor parallel to the secondary winding. The topology of the converter is determined by selecting an input capacitor having a capacitance much lower than the output capacitor, by selecting the resonance period of a circuit including the input capacitor and the overall series inductance of the transformer to be shorter than the ON period of the periodic switching means, and by selecting the resonance period of a circuit including the overall parasitic capacitance, referred to the primary side of the transformer and the periodic switching means, and the magnetizing inductance of the transformer to be shorter than the OFF period of the periodic switching means.
    Type: Grant
    Filed: February 22, 1989
    Date of Patent: September 25, 1990
    Assignee: Agence Spatiale Europeenne
    Inventor: Alan Weinberg
  • Patent number: 4959764
    Abstract: A two switch, DC/DC converter provides sufficient inductive energy storage at the termination of the "on" period of each switch to alter the charge on the intrinsic and stray capacitance of the combination of switches producing zero voltage across the alternate switch prior to its turn on. A short dead-band between the turn on pulses provided by the control circuit allows time for this transition. Thus the energy stored in the capacitance of the switches is returned to the source and load rather than being dissipated in the switching devices. This greatly improves the efficiency of the converter particularly when operating at high frequency. The unique topology of the converter provides other new and useful characteristics in addition to zero voltage switching capaibility such as operation at constant frequency with pulse-width-modulation for regulation, quasi-square wave output current, and the ability to integrate the magnetic elements with or without coupling.
    Type: Grant
    Filed: November 14, 1989
    Date of Patent: September 25, 1990
    Assignee: Computer Products, Inc.
    Inventor: John A. Bassett
  • Patent number: 4933830
    Abstract: A switching power supply using a step-up transformer whose impedance viewed from its primary side is different from the impedance viewed from its secondary side whereby the inductance of its primary and secondary windings are settable independently of each other.
    Type: Grant
    Filed: April 27, 1989
    Date of Patent: June 12, 1990
    Assignee: Hitachi, Ltd.
    Inventors: Masayoshi Sato, Norikazu Tokunaga, Hisao Amano, Yasuo Matsuda
  • Patent number: 4930059
    Abstract: A switched mode DC/DC power converter for high outputs includes two parallel channels. Each channel consists of a flyback transformer (Fb-Tr1, Fb-Tr2) with a timed primary switch (S1, S2) on the primary side and a secondary switch (S3, S4) on the secondary side. The output flow within one channel from the primary supply voltage Ub through the primary power switch (S1; S2), the flyback transformer (Fb-Tr1, Fb-Tr2), and the secondary power switch (S3; S4) to the secondary output voltage (Ua1, Ua2) occurs, respectively, during the blockage phase. The two flyback transformers (Fb-Tr1, Fb-Tr2) are loosely linked with each through a link circuit (L.C.). The link circuit (L.C.) transmits energy from the transformer which is, respectively, in the forward phase to the other transformer. The power switches (S1, S3; S2, S4) are actuated by a control unit (C.U.) so as to be of correct frequency and phase.
    Type: Grant
    Filed: October 26, 1987
    Date of Patent: May 29, 1990
    Inventor: Winfried P. Rutt
  • Patent number: 4926304
    Abstract: A switched-mode power supply circuit for converting a DC input voltage into a DC output voltage comprises a series arrangement of a controllable power switch and an inductive element coupled between the input voltage terminals. Control means are provided for rendering the power switch alternately conducting and non-conducting and a rectifier is coupled to the inductive element for making the output voltage available. The inductive element and a capacitor coupled thereto form a part of a resonant circuit in which a voltage oscillation is present in the time periods when the switch and the rectifier are currentless. The circuit further comprises means for interrupting the oscillation present in the resonant circuit at an instant when the voltage across the inductive element or the current through the capacitor is substantially zero. In one embodiment, the dissipation in the circuit is reduced and the circuit is synchronized.
