Abstract: A switching circuit, electrical energy converter, power management unit and energy harvesting system are described. Such apparatus is applicable to energy harvesting applications which involve a variety of transducers, either singly or simultaneously. The transducers may, for example, be photovoltaic, thermoelectric, piezoelectric, or electrodynamic. The described converters operate to convert impedances, voltages and currents. They incorporate inductive energy transfer elements, which are magnetically coupled. Different combinations of these energy transfer elements are used to obtain different conversion ratios, which can be referred to as “gears”. On the input side, having multiple gears enables easier and better matching to a wider variety of energy transducers. On the output side, it enables easier and better accommodation of a wider spread of energy storage voltages and of a wider variety of loads.

Abstract: A planar matrix transformer assembly. In one embodiment, the assembly comprises (a) a core comprising multiple center posts in a matrix pattern; and multiple edge posts along edges of the core for a magnetic flux return path; (b) a single-turn layer comprising a top winding on the top the layer to form a single turn around each center post; and a bottom winding electrically coupled to the top winding and on the bottom of the layer to form a single turn around each center post; and (c) a multi-turn layer comprising multiple top-side windings on top of the layer, wherein each top-side winding is a multi-turn winding around a different center post; and multiple bottom-side windings on the bottom of the multi-turn layer, wherein each bottom-side winding is (i) electrically coupled to a different top-side winding in a one-to-one correspondence, and (ii) a multi-turn winding around a different center post.

Abstract: A high voltage transformer arrangement for supplying power to a high voltage tank assembly is disclosed. The high voltage transformer arrangement includes a first core arranged in the high voltage tank assembly and a secondary winding configured on the first core, a second core positioned outside of the high voltage tank assembly and at a predefined distance from the first core, and a primary winding configured on the second core. The second core and the primary winding transfers current received from an external power source to the first core and secondary winding for supplying power to the high voltage tank assembly.

Abstract: A switching power supply includes a first switching element, a rectifying element, a first inductor and a second inductor. The first switching element supplies a power supply voltage to the first inductor and al lows a current to flow when the first switching element is on. The rectifying element is connected in series to the first switching element, and allows a current of the first inductor to flow when the first switching element is turned off. The second inductor is electromagnetically coupled to the first inductor, a potential to turn on the first switching element is induced when the current of the first inductor increases, and a potential to turn off the first switching element is induced when the current of the first inductor decreases. The induced potential is supplied to a control terminal of the first switching element. The rectifying element includes a diode and a second switching element.

Abstract: The invention relates to the arrangement of a stepping switch on a control transformer, wherein either only the mechanical contact system (8) of the stepping switch or also its load changeover switch (7) is or are arranged within the tank (1) of the transformer, under the transformer cover (4) and above the iron yoke (3).

Abstract: A sample-and-hold (SAH) current estimating circuit and a first switching power supply are disclosed. The first switching power supply provides a first switching power supply output signal based on a series switching element and a setpoint. The SAH current estimating circuit samples a voltage across the series switching element of the first switching power supply during an ON state of the series switching element and during a ramping signal peak to provide an SAH output signal based on an estimate of an output current of the first switching power supply output signal. The first switching power supply selects the ON state of the series switching element, such that during the ramping signal peak, the series switching element has a series current having a magnitude, which is about equal to a magnitude of the output current of the first switching power supply output signal.

Abstract: When a commercial power supply E operates normally, converter sections PFC1, PFC2 connected in parallel to each other can operate to approximate the input current from the commercial power supply E to the waveform and phase of the input voltage to correct a power factor while supplying stabilized output voltages Vo1, Vo2 to a load. When the voltage of the commercial power supply E drops, the smoothing capacitor Co1 operates as an input power supply to power the converter section PFC2, which allows the smoothing capacitor Co2 to supply the stabilized output voltage Vo2 to the load.

Abstract: A converter has a main feedback path and two auxiliary feedback paths from an output node to an auxiliary differential input pair of a comparator. The auxiliary feedback paths have different RC time constants so that a differential ramp signal is effectively applied to the auxiliary differential inputs of the comparator. The circuit design compensates for a negligibly small equivalent series resistor of an output capacitor so that modern capacitors may be used without compromising the stable oscillation of the converter.

Abstract: Methods and apparatus are provided for operation of a voltage source inverter. A method of operating a voltage source inverter having an output with multiple voltage phases having a DC voltage level, the method comprising sensing a low output frequency condition; determining a DC voltage offset responsive to the low output frequency condition; and applying the DC voltage offset when operating the voltage source inverter resulting in a change to the DC voltage level of the multiple voltage phases.

Abstract: An improved Single-Stage Buck-Boost inverter (S2B2 Inverter) is provided, using only three or four power semiconductor switches and two coupled inductors in a flyback arrangement. The inverter can handle a wide range of dc input voltages and produce a fixed ac output voltage. The inverter is well suited to distributed power generation systems such as photovoltaic and wind power and fuel cells, for standalone or grid connected applications. The inverter has a single charge loop, a positive discharge loop and a negative discharge loop.

