Saturable Reactor (e.g., Magnetic Amplifier) Patents (Class 363/91)
  • Patent number: 4791542
    Abstract: A power supply is disclosed which comprises a ferroresonant circuit, the ferroresonant circuit including a transformer with a core of magnetic material, a primary winding, a secondary winding, and reactive means coupled with at least one of the windings. The transformer also has at least one bias winding. An alternating voltage is applied to the ferroresonant circuit, the alternating voltage having a frequency that is approximately equal to a resonant frequency of the ferroresonant circuit. An output circuit is coupled to the secondary winding. A signal from the output circuit is applied as a feedback signal to the bias winding to control DC flux bias of the core. In an illustrated embodiment, the means for applying an alternating voltage signal to the ferroresonant circuit includes an oscillator for generating alternating voltage control signals, and a switching circuit responsive to an input power source for generating the alternating voltage signals under control of the oscillator.
    Type: Grant
    Filed: August 3, 1987
    Date of Patent: December 13, 1988
    Assignee: RFL Industries, Inc.
    Inventor: Andrew D. Piaskowski
  • Patent number: 4736283
    Abstract: An improved switching power source in which the output of the DC input power source is switched off and on under control of switching elements of an oscillating drive circuit which is supplied to the primary side of a power source transformer and from which a constant voltage output is supplied from the secondary of the transformer. A saturable reactor transformer supplies an input to the control terminals of the switching elements of the oscillating drive circuit and the inductance of the saturable reactor transformer is controlled with the output voltage from the secondary of the power source transformer so as to control the oscillating frequency of the oscillating drive circuit and, thus, stabilize the output voltage at the secondary of the power source transformer so as to obtain an increased conversion efficiency, reduce the size and weight of the transformer, reduce the leakage flux, improve the control range and reduce the cost of production.
    Type: Grant
    Filed: September 12, 1986
    Date of Patent: April 5, 1988
    Assignee: Sony Corporation
    Inventor: Masayuki Yasumura
  • Patent number: 4674022
    Abstract: An improved priming and sweep-out circuit in which losses are obviated or minimized by transferring energy resulting from such processes back to the power supply, and wherein a single common storage inductance is used in a secondary winding circuit of a saturable-core inductor transformer, the primary of which is series-connected in the SCR-switching energy storage and discharge pulse generating circuit, to serve both in the priming and sweep-out functions, and wherein reset circuit inductance does not participate in the energy transfer or storage functions.
    Type: Grant
    Filed: July 1, 1986
    Date of Patent: June 16, 1987
    Assignee: Megapulse, Inc.
    Inventor: Peter Ver Planck
  • Patent number: 4661898
    Abstract: A circuit is provided having an alternating current input and a synchronous switch means which has a control coil--such as a saturable reactor--with the input, so as to control the energy throughput of the synchronous switch means and therefore the output of the circuit. The current through the control coil is sensed and maintained in such a manner that the ampere-turns ratio of the control coil is maintained constant, thereby ensuring that the output of the circuit will be at a constant current irrespective of the internal resistance of the control coil or changes of that resistance. The output of the circuit may be an alternating current; more generally, it would be a direct current for such use as a battery forming and charging circuit.
    Type: Grant
    Filed: April 19, 1985
    Date of Patent: April 28, 1987
    Inventor: Alfred M. Hase
  • Patent number: 4626976
    Abstract: A magnetically controlled switching regulator which controls an output voltage using a saturable reactor, wherein the saturable reactor is constituted by a first winding through which an output current flows and a second winding through which a reset current flows. The energy for resetting the saturable reactor is supplied from a capacitor in a smoothing circuit for an output voltage. A turn ratio between the first and second windings is set so that a sufficiently high reset voltage is obtained. Since the reset current of the saturable reactor does not flow through a transformer, the saturation of the transformer and a high increase in temperature thereof do not occur, so that the core of the transformer can be miniaturized and a high gain of the output voltage control circuit can be derived.
    Type: Grant
    Filed: January 23, 1985
    Date of Patent: December 2, 1986
    Assignees: Hitachi, Ltd., Hitachi Metals, Ltd.
    Inventors: Kozin Abe, Kenichi Onda, Kohei Yabuno, Shin Nakajima, Noboru Ogawa
  • Patent number: 4620144
    Abstract: An electric power apparatus, namely a variable inductor comprising a magnetic core provided with a center limb and two outer limbs all having first and second ends. The first ends are interconnected through a first common point of the magnetic core, and the second ends through a second common point of this core. Two primary windings disposed respectively around the two outer limbs are connected in series and supplied with an alternating current, while two control windings also connected in series are respectively superposed to the two primary windings. The alternating current of the primary windings is rectified through a diode bridge for supplying with direct current the control windings.