    Type: Grant
    Filed: May 4, 1989
    Date of Patent: May 15, 1990
    Assignee: U.S. Philips Corporation
    Inventor: Antonius A. M. Marinus
  • Patent number: 4870554
    Abstract: In a forward converter power supply comprising a transformer having a primary winding connected to a primary circuit and a secondary winding connected to a secondary circuit, and a switching transistor in the primary circuit, an active network snubber in the primary circuit for receiving and storing continuing current from the transformer primary winding upon switching of the transistor and for returning current through the transformer primary winding so as to resent the transformer and thereby returning parasitic energy in the transformer caused by leakage inductance and magnetizing current to the energy source.
    Type: Grant
    Filed: November 12, 1987
    Date of Patent: September 26, 1989
    Assignee: Power Systems, Inc.
    Inventor: Jerry J. Smith
  • Patent number: 4866590
    Abstract: Disclosed is a switching power source having a series connection composed of a main transformer, a current-suppressing inductance element, and a switching element and connected across a DC input power source, in which output windings are additionally wound on the main transformer and the inductance elements respectively and those output windings are connected in series to each other so as to form an auxiliary power source for a control circuit for driving/controlling the ON-OFF of the switching element, and a starting circuit is provided to supply power from the DC input power source to the control circuit only during the starting time of the switching power source.
    Type: Grant
    Filed: July 28, 1988
    Date of Patent: September 12, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Teruaki Odaka, Kunio Ishiyama, Shoichi Noguchi
  • Patent number: 4858093
    Abstract: An integrated magnetic power converter for supplying power to a load includes a continuous magnetic structure having first and second legs and a magnetic path therebetween. A primary winding is wound on the first leg. A first secondary winding is wound on the second leg and is connected to the load. A second secondary winding in series with the first secondary winding is wound on the first leg. A first circuit is connected to the primary winding for supplying energy to the power converter. A second circuit is connected to the secondary windings, and a third circuit is connected to the secondary windings for alternatively transferring energy to the load. When energy is supplied to the primary winding, a magnetic flux is produced in the magnetic path for transferring energy to the load via the first secondary winding and the third circuit, and an amount of energy is stored in the area surrounding the magnetic structure and the magnetic path.
    Type: Grant
    Filed: December 12, 1988
    Date of Patent: August 15, 1989
    Assignee: Qualitron, Inc.
    Inventor: Clayton L. Sturgeon
  • Patent number: 4841201
    Abstract: A stacked or laminated-layer type of flyback transformer includes a plurality of high voltage windings wound in regular order in a direction of the winding axis and arranged on the same core cylinder. The high voltage windings in the respective layers are connected in series with each other by diodes and so that a voltage is generated with a direction of stacking of these windings. A winding start position of the first layer high voltage winding nearest a primary winding is lagged with respect to the winding start positions of the second layer winding and subsequent layer winding. The winding start position of the first layer winding is selected to be the position of, for example, 0 to 25% when the winding width on the core cylinder is 100%.
    Type: Grant
    Filed: November 4, 1987
    Date of Patent: June 20, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Kazuyoshi Takizawa, Kiyoshi Watanuki
  • Patent number: 4837452
    Abstract: A method and apparatus are disclosed for controlling an off-line dc power supply circuit including a printed circuit board. The power supply circuit comprises a source of unregulated dc input power and a power transformer which separates the circuit into a primary side and a secondary side. An error amplifier compares an output dc voltage generated at a secondary winding of the power transformer to a reference voltage to generate an error signal representative of the difference error therebetween. The error signal is coupled from the secondary side of the power supply circuit to the primary side of the power supply circuit by means of a capacitor formed from traces on opposite sides of the printed circuit board. A solid state switch selectively connects the unregulated dc input power to a primary winding of the power transformer to regulate the power supply circuit in the primary side of the circuit in response to the error signal which is generated in the secondary side of the circuit.
    Type: Grant
    Filed: October 19, 1988
    Date of Patent: June 6, 1989
    Assignee: Spectra-Physics, Inc.
    Inventor: Donald S. Peterson
  • Patent number: 4833581
    Abstract: A power supply for a magnetron comprises an inverter circuit for converting a direct voltage obtained from a commercial frequency power source into an alternating voltage of a higher frequency by switching a switching element, a transformer with its primary winding connected to the inverter circuit, a voltage doubler with its input connected to a secondary winding of the transformer and with its output connected between a filament and an anode of a magnetron, and a resonant circuit formed in the voltage doubler for smoothing a current through the magnetron.
