Abstract: A current sensor is for determining the level of the current of a conductor of a low-voltage circuit. In an embodiment, it includes a current transformer including a magnetic core. The magnetic core is an annular core having a core inner diameter, a middle diameter and a core outer diameter. The annular core is wound with a secondary winding, including an inner opening with an inner diameter and an outer circumference with an outer diameter. The secondary winding supplies the circuit with electrical energy. The wound annular core is configured such that the difference between the middle diameter as the minuend and the inner diameter as the subtrahend is 0.5 to 0.6 times smaller than the difference between the outer diameter as the minuend and the inner diameter as the subtrahend, to achieve an optimum for supplying energy and determining the level of the current in connection with the circuit.

Abstract: A method monitors capacitor bushings for an AC mains. The mains has first-third phases, associated with first-third mains lines, capacitor bushings, and mains voltages. Each capacitor bushing has a conductor, surrounded by foil, connecting its mains line. The method includes: at a first instant, for each phase: a first reference voltage phasor is determined; and a foil voltage present between the respective foil and ground potential is detected and a corresponding first foil voltage phasor is determined; at a second instant, for each of the phases: a second reference voltage phasor is determined; the foil voltage is detected and a second foil voltage phasor is determined; for each capacitor bushing: a loss factor change is calculated based on the respective reference voltages and foil phasors and those of the adjacent capacitive bushing; and a monitoring signal is generated based on a comparison of the loss factor and a tolerance value.

Abstract: A combination of a conductor, such as a busbar, and a device for measuring the AC voltage in the conductor, which device includes: an insulation layer arranged on the conductor; a capacitor plate arranged on the insulation layer and configured to position the capacitor plate at a fixed distance from the conductor to form a first capacitor; a second capacitor arranged electrically between the capacitor plate and ground to provide a capacitive voltage divider with the first capacitor; and a voltage measurer for measuring the voltage at the capacitor plate, the voltage measurer including a frequency measurer for measuring the frequency of the voltage in the conductor and an AC voltage calculator for calculating the AC voltage in the conductor based on the capacities of the first and second capacitors, the measured voltage, and the measured frequency.

Abstract: The invention relates to a computer tomography installation having contactless data signal transmission. The device comprises at least one longitudinally slit coaxial conductor element (1), at least one high-frequency transmitting unit (3), which feeds into the conductor element (1) a high-frequency carrier signal modulated with a data signal to be transmitted, at least one longitudinally slit coaxial coupling conductor element (2), which is designed to receive the emitted modulated high-frequency carrier signal (21) from the near field of the conductor element (1), and at least one high-frequency receiving unit (4), which is electrically connected to the coupling conductor element (2) and is designed to extract the data signal from the received modulated high-frequency carrier signal, wherein the conductor element (1) and the coupling conductor element (2) are arranged in such a way that the conductor element and the coupling conductor element can be moved in relation to each other.

Abstract: A vehicle includes a power receiving portion that contactlessly receives electric power from a power transmitting portion provided outside the vehicle and includes a shield member that is arranged around the power receiving portion in the same plane as a plane in which the power receiving portion is arranged, wherein the shield member includes a first shield region having a high shielding function and a second shield region having a shielding function lower than that of the first shield region at a position around the power receiving portion.

Abstract: A coil component capable of increasing normal mode impedance while maintaining common mode impedance is provided. The coil component includes a toroidal core, a first coil conductor and a second coil conductor wound around the toroidal core, and a ferrite bead attached to at least one coil conductor of the first coil conductor and the second coil conductor.

Abstract: A power converter is provided with a totem-pole power factor correction (PFC) circuit for bridgeless line rectification, and current sensing circuit that can be selectively disabled to reduce unwanted current sense signal components and undesirable current transformer voltage stresses. The totem-pole PFC has at least a first leg with first and second switching elements coupled in series. A PFC inductor is coupled between an AC input on a first end and a node between the switching elements. The current sensing circuit includes a first transformer winding coupled in series with the first switching element, a second transformer winding magnetically coupled to the first winding and configured to deliver current from the first winding to a current sense terminal during an active phase for the first switching element, and a shunt circuit configured to disable the current sensing circuit during a freewheeling phase for the first switching element.