    Type: Grant
    Filed: May 15, 1985
    Date of Patent: October 28, 1986
    Assignee: Hydro-Quebec
    Inventor: Leonard Bolduc
  • Patent number: 4591966
    Abstract: An improved rectifying network employing a semiconductor diode, a saturable reactor connected in series with the diode between a pair of terminals, and means for biasing the saturable reactor to saturate the saturable reactor core for forward diode current flow.
    Type: Grant
    Filed: May 19, 1983
    Date of Patent: May 27, 1986
    Inventor: Steve Smith
  • Patent number: 4532582
    Abstract: A voltage regulator system for receiving relatively high frequency electrical energy from a source and providing a regulated relatively low frequency electrical energy output wherein a passive device sensing means comprising only electrically passive elements senses the output voltage of the outputted relatively low frequency electrical energy and provides at least one output control signal proportional to the sensed output voltage, and at least one magnetic controller for receiving the control signal provided by the passive device sensing means and controllingly varying the relatively high frequency electrical energy in response to the received control signal to controllingly vary the voltage of the outputted relatively low frequency electrical energy to maintain the outputted relatively low frequency energy voltage at substantially a predetermined value.
    Type: Grant
    Filed: February 14, 1983
    Date of Patent: July 30, 1985
    Assignee: Power Technology Partners, Ltd.
    Inventor: Charles C. Freeny, Jr.
  • Patent number: 4462069
    Abstract: A multiple output d.c. to d.c. regulating circuit including an input protection circuit for providing protection against input overcurrent, input transient voltages, sustained input overvoltage and input polarity reversal. The protection circuit powers a d.c. to a.c. inverter which generates high frequency square-wave signals. The square-wave signals are fed to a magnetic saturable reactor regulator which has its controlled windings connected by a rectifying filtering network to a pair of main output terminals and connected by transformer rectifier filter circuits to a plurality of auxiliary output terminals. The d.c. output voltage across the main output terminals is sampled and is compared to a reference voltage of an integrated circuit operational amplifier. The output of the integrated circuit operational amplifier is connected to the control winding of the saturable reactor for controlling the controlled windings so that the square-wave signals are pulse width modulated to regulate the d.c.
    Type: Grant
    Filed: August 14, 1981
    Date of Patent: July 24, 1984
    Assignee: American Standard Inc.
    Inventor: Raymond Becky
  • Patent number: 4460955
    Abstract: A stabilizing power supply apparatus including, as a switching element, a magnetic amplifier supplied with a rectangular wave voltage produced by an inverter and controlled by a reset current. An error sensing circuit senses a difference between the output voltage of the magnetic amplifier and a reference voltage to produce an error signal corresponding to the sensed difference. An amplifier circuit amplifies the error signal into the reset current for the magnetic amplifier. The amplifier circuit includes a NPN-type transistor for amplifying the control current into the reset current and first and second diodes. The first diode has an anode terminal connected to a negative power supply line and a cathode terminal connected to the collector of the transistor in order that charge will not accumulate on the transistor base. The second diode has an anode terminal connected to the emitter of the transistor and a cathode terminal connected to the magnetic amplifier.
    Type: Grant
    Filed: December 22, 1982
    Date of Patent: July 17, 1984
    Assignee: Fanuc Ltd.
    Inventors: Masayuki Hattori, Shigeo Nakamura
  • Patent number: 4451876
    Abstract: A switching regulator of the magnetic amplifier type comprises a saturable reactor whose core ismade by winding a sheet of an amorphous metallic magnetic material into a toroidal form. The sheet thickness of the amorphous material is preferably between 4 .mu.m and 60 .mu.m so that a coercive force has a small value enough to minimize an undesirable temperature rise. The amorphous material has a composition expressed by MaM'bXc, where M is Fe and/or Co, M' is a metallic element other than Fe and Co, M' is a nonmetallic element, a, b and c are in the conditions of a .gtoreq.50, b.ltoreq.30 and c.ltoreq.30 respectively, and a+b+c=100.
    Type: Grant
    Filed: May 19, 1982
    Date of Patent: May 29, 1984
    Assignee: Hitachi Metals, Ltd.