    Type: Grant
    Filed: October 13, 1987
    Date of Patent: May 23, 1989
    Assignees: Hitachi Ltd., Hitachi Automotive Eng. Co., Ltd.
    Inventor: Kunio Ishiyama
  • Patent number: 4829414
    Abstract: A circuit for generating a constant DC high voltage responsive to an input signal having various frequencies, having a frequency-voltage converter responsive to the input signal to generate a voltage signal corresponding to the frequency of the input signal. The voltage signal is applied to an oscillation circuit and a voltage control circuit, respectively, as a control signal. The output from the oscillation circuit is coupled to one terminal of a primary coil of a flyback transformer (FBT), and the output from the voltage control circuit is coupled to the other terminal of the primary coil of the flyback transformer (FBT).
    Type: Grant
    Filed: November 25, 1987
    Date of Patent: May 9, 1989
    Assignee: Goldstar Co., Ltd.
    Inventor: Keun J. Yook
  • Patent number: 4823248
    Abstract: High voltage generators are generally arranged to step up flyback pulses from a horizontal deflection circuit by means of a flyback transformer consisting of a primary low voltage coil and a secondary high voltage coil, rectifying the high voltage output through a rectification circuit for application to the anode of a cathode-ray tube. However, such a flyback transformer construction has an inherent drawback that the voltage of the high voltage output is varied by variations in the high voltage output current due to leakage inductance, resulting in load fluctuations.
    Type: Grant
    Filed: April 5, 1988
    Date of Patent: April 18, 1989
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Hiroshi Ikeuchi, Nobuaki Imamura
  • Patent number: 4814963
    Abstract: There is disclosed herein a modular, high power, flyback transformer based power supply with step up and step down capability. The power supply uses multiple flyback transformers having switching transistors which may be either connected to one terminal of the primary winding or which may be placed in the center of the primary winding. The switching transistors are driven by pulse trains which are out of phase with each other. This results in lowered RMS values for ripple current through the input and output capacitors. The flyback voltage transients may be used to step up or step down the input voltage by varying the pulse width of the pulses in the swicthing pulse trains. In embodiments where the switching transistors are placed in the middle of the primary windings, better suppression of radio frequency emissions and current in safety ground wires is achieved.
    Type: Grant
    Filed: September 30, 1987
    Date of Patent: March 21, 1989
    Assignee: Spectra Physics
    Inventor: Alan Petersen
  • Patent number: 4812959
    Abstract: A non-interfering power supply includes a free-running blocking oscillator power supply subsystem and a circuit arrangement that synchronizes the blocking oscillator power supply subsystem to operate at the horizontal operating frequency of a display subsystem. Synchronizing signals representative of the horizontal operating frequency of the display subsystem are generated and are used to activate the circuit arrangement that causes the blocking oscillator to change its mode of operation from free-running to a fully reset fixed frequency flyback converter. When activated, a switch in the circuit arrangement extends the off-time of a switching transistor in the blocking oscillator power supply control circuit. As a result, the oscillator is forced to run at an operating frequency lower than its free-running frequency.
    Type: Grant
    Filed: May 20, 1987
    Date of Patent: March 14, 1989
    Assignee: International Business Machines Corp.
    Inventors: Carleton D. Driscoll, Elie M. Najm, Manfred Waechter
  • Patent number: 4812960
    Abstract: A power feeding apparatus which is used in a high-frequency heater or the like, is further power-converted by a transformer after the power provided by the power supply such as commercial power supply or the like has been converted into the high-frequency power by a transducer including a semiconductor, feeds the converted power into the load having the unidirectional electrical current characteristics of magnetron or the like. The generating voltage is dropped so that the stable power may be fed without the corona discharge and the acr discharge to be caused, the insulating withstand voltage between the windings of the transformer, the pulling of the wirings, and the insulating withstand voltage may be reduced.
