Abstract: Presented herein are methods and apparatus for biasing magnetic circuits to reduce audible noise from a switching power supply. A magnetic component (e.g., a magnet) is constructed and provided to a core (e.g., a ferromagnetic core) to offset (i.e., bias) an applied magnetomotive force. By selecting and/or manufacturing the magnetic component based on a circuit operating condition, the offset may be tailored to advantageously shift a frequency of mechanical deformation outside the audible noise range. In a switching power supply with fixed peak current, the offset to the applied magnetomotive force may be determined, at least in part, by the fixed peak.

Abstract: An object of the present invention is to provide a small-sized and highly heat-dissipative reactor and a DC-DC converter using the reactor. A reactor according to the present invention includes a plate bus bar, a core, and a heat sink. The core includes a middle leg portion. The heat sink cools the plate bus bar. The plate bus bar is formed such that a winding axis of a winding including the plate bus bar passes through the middle leg portion. A main surface of the plate bus bar is disposed in parallel with a direction of the winding axis and thermally connected to the heat sink via an insulating layer.

Abstract: Disclosed is a basic module of a magnetic core of a wound electrical transformer. The basic module includes first and second windings placed atop one another and made of first and second materials, respectively. The first material is a crystal having a saturation magnetization?1.5 T and magnetic losses less than 20 W/kg in sine waves having a frequency of 400 Hz, for maximum induction of 1 T, and the second material is a material having an apparent saturation magnetostriction less than or equal to 5 ppm and magnetic losses less than 20 W/kg in sine waves having a frequency of 400 Hz, for maximum induction of 1 T. The cross-sections of the first winding and cross-sections of the second winding satisfy (S1/(S1+S3); S2/(S2+S4)) of the first material, having a high saturation magnetization, compared to the cross-section of both materials together, is 2%-50%.

Abstract: There is provided a transformer including an E shaped and two I shaped magnetic cores and a first, second and third windings, wherein: one I shaped magnetic core is located between one side and a middle legs of the E shaped magnetic core, another is located between another side and the middle legs; there is an air gap on each of the two I shaped magnetic cores or two side or bottom legs of the E shaped magnetic core, the first winding is wound on a part of the magnetic cores where the air gap exists; the second and third windings are wound on the middle leg; and the first winding is connected in parallel with the second winding to constitute a primary winding; the third winding is a secondary winding. With the transformer provided by the disclosure, transformer winding loss can be reduced, and transformer efficiency can be improved.

Abstract: A maximum power output circuit for EHC and its design method are presented. The circuit is comprised of a magnetic core, that is, a primary coil and a secondary coil, with a load resistor and a capacitor parallel connected at the two ends of the secondary coil. The circuit enables the EHC to be always working at the maximum power output, thus realizing maximum power output of the energy harvesting power source.

Abstract: A tank for electrical equipment such as power transformers and shunt reactors has integral stiffeners for reinforcing the tank during overpressure conditions, such as during an arc fault. The stiffeners are formed of a material that is more ductile than the material to which the stiffeners are attached, such as the tank walls and cover. The tank with integral stiffeners allows for expansion of the internal volume of the tank during overpressure conditions, thus, increasing the flexibility of the tank and mitigating the risk of tank rupture.

Abstract: A drive circuit is used for driving a switching element. The drive circuit includes a detection unit and an integrated circuit. The detection unit detects a state of a controlled switching element and outputs a voltage signal corresponding to a detection result of the state. The integrated circuit receives the voltage signal via an input terminal for the detection result and controls the switching element based on the received voltage signal. The input terminal includes at least two input terminals that are connected to each other so as to receive the same voltage signal from the detection unit.

Abstract: A magnetic power converter has a core that has at least a first leg and a second leg. In addition, the magnetic power converter has an output coil positioned around the second leg and a toroid integrated into the first leg, the toroid comprising a permanent magnet and an first input coil, the input coil positioned relative to the permanent magnet, such that when an alternating current (A/C) is applied to the first input coil, permanent magnet magnetic flux produced by the permanent magnet is displaced and travels through the second leg.

Abstract: A ripple reduction circuit for use in a current doubler rectifier has first and second inductors coupled via a first coupling coefficient. The first and second inductors generate a first and a second ripple current, respectively. A third inductor is coupled to the first and second inductors; and an impedance is connected in series with the third inductor, wherein the circuit generates a third ripple current opposing the combination of the first and second ripple currents generated by the first and second inductors.

Abstract: The present disclosure provides for a voltage reference circuit for Radio Frequency Identification (RFID) tag circuit. Such a circuit is formed in a substrate that is lightly doped with impurities of a first polarity. A first transistor having a first source connected to a ground, a first gate doped with impurities of the first polarity, and a first drain connected to the first gate at a reference node, a reference current source to provide a reference current to the reference node for generating a first reference voltage at the reference node, and an additional component for receiving the first reference voltage are disclosed.