    Inventor: Yasunobu Ogata
  • Patent number: 4441149
    Abstract: A multi-voltage transformer input circuit, which may have multi-phase input, and where the input or each phase of the input has a primary reactor voltage control, is provided by the present invention. The primary winding of the transformer, or each phase of the primary winding has at least two sections which are bifilar wound on a single core, each section having its own polarity. Each primary winding section is connected with one of a pair of like synchronous operating current control devices, which may be saturable core reactors, magnetic amplifier, or phase-angle fired silicon controlled rectifiers. Each synchronous operating device is in series with its respective primary winding section, the first in opposite polarity to the first primary winding section, the second with the same polarity as the second primary winding section.
    Type: Grant
    Filed: February 16, 1982
    Date of Patent: April 3, 1984
    Inventor: Alfred M. Hase
  • Patent number: 4435747
    Abstract: This disclosure relates to a system for supplying a stable DC high voltage to a load by resonantly driving a high voltage transforming circuit comprising a VLT and a capacitor type multiple boosting circuit. The system includes a VLT, a capacitor type multiple boosting circuit and a pulse-amplitude feedback control circuit designed to detect supply voltage to load, to compare the detected voltage with reference voltage and to control the voltage of the control winding of VLT by using the deviation produced by the comparison as a control signal.
    Type: Grant
    Filed: December 22, 1982
    Date of Patent: March 6, 1984
    Assignee: Kabushiki Kaisha Morita Seisakusho
    Inventors: Shuhei Furuichi, Toshiaki Ikeda, Masakazu Suzuki
  • Patent number: 4375077
    Abstract: A circuit for regulation of a D.C. output voltage in a switching power supply. The circuit contains a control transformer having primary, secondary and control windings. The output of the circuit is connected from the primary and secondary windings and is controlled by a switching element connected from the control winding. The circuit output error is provided to duty cycle modulation circuitry which varies the duty cycle of the switching element, thereby controlling the output voltage level.
    Type: Grant
    Filed: February 26, 1981
    Date of Patent: February 22, 1983
    Assignee: Data General Corporation
    Inventor: James B. Williams
  • Patent number: 4339792
    Abstract: A voltage regulator using a saturable transformer comprises a transformer having a primary and secondary windings, an AC power source for supplying the primary winding a fluctuating alternating current, and a rectifier connected to the secondary winding for rectifying an AC voltage derived therefrom to produce a DC output voltage. The transformer includes a core having four legs and two common portions magnetically joining the four legs, and a control winding supplied with DC control bias from a control circuit. The primary and secondary windings are wound on the first and second legs and the control winding is wound on the first and third legs.
    Type: Grant
    Filed: April 8, 1980
    Date of Patent: July 13, 1982
    Inventors: Masayuki Yasumura, Yoshio Ishigaki
  • Patent number: 4305032
    Abstract: A saturable reactor regulated power supply utilizes a power oscillator to convert line voltage to a higher frequency voltage. The high frequency voltage is passed through the gate windings of a saturable reactor to an output circuit including an output power transformer. A feedback circuit interconnected between the output circuit and control windings of the saturable reactor controls the control winding current in order to pulse modulate the voltage applied to the output circuit. The feedback circuit includes several resistors which are connected to cause a phantom control winding resistance R.sub.c * which is much greater than that of a control winding series resistor R.sub.1. The created phantom resistance R.sub.c * causes the control winding circuit time constant to be substantially less than that which would otherwise be provided by the series resistor R.sub.1 ; whereas, the resistor R.sub.1 determines the control winding power loss.
    Type: Grant
    Filed: June 12, 1979
    Date of Patent: December 8, 1981
    Inventor: Alan G. V. Grace
  • Patent number: 4302805
    Abstract: A regulated power supply includes an oscillating inverter circuit for generating a high frequency square wave signal that drives a saturable reactor which pulse-width modulates the square wave as a function of a control current through a control winding on the saturable reactor. The output voltage generated by the power supply in sensed by a feedback circuit and fed back as a modulating signal of the control current through the saturable reactor control winding to vary the power transferred by the saturable reactor to an output transformer. The variation in power supplied to the output transformer compensates the output voltage as sensed by the feedback circuit. A protective circuit is provided to sense an output overvoltage condition and inactivate the power supply by terminating the oscillation of the inverter.
    Type: Grant
    Filed: February 26, 1980
    Date of Patent: November 24, 1981
    Assignee: Kyber Engineering, Inc.