    Type: Grant
    Filed: December 11, 1987
    Date of Patent: March 14, 1989
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kazuho Sakamoto, Takao Shitaya, Shigeru Kusunoki, Naoyoshi Maehara, Takashi Niwa, Takahiro Matsumoto, Daisuke Bessyo
  • Patent number: 4809148
    Abstract: A full-fluxed, single-ended, DC converter is disclosed. The converter includes a transformer having primary and secondary windings magnetically coupled and wound about a common core. A regulation switch is connected in series with the primary winding and allows the primary current to be interrupted in a time-controlled fashion, causing the desired output characteristics to be achieved. The series combination of a storage capacitor and reset switch are provided in parallel with the regulation switch to initiate bidirectional magnetizing current flow in the primary winding and, hence, bidirectional flux excursions in the transformer core. As a result, power transfer characteristics are improved. In the preferred embodiment, the regulation and reset switches are complementary field effect transistors (FETs) whose sources and gates are tied together allowing their gates to be coupled to a single bipolar drive signal.
    Type: Grant
    Filed: October 21, 1987
    Date of Patent: February 28, 1989
    Assignee: British Columbia Telephone Company
    Inventor: Belwinder S. Barn
  • Patent number: 4809149
    Abstract: A controlled single-ended down converter comprises a transformer of d.c. separation of the input circuit and the output circuit, a switching element controlled in pulse width in the input circuit and a rectifier diode as well as a fly-wheel diode in the output circuit. During the conducting phase of the switching element, the transformer takes up magnetization energy. This energy is demagnetized through the barrier layer capacitance of the rectifier diode during the cut-off phase.
    Type: Grant
    Filed: June 5, 1987
    Date of Patent: February 28, 1989
    Assignee: U.S. Philips Corp.
    Inventor: Krahl Burghard
  • Patent number: 4805079
    Abstract: A switched voltage converter formed asymmetrically or symmetrically with one (S1) or two controlled semiconductor switches, respectively, connected in a series arrangement, with a first coil (L1) and a first semiconductor switching element (D1), for example, a diode. The coil is connected to a terminal of a first (C1) and a second (C2) capacitor. Arranged in parallel with the switch (S1) is a series arrangement of the first capacitor (C1) and of the parallel arrangement consisting of a second coil (L2) and a second diode (D2) in series and of a third diode (D3) and a third capacitor (C3) also in series. The junction point of the third diode (D3) and the third capacitor (C3) is connected to the first diode (D1) via a d.c. conection comprising a fourth (D4) and a fifth (D5) diode. The junction point of the fourth (D4) and a fifth (D5) diode is connected via the second capacitor (C2) to the junction point of the first coil (L1) and the first diode (D1).
    Type: Grant
    Filed: April 21, 1987
    Date of Patent: February 14, 1989
    Assignee: U.S. Philips Corp.
    Inventor: Marinus C. W. Van Buul
  • Patent number: 4803722
    Abstract: A circuit for remote supply of subscriber line terminals in telecommunication systems, especially suitable for employment in digital telecommunication systems, is described. The circuit comprises a supply circuit (10) at the beginning of the subscriber line (11), which circuit has a negative internal resistance operative when a preassigned supply amperage is exceeded. Between the subscriber line (1) and the terminal, a current converter cirucit (12) is provided, containing an energy reservoir (40) on the primary side and a switch-on circuit (41-44) operating in dependence upon its charge voltage for the switch pulses required for start-up. The operating current for the switch pulses is then delivered by a secondary winding (57) of the converter transmitter (27).
    Type: Grant
    Filed: April 10, 1986
    Date of Patent: February 7, 1989
    Assignee: Nixdorf Computer AG
    Inventor: Harald Schreiber
  • Patent number: 4802080
    Abstract: A power transfer circuit includes first and second windings (L1, L2) sharing a common magnetic core (101). Each winding has associated with it a parallel capacitor to thus form a pair of "tank" circuits. The first winding (L1) is connected at one end to a voltage supply and, at the other end, to ground through an FET switch (100,200). The switch (100,200) is turned on and off at a predetermined frequency and at a 50% duty cycle. The second winding (L2) and associated capacitor (C2) achieves parallel resonance at the predetermined frequency. Similarly the combined first and second windings (L1,L2) and associated capacitors (C1,C2) achieve parallel resonance at said predetermined frequency. The second winding (L2) need not be electrically connected to the first winding (L1) which transfers energy to it through the magnetic core (101). The transfer circuit efficiently couples power across a dielectric interface to a pickup coil (L3).