Abstract: A filter uses a special autotransformer that has a ferromagnetic core with a plurality of legs and flux return bars. A first coil is located on one leg, and a second coil is located on the same leg, but spaced from the first coil. The first coil and at least part of the second coil are connected in series to receive distorted alternating current and at least that part of the second coil is connected to an output terminal. Between the coils and extending at least part of the way from the first leg to an adjacent leg is a magnetic shunt assembly to divert part of the flux generated in the first coil by the alternating current so that that part does not link with the second coil. An air gap is located to link with the second coil to create an inductor in that coil by flux in the second coil, and a capacitor is connected across the second coil to tune it to the fundamental frequency of the alternating current and substantially reduce harmonics in that current.

Abstract: A DC voltage from a DC supply is applied to inverters of two power supply units connected in parallel with each other. The inverters convert the received DC voltages into high-frequency voltages, which are, in turn, voltage-transformed in transformers. The outputs of the transformers are rectified in two rectifiers, respectively, and smoothed in two reactors. The smoothed voltages are supplied between output terminals. The reactors are formed on a single core, being loosely coupled with each other.

Abstract: In a transformer wound on a core having three or more legs (N legs), N−1 of the legs can have a flux distribution winding on them comprising flux distribution coils on each of the N−1 legs. The flux distribution coils are all connected together, usually in phase, so all of the coils see the same voltage. If the several coils have different numbers of turns, then the volt per turn will differ inversely, and so too will the flux in the N−1 legs. The flux in the Nth leg is the algebraic sum of the flux in the N−1 legs, and is usually the “Main” flux path. A winding around one of the legs would have a terminal voltage proportional to the number of turns and the flux in the leg. A winding may make several turns around the main leg of the transformer, then make one or more turns around a side leg having a different flux, usually some fraction of the flux in the main leg. The extra turns, having a fractional flux, are the equivalent of a fractional turn.

Abstract: The present invention discloses a saturable reactor and a method for decoupling the interwinding capacitance from the frequency limitations of the reactor so that the equivalent electrical circuit of the saturable reactor comprises a variable inductor. The saturable reactor comprises a plurality of physically symmetrical magnetic cores with closed loop magnetic paths and a novel method of wiring a control winding and a RF winding. The present invention additionally discloses a matching network and method for matching the impedances of a RF generator to a load. The matching network comprises a matching transformer and a saturable reactor.

Abstract: A circuit for delivering an accurate reference current independent of operating frequency that is implementable on-chip and that is relatively insensitive to process and temperature variations. A frequency source controls a rate of charge transfer via a switched capacitor to generate a constant current over different frequencies. A complimentary doped FET provides a band gap voltage imposed over a known resistance to generate the output current.

Abstract: Feedback and associated electronic control circuitry are eliminated in a battery charger incorporating a ferroresonant transformer for providing a constant current to a charging battery as typically required such as during the final hours of charging. The ferroresonant transformer includes an input primary winding, an output secondary winding, and a regulating winding in combination with a tuned reactor for maintaining transformer minimum output current constant, the precise value of which can be established by transformer and tuned reactor values as well as the value of a resonating capacitor. As the battery approaches full charge and the charger's current approaches minimum value, the charger's output voltage automatically is adjusted to maintain the selected current. The battery's state of charge which dictates the load on the charger changes the amount of energy flowing in the tuned reactor and regulating winding.

Abstract: A current mirror constant current source circuit includes a first current mirror circuit constituted by first and second source-grounded n-channel MOS transistors connected to form a current mirror. A source-drain path of the first MOS transistor forms an input current path of the current mirror circuit, and a source-drain path of the second MOS transistor forms an output current path of the current mirror circuit. A current source is connected between a drain of the first MOS transistor and a high voltage supply line. A third n-channel MOS transistor is connected to have a source and a drain connected to a source and a drain of the first MOS transistor, respectively. A gate of the third MOS transistor is connected to the high voltage supply line. The current source includes a second current mirror circuit formed by two MOS transistors such that the source-drain path of one of the two transistors forms an output current path of the second current mirror circuit.

Abstract: An alternating current conditioner is provided with a magnetic structure that provides smoothing, transient suppression, ride through and power factor correction. The structure has a gapped magnetic core and primary and secondary windings. A shunt is provided between the primary and secondary, with the gap being on the primary side. A capacitor is in series with the secondary winding. The capacitor and the shunt inductance provide an LC low pass filter. The inductance caused by the gap cancels the capacitive effect of the LC filter.