    Inventors: Alejandro Marez, Jon J. Spykerman
  • Patent number: 4217632
    Abstract: A regulated power supply system is disclosed including a source of unidirectional electric current, and at least one switch device including a saturable reactor controlled between a saturated condition and an unsaturated condition in a duty cycle such that the load voltage tends to remain constant with varying load current. In one embodiment, a pair of switch devices are coupled, respectively, between the ends of a center-tapped secondary winding of a transformer having a primary winding fed from an inverter, and a pair of rectifier devices coupled to provide the unidirectional current to the load. Control of the switch devices is effected by applying an appropriately varying control voltage to like electrodes of respective inverted control diodes each coupled to the junction between a respective switch device and its associated rectifier device. The control diodes are driven from the output of a comparator amplifier responsive to the difference between the load voltage and a reference voltage.
    Type: Grant
    Filed: July 10, 1978
    Date of Patent: August 12, 1980
    Assignee: Gould Advance Limited
    Inventors: Peter A. Bardos, John E. Crowe
  • Patent number: 4213084
    Abstract: A variable leakage transformer or a variable voltage transformer comprising a magnetic core with a main magnetic path and a sub-magnetic path, the main magnetic path having at least a common magnetic path with the sub-magnetic path, a primary winding wound on said common magnetic path of the core, a secondary winding wound on said main magnetic path of the core, and means for controlling the magnetic flux in said sub-magnetic path. By controlling the magnetic flux in the sub-magnetic path, the leakage of the flux induced by the primary winding from the main magnetic path to the sub-magnetic path can be controlled, thus the coupling between the primary and secondary windings, and conduction period in each cycle of the AC output voltage are controlled. The control of the conduction period in each cycle provides the control of the power transmitted from the primary winding to the secondary winding.
    Type: Grant
    Filed: March 9, 1978
    Date of Patent: July 15, 1980
    Assignee: TDK Electronics Company Limited
    Inventor: Hirayama Hiromitsu
  • Patent number: 4130790
    Abstract: An electrical power supply for providing an electrical power signal of substantially constant voltage when the current level of the power signal is less than a predetermined value and for reducing the voltage of the power signal below said predetermined level when the power signal current level exceeds the predetermined value includes a ferroresonant transformer. A saturable reactor provides a current responsive impedance connected to the primary of the ferroresonant transformer for reducing the voltage supplied to the primary winding. The maximum current level in the secondary circuit of the ferroresonant transformer is adjusted by adjusting the effective impedance of the saturable reactor. A rectifier may be connected in the secondary circuit of the ferroresonant transformer to provide direct current electrical power signal.
    Type: Grant
    Filed: April 25, 1977
    Date of Patent: December 19, 1978
    Assignee: Hobart Brothers Company
    Inventor: Larry E. Heisey
  • Patent number: 4092709
    Abstract: A multiple output switching regulator power supply operates as a self-oscillating circuit with a light weight ferrite core transformer and a sense winding used exclusively for voltage regulation purposes. A power transistor switch is employed to selectively connect the transformer primary across a DC source of power to provide energy storage when the switch is closed and to provide energy transfer when the switch is open, by way of transformer flyback. The power transistor switch is controlled by a feedback circuit which includes a current sink connected to selectively divert current away from the base of the power transistor switch and a timing circuit for controlling the operation of the current sink. A capacitor, connected across the sense winding is monitored by a high gain voltage comparison circuit which activates the timing circuit in dependence on the voltage variation on the capacitor.
    Type: Grant
    Filed: September 24, 1976
    Date of Patent: May 30, 1978
    Assignee: Texas Instruments Incorporated
    Inventors: William C. Voigt, William F. Jergens
  • Patent number: 4055740
    Abstract: An induction heating apparatus includes a saturable reactor having a pair of rectangular ferrite cores. An air gap is provided in each ferrite core to provide a gradually increasing saturation characteristic on the magnetization curve of the cores. A pair of series-connected load windings is coiled around each core and a control winding is coiled around a common magnetic path of the cores. A power control circuit produces a DC control current that passes through the control winding. The high frequency energization current is passed through the load windings. Means are provided to control the DC control current at a desired setting. Preferably, the actual power level is detected to control the DC current through a feedback loop.
    Type: Grant
    Filed: March 15, 1976
    Date of Patent: October 25, 1977
    Assignee: Matsushita Electric Industrial Company
    Inventors: Masatatsu Nakamura, Hideyuki Kominami, Keizo Amagami, Takao Kobayashi, Tadao Toyooka