Abstract: Electrical current transducer to measure the current flowing in a primary conductor, the transducer including an outer casing, a magnetic core comprising a magnetic circuit gap, a magnetic field detector comprising a sensing portion positioned in the magnetic circuit gap, an insulating core housing, a secondary coil formed from a wire wound around a coil support portion of the insulating core housing, and an electrostatic shield. The electrostatic shield is positioned between secondary coil and a radially inner wall portion of the outer casing, the radially inner wall portion defining a passage configured to receive said primary conductor therethrough. The electrostatic shield comprises a skirt portion formed by a plurality of flexible strips extending axially from an edge of the shield, the flexible strips configured to elastically bias against a base wall portion of the outer casing.

Abstract: A converter comprises a switch network coupled to a power source, wherein the switch network comprises a plurality of power switches, a magnetic device coupled to the switch network, a detector coupled to the magnetic device through a magnetic coupling and a control circuit configured to receive a zero voltage switching signal from the detector and adjust gate drive signals of the power switches based upon the zero voltage switching signal.

Abstract: An active switching rectifier circuit uses a MOSFET and applies a current based control to turn the MOSFET on and off. The MOSFET has its source and drain connected between an AC phase or neutral line and the DC output. A current detection and control circuit has an input current conductor coupled in series with the source-drain current of the MOSFET; it outputs a switching control signal based on the current in its input conductor and applies the signal to the gate of the MOSFET for on/off control. A Hall-effect switch may be used in the current detection and control circuit. The rectifier may also include a voltage supply circuit for supplying a DC voltage to the current detection and control circuit. The rectifier circuit can be adapted for various configurations including single-phase half-wave, center-tap dual-phase full-wave, single-phase full-wave, and three-phase full-wave.

Abstract: A device for harvesting energy from a power line carrying AC current including: a transformer having a core with separate first and second sections, the core being formed of ceramic material or layered nickel alloy tape; a first secondary winding wound around the first section of the core; a second secondary winding wound around the second section of the core; a first DC core-flux control winding wound around the first section of the core; and a second DC core-flux control winding wound around the second section of the core; wherein the core is configured to be in operative communication with a magnetic field radiated from the power line, such that an AC voltage is generated in the first and second secondary windings, and the maximum AC voltage produced by the first and second secondary windings is limited by the first and second DC core-flux control windings.

Abstract: An electrical current transducer comprising a housing, at least one magnetic core comprising an air gap and defining a central passage configured to receive a primary conductor carrying a primary current to be measured through the central passage, a magnetic field detector positioned at least partially in the air gap, and a grounding element. A lateral surface of the magnetic core is positioned against the grounding element without direct fixed attachment between the magnetic core and the grounding element, and the grounding element overlaps the magnetic core to an extent configured to ensure that a capacitive coupling (C3) between the magnetic core and the grounding element is greater than a capacitive coupling (C2) between the magnetic core and the magnetic field detector.

Abstract: A sensor assembly for measuring an intensity of a current includes a first sensor apparatus configured to record an intensity of the electrical current with contact, a second sensor apparatus configured to record an intensity of the electrical current, the second sensor apparatus having a common measurement range with the first sensor apparatus, and a first analog-digital converter configured to convert analog measured values into digitized measured values. The first sensor apparatus, the second sensor apparatus and the first analog-digital converter are arranged on a common circuit carrier.

Abstract: A high voltage power source device includes piezoelectric transformers, each of the piezoelectric transformers being formed with a primary electrode and a secondary electrode on piezoelectric ceramics, receiving a primary voltage at the primary electrode, and generating a second voltage from the secondary electrode, switching elements, each of the switching elements driving a respective one of the piezoelectric transformers, and primary voltage supply devices, each of the primary voltage supply devices supplying the primary voltage to the primary electrode of the respective one of the piezoelectric transformers by driving the respective one of the switching elements when the secondary voltage is generated from the respective one of the second electrodes, wherein the respective one of the primary voltage supply devices supplies the primary voltage to the respective one of the primary electrodes by driving the respective one of the switching elements at the same frequency.