Abstract: A ferroresonant three-phase constant AC voltage transformer comprising three transformer iron cores with one for each corresponding input supply phase, primary windings and secondary windings formed on each of the transformer iron cores, series reactance components or reactors connected in series, with the primary windings, automatic voltage regulating means for controlling secondary output voltages generated at the secondary windings to a predetermined target value, compensating windings formed so as to be inductively coupled to each of the series reactance components or reactors, and means for connecting the compensating windings in series with each other to form a closed loop circuit. The secondary output voltages are theoretically kept in balanced condition even when the loads or the primary input voltages or both are unbalanced.

Abstract: Primary and secondary windings of each transformer in a three-phase system each form a pair of independent windings, the first winding of each of the primary and secondary pairs formed on the iron core of one of the transformers and the second winding of each of the primary and secondary pairs formed on the iron core of the transformer adjacent thereto are connected in series to each other. These serially connected windings are regarded as one phase winding respectively, and they are connected to each other in either a delta connection or a Y connection. A variation in the voltage phase caused by a change in the load current of one of the system outputs has an influence not only on the phase of the voltage at that output but also on the phase of the voltages on the outputs adjacent thereto and consequently enables the deviation in the phase difference between the output phase voltages due to loss of balance of the load to be decreased to about one half.

Abstract: An energy convertor for generating a power output waveform that contains a fundamental sine wave and a controlled amount of the third harmonic wave to eliminate the sinusoidal peaks and to provide a desired flat top at reduced amplitude. The synchronized generation of the third harmonic is achieved in combination with a new inductor that enhances the harmonic in the magnetic path around the inductor.

Abstract: The transformer comprises a three-limbed magnetic core having two outer limbs each defining a central air gap. Two windings, an alternating current one and a direct current one, are wound around each outer limb. Primary and secondary windings are disposed on the center limb, the primary one being supplied with alternating current from a source, and the secondary one supplying with alternating current an external load. The two alternating current windings are connected in series and supplied with alternating current by the source, possibly through an additional winding wound around the center limb, while the two direct current windings are connected in series and supplied by the current in the alternating current windings rectified through a diode bridge. The current in the two direct current windings induces a magnetic flux in a closed circuit defined by the outer limbs.

Abstract: A transformer assembly suitable for use in very high frequency (VHF) switching power supplies that maintains a low leakage inductance between critical transformer windings while complying with the physical and electrical requirements imposed by standards for primary to secondary isolation. The transformer includes a telescopic bobbin assembly with an inner and an outer section that telescope together to form an interior clearance space or chamber between the two sections. The interior chamber has a narrow conduit exiting to the exterior of the bobbin assembly. Described are two embodiments for a transformer used in a forward-averaging type converter and a third embodiment for a transformer used in a frequency modulated converter.

Abstract: An improved magnetic core transformer for use as a voltage stabilizer in gas discharge lamps and tube circuits. The transformer has a magnetic stack length greater than either side of the magnetic cross-section and a floating shunt assembly constructed from stacks of magnetic strips. The stack length is optimized technically and as a function of the cost of iron and copper utilized in the transformer and when conformed with an optimum shunt a greater leakage inductance variation is achieved.

Abstract: Power conditioning apparatus particularly suited for computer facilities and including non-linear input chokes connectable with line power. These chokes are structured having a center leg configured to define a varying gap having a narrowest flux transfer region located centrally with respect to a surrounding shell structure. The gap configuration expands uniformly outwardly from this narrowest region. The outputs of the input chokes are serially, magnetically coupled through primary windings to pulse saturable reactors of a synthesizing network which includes a capacitor bank and operates to synthesize a sinewave output. The capacitance values of the capacitor bank are selectively distributed between the primary, isolation windings and the pulse saturable secondary or regulator components of the synthesizer network to achieve important improvements in system efficiency.

Abstract: Power conditioning apparatus particularly suited for computer facilities and including non-linear input chokes connectible with line power. The outputs of the input chokes are serially, magnetically coupled through primary windings to pulse saturable reactors of a synthesizing network which includes a capacitor bank and operates to synthesize a sinewave output. Series tuned traps are coupled to the synthesizer network to avoid the development of harmonics above fundamental.

Abstract: A ferroresonant transformer includes a drive winding wound around a thin strip of magnetic material and coupled to a high frequency voltage source. The drive winding is resonated with a capacitance for saturating the core portion of the strip under the drive winding. A load winding, separated from the drive winding sufficiently to provide substantial magnetic decoupling, via air, for example, is resonated with a capacitance to saturate the core portion of the strip under the load winding for providing a regulated output voltage across the load winding.