    Type: Grant
    Filed: March 18, 1988
    Date of Patent: January 31, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Information Systems
    Inventors: Burt J. Bossi, Mark A. Eberhart
  • Patent number: 4787020
    Abstract: Disclosed is a full-wave output type forward converter wherein a main transformer having a primary winding connected in series with a switching element includes two secondary windings as winding halves divided by a center tap and electromagnetically coupled. A leakage self inductance can be reduced to obtain a high-frequency, high-power arrangement.
    Type: Grant
    Filed: February 16, 1988
    Date of Patent: November 22, 1988
    Assignee: Nemic-Lambda K.D. and Densetsu Corporation
    Inventors: Rihei Hiramatsu, Tokunari Inoue, Kazushi Watanabe
  • Patent number: 4783727
    Abstract: A DC/DC converter has a transformer and a switching transistor provided with a discharge circuit and activated by an actuating circuit. The discharge circuit includes a choke in series with two reverse oriented diodes, and a capacitor connected between the junction of the diodes and the collector of the transistor. With this arrangement, the conventional demagnetizing winding of the transformer may be omitted. The duty factor may be chosen very high, to about 0.75, and the actuation of the switching transistor upon occurrence of a maximum negative magnetizing current may lead to a doubling of the usable induction.
    Type: Grant
    Filed: May 14, 1987
    Date of Patent: November 8, 1988
    Assignee: Eckhardt AG
    Inventor: Erhard Neumann
  • Patent number: 4774649
    Abstract: A resonant power converter is disclosed which is constructed on an integrated magnetic core, with primary, secondary and tertiary windings occupying separate legs of the core. The tertiary winding is connected in a resonant circuit and induces a flux in the primary leg that causes the primary winding current to assume the shape of a series of generally sinusoidal pulses. Primary winding switching can thus occur at zero primary current between pulses, thereby eliminating prior interference problems. Furthermore, the converter can be operated in a pulse width modulated mode to accommodate for varying output load levels without the problems of low frequency operation encountered by prior frequency modulated resonant converters.
    Type: Grant
    Filed: July 1, 1987
    Date of Patent: September 27, 1988
    Assignee: Power-One, Inc.
    Inventor: Michael P. Archer
  • Patent number: 4768141
    Abstract: The invention relates to a d.c.-a.c. converter with an asymmetric half-bridge circuit (1) that has an energy-storing component (6). The controllable switching means (2, 5) of the asymmetric half-bridge circuit (1) are driven by means of phase-shifted control pulses, the control pulses partly overlapping in time. The pulse width of the phase-shifted control pulses is substantially 180 electrical degrees.
    Type: Grant
    Filed: January 27, 1987
    Date of Patent: August 30, 1988
    Inventors: Guido Hubertus, Freidrich-Werner Thomas, Wolfgang Sperzel, Johann Sturmer
  • Patent number: 4767978
    Abstract: In the preferred and illustrated embodiment of a DC to DC power converter in a sonde and exposed to high temperatures, a transformer with primary and secondary provides AC to a full wave rectifier bridge. The bridge output is DC with ripple on it. The bridge output is connected serially to the primary winding and also to a shunt capacitor. The circuit provides high temperature performance including slower switching speeds, reduced power dissipation and wider current range.
    Type: Grant
    Filed: April 25, 1986
    Date of Patent: August 30, 1988
    Assignee: Halliburton Company
    Inventor: Starlin M. Reid
  • Patent number: 4763237
    Abstract: A power conversion apparatus are disclosed, each having a pair of transformers, each operating in transforming and rebiasing modes, whose primaries are joined in parallel and are alternately energized by way of a control circuit. Methods are also disclosed for converting power, utilizing a pair of transformers.
    Type: Grant
    Filed: October 17, 1986
    Date of Patent: August 9, 1988
    Inventor: John P. Wieczorek
  • Patent number: 4760512
    Abstract: A single ended forward converter includes a snubber/reset circuit that diverts current flow from the power switching transistor during the turn off transition to significantly reduce switching loss therein. This same circuit is further operative to resonate energy stored in the magnetizing inductance of the power transformer with a capacitor during a nonconducting period of the power switching transistor in order to reverse the polarity of current, in the magnetizing inductor and reset the core, and further obtain bipolar flux excursions in the transformer core during each cycle of operation.