Abstract: An apparatus is provided for securing to and collecting power from an electrical conductor including a wire clamp that clamps to and secures the apparatus to the electrical conductor, a current transformer (“CT”) that clamps to the electrical conductor and collects power from the electrical conductor, and a housing including a cavity that encloses circuitry associated with the apparatus. According to various aspects, the circuitry may include one or more sensors and wireless communications circuitry, and the CT may include a core and an electrical winding that receives an induced current from magnetic flux generated according to alternating current present on the electrical conductor.

Abstract: A method for processing output from a current transformer comprising deriving signal data from the output; converting the signal data from analog to digital format; removing a carrier signal from the signal data; squaring the signal data; and performing a recursive RMS algorithm on the signal data.

Abstract: A power supply device is disclosed for use in electronic equipment. In an embodiment, the power supply device includes: a current transformer with N secondary winding parts connected in series, an energy storage capacitor and a winding selector, in which N is an integral number and N?2, wherein the winding selector selectively enables one or more serially connected winding parts of the N secondary winding parts to output an electrical current, in response to a state signal indicating the operating state of the electronic equipment; and the energy storage capacitor is charged by the output current, and supplies power to a main circuit of the electronic equipment. In the embodiments of the present invention, there is also provided corresponding electronic equipment and a corresponding method. By way of the embodiments of the present invention, it is possible to supply electrical energy at relatively low power loss.

Abstract: A single-coil, toroid-type current transformer circuit for detecting both AC and DC current. The current transformer circuit may include a current transformer and an oscillator electrically connected to the current transformer. The current transformer circuit may further include an open and short CT detection circuit electrically connected to the oscillator for facilitating determination of the connection and stability state of the current transformer. A processor may be electrically connected to an output of the open and short CT detection circuit for performing a series of operations on signal data generated by the open and short CT detection circuit and manipulating the operation of an electrical power system accordingly.

Abstract: Power monitoring devices, a converter therefor that may be installed in the field, and a kit comprising such a power monitoring device and a converter are disclosed herein. The power monitoring devices may include a housing enclosing circuitry having one or more processors to monitor parameters of a power system and having a plurality of conduits passing therethrough and an electrically conducting plate mounted in the housing in contact with each of the conduits to electrically ground the conduits. The power monitoring device may also include a class two input terminal block for powering the circuitry and a plurality of wires connected thereto that extend out of the housing through such that the device, before installation in the field, can be pre-configured.

Abstract: In one embodiment, a current transducer is provided. The current transducer includes a magnetic core configured to at least partially encircle a magnetic flux generated by a conductor. At least one coil is coupled to the magnetic core and the magnetic core comprises a superm-alloy material.

Abstract: In a power converter, a reference signal generator generates a reference signal with a predetermined period. A current detector detects a current flowing in the converter. When a value of the detected current is larger than a value of a predetermined current command, a reset signal generator generates a reset signal. A driving unit drives a switch. The switch is turned on, and subsequently is turned off: (i) in synchronization with the reference signal when the reset signal is not outputted before the reference signal is outputted; and (ii) in synchronization with the reset signal when the reset signal is outputted before the reference signal is outputted. However, the switch is turned off in synchronization with the reset signal during a predetermined time including a first predetermined time before an output timing of the reference signal and a second predetermined time after the output timing of the reference signal.

Abstract: A combination converter arrangement and a switching device including such a combination converter arrangement are disclosed. The combination of a current transformer with a core made of ferromagnetic material and a Rogowski coil is referred to as a combination converter, the current transformer being used to supply energy to the electronic tripping unit of the switching device, and the Rogowski coil being used to measure current. In order to make use of the installation space available in the switching device for installing combination converters, a plurality of combination converters are arranged in a common housing to thereby provide a multi-pole combination converter module.

Abstract: A power supply device is disclosed for use in electronic equipment. In an embodiment, the power supply device includes: a current transformer with N secondary winding parts connected in series, an energy storage capacitor and a winding selector, in which N is an integral number and N?2, wherein the winding selector selectively enables one or more serially connected winding parts of the N secondary winding parts to output an electrical current, in response to a state signal indicating the operating state of the electronic equipment; and the energy storage capacitor is charged by the output current, and supplies power to a main circuit of the electronic equipment. In the embodiments of the present invention, there is also provided corresponding electronic equipment and a corresponding method. By way of the embodiments of the present invention, it is possible to supply electrical energy at relatively low power loss.