Abstract: A novel voltage switching device operable under a first and a second source voltages is disclosed. The device, which is capable of converting one of the source voltages to the design voltage of an electrical appliance when the two are different, comprises a connector having voltage indicators representing the first and the second voltage switching positions, respectively; and a voltage switching plug having a groove and a pair of fuses for the different source voltages. The connector, in one of the embodiments, may have two pairs of guide slots arranged in a perpendicular relationship between the two pairs. The plug may have a pair of complementary members apt to be selectively engaged with any one pair of the slots when the plug is coupled with the connector. The plug can be accurately coupled with the connector in the first or the second source voltage position based on a simple reading of the corresponding voltage indicator through the groove provided in the cover.

Abstract: A variable transformer, reactor having a core combining at least two complete core elements wiht a common yoke; primary winding divided into two independently fed sets of phase coils wound in opposite direction, arranged on symmetrical legs of core elements and separated by the common yoke; secondary winding with each phase coil divided into two wound in opposite direction portions carried by symmetrical core legs, adjacent to the primary coils and separated by common yoke. The secondary short-circuited reactor winding is reduced to at least one close loop member with loop portions separated by the common yoke. The single, polyphase apparatus has at least one primary coil per set that includes a controllable device in circuit relation therewith to enable control of one primary coil relative to the other, either in current magntidue or in current phase shift. The controllable device being either a silicon control rectifier, triac or transistor.

Abstract: A discharge lamp operating device having a high frequency inverter is discharged. Connected to a secondary winding of an oscillation transformer of the high frequency inverter is a discharge current supply circuit having a switch for controlling supply of a discharge current to dim a fluorescent lamp. An electrode heating circuit is connected to secondary windings of the transformer to continuously heat electrodes. An oscillation frequency of the inverter is controlled such that it increases as a dimming factor is high and decreases as the dimming factor is low. A capacitor is connected in series with a path of an electrode heating current in the electrode heating circuit so that the heating current is increased when the dimming factor is high and decreased when it is low by utilizing a frequency dependency of an impedance of the capacitor.

Abstract: An electric transformer for supplying an adjustable electric magnitude, especially for regulating purposes, includes several modules having therebetween a binary progression relationship with respect to their power handling capabilities. Each module has a switching network for selectively rendering it operative or inoperative and, each module has at least one primary circuit input coil, the primary coils of each of the modules cooperating with one single secondary output circuit which is common to all of the modules. The switching network of each module being so connected as to allow the neutralization of the effect of the electronic induction of its respective primary coil or coils on the common secondary circuit, while maintaining the magnetic activity of the primary circuits.

Abstract: A flat matrix transformer or inductor is made of a plurality of interdependant magnetic circuits, arranged in a matrix, between and among which electrical conductors are interwired, the whole cooperating to behave as a transformer or inductor. The flat matrix transformer or inductor has several advantageous features, among them compact size, good heat dissipation and high current capability. A flat matrix transformer or inductor can be very flat indeed, nearly planar, and can be built using printed circuit board techniques. A flat matrix transformer can insure current sharing between parallel power sources, and/or between parallel loads. The flat matrix transformer can be configured to have a variable equivalent turns ratio.

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.

Abstract: An apparatus for reducing the voltage applied to a load in an AC system utilizes an autotransformer and a relay or equivalent switching device between the common winding and the series winding. In each of the AC lines, the common winding and relay are connected between the load and the AC common while the series winding is connected between the input and the output. The relay is normally open to pass substantially full input voltage to the load, but when closed the relay permits current flow in the common winding to reduce voltage to the load. The relay or equivalent switching is therefore not in the direct flow of load current and can be of lower current rating and smaller size and cost as compared to prior art voltage reduction systems.

Abstract: A generally figure-of-eight transformer core carries first, second and third toroidal windings spaced along its central leg and is formed with magnetic shunts across the gaps between central and outside legs in the planes between windings. A capacitor is connected across the second winding of value so that it coacts with the effective leakage reactances provided by the magnetic shunts so that the output load current provided by the third winding is directly proportional to the input voltage applied across the first winding independently of the load impedance and with low distortion, even in the presence of high harmonic content in the input voltage and a nonlinear load impedance.

Abstract: A power control circuit is disclosed which may comprise a transformer having a primary winding and at least one secondary winding, a first and a second series circuit, and a rectifier circuit. The first series circuit may include a first DC power source, a first transistor and the primary winding of the transformer. The second series circuit may include the primary winding of the transformer, an excitation coil arranged to flow through the primary winding of the transformer a current which increases with time, a second DC power source and a second transistor. The rectifier circuit may be connected with the secondary winding of the transformer. In this power control circuit, an excitation current is first caused to flow through the primary winding of the transformer so that energy is stored therein.

Abstract: A method to control the welding transformer residual magnetizing current which normally continues circulating in the secondary circuit at the end of each welding pulse until the tips are opened. By utilizing a firing delay of the last half cycle in each welding pulse that brings the algebraic sum of the volt-seconds applied to the transformer to zero at the end of each welding pulse, the residual secondary current is nulled. This alleviates magnetizing current problems which occur in multiple pulse welding.