    Type: Grant
    Filed: June 11, 1986
    Date of Patent: July 26, 1988
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Thomas P. Loftus
  • Patent number: 4739461
    Abstract: A power supply device capable of supplying high DC voltages of positive and negative polarities has a transformer having a primary coil and two secondary coils. A DC current supplied to the primary coil is switched to generate voltages in the secondary coils. These voltages are rectified and smoothed in mutually opposite polarities, and the output voltages are obtained by summing the rectified and smoothed voltages.
    Type: Grant
    Filed: September 3, 1986
    Date of Patent: April 19, 1988
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shunichi Komatsu, Koji Suzuki
  • Patent number: 4736285
    Abstract: A demagnetization circuit for use with a forward converter includes a drive winding magnetically coupled to the primary winding of the forward converter, a capacitor for absorbing leakage and magnetization energies from the primary winding when the forward converter is switched off, an inductor for absorbing energy from the capacitor, and a switching circuit for selectively connecting the inductor to the input voltage source of the forward converter.
    Type: Grant
    Filed: June 19, 1986
    Date of Patent: April 5, 1988
    Assignee: Veeco Instruments, Inc.
    Inventor: Itzchak Cohen
  • Patent number: 4736284
    Abstract: In a switching power supply circuit, a forward converter includes first to third switching transistors and a switching transformer having first and second primary windings. The first to third switching transistors are connected via series-connected first and second primary windings to a high voltage DC source. While the first to third transistors are simultaneously turned off, magnetic fluxes induced in the switching transformer are completely reset.
    Type: Grant
    Filed: December 29, 1986
    Date of Patent: April 5, 1988
    Assignee: Kikusui Electronics Corp.
    Inventors: Masaaki Yamagishi, Masahiko Shimizu
  • Patent number: 4731719
    Abstract: A switching voltage regulator circuit is provided which regulates an input voltage to an output voltage of lesser magnitude, and which supplies an output current greater than the current through the switch employed in the circuit. The circuit includes a transformer which causes output current to be provided both when the switch is open and when it is closed.
    Type: Grant
    Filed: November 19, 1986
    Date of Patent: March 15, 1988
    Assignee: Linear Technology Corporation
    Inventor: Carl T. Nelson
  • Patent number: 4731803
    Abstract: A circuit for operating an X-ray tube, such as in a medical diagnostics apparatus, is connected with a high-voltage generator and a switch mechanism for connecting and disconnecting the X-ray tube to the high-voltage generator. A resistor is disposed in a circuit branch which can be connected in parallel across the X-ray tube by a switch controlled by the aforementioned switch mechanism. If the X-ray tube is disconnected from the power source, the switch closes the circuit branch and causes the resistor to be connected across the X-ray tube. As a result, the X-ray tube voltage decreases relatively quickly after the high-voltage is disconnected. The resistor across the X-ray tube may be a variable resistor, such as a high-voltage triode.
    Type: Grant
    Filed: October 6, 1986
    Date of Patent: March 15, 1988
    Assignee: Siemens Aktiengesellschaft
    Inventors: Heinz-Erik Kranberg, Horst Hallmann
  • Patent number: 4725768
    Abstract: An inductor and a switching means are combined in such a way that the storage of the energy in the inductor and the release of the energy stored in the inductor are repeatedly carried out, whereby the released energy is rectified and smoothed to obtain a DC output. The inductor is fabricated from a conductor comprising a wire coated with a thin magnetic film in such a way that the easy axis of said thin magnetic film is extended substantially in the longitudinal direction of the wire. Furthermore, a plurality of inductor and switching element pairs are provided and are switched in different phases, respectively.
    Type: Grant
    Filed: November 6, 1986
    Date of Patent: February 16, 1988
    Assignee: Toko Kabushiki Kaisha
    Inventor: Shigetoshi Watanabe
  • Patent number: 4709319
    Abstract: There is disclosed a high-voltage power supply device capable of high precise control with a simplified circuitry and with a reduced energy loss in which a high-voltage transformer is controlled by switching means which is driven by a power source including a negative power supply and operated in response to pulse signals.