Abstract: A single-coil, toroid-type current transformer circuit for detecting both AC and DC current. The current transformer circuit may include a current transformer and an oscillator electrically connected to the current transformer. The current transformer circuit may further include an open and short CT detection circuit electrically connected to the oscillator for facilitating determination of the connection and stability state of the current transformer. A processor may be electrically connected to an output of the open and short CT detection circuit for performing a series of operations on signal data generated by the open and short CT detection circuit and manipulating the operation of an electrical power system accordingly.

Abstract: A power conversion circuit for decentralizing input current includes a capacitor, a first inductor, a first switching circuit, a first discharging circuit, a second inductor, a second switching circuit, a second discharging circuit, and a control circuit. Under control of the control circuit, the first switching circuit and the second switching circuit are alternately conducted, and the second switching circuit is successively conducted when the first switching circuit is shut off.

Abstract: A partial discharge analysis (PDA) coupling device is provided. In one embodiment, a device includes: a connector electrically connecting a first coupling capacitor and a second coupling capacitor; a first conductive rod for electrically connecting the first coupling capacitor to a high voltage input; a second conductive rod for electrically connecting the second coupling capacitor to ground; a current transformer substantially surrounding a portion of the second conductive rod, the current transformer configured to generate a pulse signal; and a reference signal generator adjacent to the current transformer configured to generate a reference signal in phase with the pulse signal.

Abstract: An electronic current transformer (ECT) based on complete self-excitation power supply is provided. The ECT includes an energy-obtaining coil, a rapid voltage-stabilizing circuit and an Analog/Digital (A/D) converting circuit. The output of the energy-obtaining coil is connected with the input of the voltage-stabilizing circuit. The output of the voltage-stabilizing circuit is connected with the control end of the A/D converting circuit. The ECT uses two branch circuits to obtain energy directly from the magnetic field of a bus bar to be measured respectively, synthesizes two output waveforms to fill the wave trough of each other, and reduces the pulse of direct current. In this way, the trough voltage of the synthesized wave is higher than the required stabilizing value of direct voltage and it directly meets the input requirement of the stabilizing module of the voltage-stabilizing circuit. As a result, the ECT can activate the A/D converting circuit rapidly.

Abstract: In a power supply arrangement for supplying electrical power to the pipeline, the power supply arrangement for direct electrical heating of a pipeline system has basically a three phase transformer, a symmetrization unit, and a compensation unit. The three phase transformer is adapted to support a single phase load connected between a first and a second phase of the transformer. The transformer has at least one first tap changer at a high voltage side of the transformer. The symmetrization unit has a first capacitor connected between the first phase and a third phase of the transformer and an inductor connected between the second phase and the third phase of the transformer. The compensation unit has a second capacitor connected between the first phase and the second phase of the transformer. The first tap changer, the first capacitor, the second capacitor and the inductor are adapted to be varied on-load.

Abstract: The present invention provides an inductive power supply for producing well-regulated noise-free supply of power suitable for sensitive equipment from a power transmission line. In an embodiment of the invention, the inductive power supply can be easily and safely attached to a high voltage transmission line for retrieving low voltage, AC or DC power. The inductive power supply utilizes an inductor, which is also known as a current transformer, to retrieve power from the transmission line. Energy storage components such as super capacitors may be optionally employed to store energy for later use. The electrical output of the power supply is a regulated low voltage output to power a load, e.g., sensitive electronics such as wireless devices and other microelectronics. The power supply further includes a sealed compartment for housing various types of low power devices coupled to the regulated low voltage output.

Abstract: The invention discloses a dummy battery apparatus (30), configured for supplying power to a portable electronic device (10). The portable electronic device (10) has a circuit board (13), which sets at least one testing port (130). The dummy battery apparatus (30) defines at least one gap thereon, and the defining place of the gap is corresponding to the location of the testing port (130) of the circuit board (13).

Abstract: There is provided an isolated power converter. More particularly, in one embodiment, there is provided a power converter including a first magnetic core having a primary winding and a secondary winding around the first magnetic core. The power converter also includes a second magnetic core having a first leg, a second leg coupled to the first leg, and a third leg coupled to the first and second legs, wherein a part of the third leg is equidistant from the first leg and the second leg. The power converter also has a first winding encircling the first leg, a first end of the first winding coupled to the secondary winding, a second winding encircling the second leg, a first end of the second winding coupled to the secondary winding, and a third winding encircling the third leg, a first end of the third winding coupled to a second end of the first wining and to a second end of the second winding.