    Type: Grant
    Filed: September 15, 1986
    Date of Patent: November 24, 1987
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kazuyoshi Takahashi, Koji Suzuki, Joji Nagahira, Kunio Yoshihara, Toshiro Matsui, Tadashi Ishikawa
  • Patent number: 4704674
    Abstract: A power feed apparatus in which a means for by-passing the current reversely biasing the load is used for the normally used rectification means when the power converted by the transformer is fed to the reversely blocking characteristics like magnetron, whereby the price is lower and the shape is more compact without the use of the rectifier, because of the combination construction of the reverse bias current by-pass means and the inductance element provided in the load current path with respect to the non-linear load like the magnetron.
    Type: Grant
    Filed: May 14, 1986
    Date of Patent: November 3, 1987
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Naoyoshi Maehara, Takahiro Matsumoto, Shigeru Kusunoki, Kazuho Sakamoto, Makoto Mihara
  • Patent number: 4688157
    Abstract: The invention relates to switching circuits using fast rectifier diodes. To damp the oscillations liable to occur at the time when the fast diode passes from a conducting state into a blocked state, a supplementary diode with a lower blocking speed and a smaller current passage cross-section than the fast diode is positioned in parallel on the latter and with the same polarity. Application to cut off power supplies, undulators, converters, etc.
    Type: Grant
    Filed: January 7, 1986
    Date of Patent: August 18, 1987
    Assignee: Thomson-CSF
    Inventor: Klaus Rischmueller
  • Patent number: 4682093
    Abstract: In a power supply system, an inductance L is connected between a rail at a voltage V.sub.1 and a rail at earth through a switch S. When the switch is opened, a current i.sub.2 flowing from the inductance L is directed to a third rail through a diode D, voltage on the third rail rising to V.sub.2. The system may function as a dc to dc converter with an output voltage between the V.sub.1 rail and V.sub.2 rail equal to V.sub.2 -V.sub.1. The system may alternatively be used in, for example, a reluctance motor drive, in which case a further inductance with associated switch and diode is included in the circuit in inverse configuration to prevent excessive voltage rise on the third rail.
    Type: Grant
    Filed: October 18, 1985
    Date of Patent: July 21, 1987
    Assignee: Kollmorgen Technologies Corporation
    Inventors: John Murphy, Francis McMullin, Michael Egan, John V. Byrne, Patrick Kenneally
  • Patent number: 4675796
    Abstract: An integrated magnetic assembly for use in the direct current output circuit of a high frequency electronic switching power supply, comprising magnetic core sections for the output transformer and inductor windings and a common magnetic core segment completing the magnetic flux paths for the transformer and inductor windings. An auxiliary winding on one or both of the core sections is supplied with energy from the capacitor of a snubber circuit connected across the primary side of the magnetic output circuit. This auxiliary winding is magnetically coupled to the secondary side of the magnetic circuit to transfer energy to the power supply output during a portion of the switched current cycle.
    Type: Grant
    Filed: May 17, 1985
    Date of Patent: June 23, 1987
    Assignee: Veeco Instruments, Inc.
    Inventors: George A. Gautherin, Sol Greenberg
  • Patent number: 4674019
    Abstract: A transformer-coupled two-inductor buck converter is provided which comprises a series input circuit including an input inductor, a capacitor and a grounded inductor. The input and grounded inductors are wound so that a source of d.c. input voltage can be connected across positive polarity outer ends thereof. A transformer is provided for coupled the input and output circuits of the converter. When a switching transistor in the input circuit turns on, input current conducting through the input inductor joins with current being dragged out of the grounded inductor and through the capacitor to conduct through the primary winding of the transformer and couple to the secondary winding for delivery as output current to the load. An output winding coupled to the grounded inductor is connected by a switching diode to the load.
    Type: Grant
    Filed: April 16, 1986
    Date of Patent: June 16, 1987
    Assignee: Keller-Mullett Technology
    Inventor: Robert M. Martinelli