Abstract: A system for transmitting data and/or energy between a chassis and a seat that is movably arranged on the chassis, the seat being able to glide with the aid of slides in guide rails attached to the chassis; one iron-core half of a transformer, the iron-core half bearing at least one primary winding is positioned on the slide gliding in the guide rail, the primary winding being a cable in the guide rail; and the other iron-core half of the transformer, having a secondary winding, is positioned on the seat, the two limbs of the other iron-core half being arranged in the longitudinal direction with respect to the guide rail, and both iron-core halves of the transformer being positioned relative to each other for the data and/or energy transmission.

Abstract: A capacitive voltage transformers for distribution of the power from 10 kv high potential line, includes a insulating column with a high potential terminal, a ground terminal and capacitors C1 and C2 in series connection. The column is filled with oilless dry filler. The capacitors C1 and C2 formed by a plurality of separated metallized film capacitors respectively in series or in parallel connection. At the tapping point between the capacitors there is a leading-out terminal of the secondary voltage which is connected to an induction transformer L in parallel. The transformer includes a frame with “C” shaped iron cores and windings wound around the cores. There is an over-voltage protector P connected in parallel between the tapping point and ground. A capacitive voltage divider is integrally combined with the transformer to provide a small volume, low cost device with a savings in materials.

Abstract: A Swain type direct current clamp-on sensor called MER2 is disclosed with improved magnetic error reduction from undesired magnetic fields generated by noise sources for accurate measurement of low currents. The sensor is comprised of a split core with non uniform magnetic structure designed to concentrate the magnetomotive force generated by the current being measured, and also by the switching magnetomotive force, through the windings near the lips of the sensor for better signal to noise ratio. The sensor core has non-uniform windings with greater ampere-turns near the lips than in other sectors of core remote from the lips so that the flux density of magnetic material in and near the lips is better switched. Furthermore, there is a provision for combining and adjusting current signals such that the noise is largely canceled. A method of making the direct current clamp-on MER2 is also disclosed.

Abstract: A dual-rated current transformer circuit has a first circuit which delivers a first current and a second circuit which delivers a second current. A current transformer is coupled to both the first and second circuits, wherein the transformer generates a current proportional to the current of each of the first and second currents.

Abstract: A current transformer for mains alternating current with dc components is formed of at least one transformer core with a primary winding and at least one secondary winding, of load resistor is connected in parallel to the secondary winding and terminates the secondary circuit in low-impedance fashion. A semiconductor component that opens during a suitable time span within every cycle and is in turn closed is provided in the secondary circuit. During this time span, the secondary circuit is in a no-load condition. As a result thereof, the build-up of the core magnetization generated by the dc components is collapsed, and thus the transformer core cannot be driven into saturation, so that an over-dimensioning of the transformer cores is unnecessary.

Abstract: A circuit for detecting peak current pulses on a secondary transformer of a power supply and converting these peak current pulses into a direct current (DC) voltages, which can be used for various purposes such as current limiting or current sharing. A peak detection circuit is coupled to the secondary transformer and is employed to detect a peak current pulse through the secondary transformer. A sample and hold circuit that is coupled to the peak detection circuit samples the current through a current sense transformer. The sample and hold circuit provides the current pulse through the secondary transformer in a direct current voltage representation. The sample and hold circuit includes a storage circuit for storing this direct current voltage representation of the current through the secondary transformer. The sample and hold circuit selectively samples the current through the current transformer in response to a control signal generated by the peak detection circuit.

Abstract: A circuit to maintain proper current transformer operation in a resonant transition converter circuit or any circuit having a wide range of reverse current present in a current transformer primary at the beginning of a power pulse. The circuit includes an active clamp which is applied to an extra secondary on the current transformer for the duration of a "on" time of a switch associated with a particular current transformer. A diode of the active clamp is polarized to accept current in the secondary when primary current is reversed or negative flow. Thereby only small amounts of voltage, and thus volt-seconds will be developed on the transformer during reverse primary current, in turn keeping the current transformer out of reverse saturation.

Abstract: In the case of the current transformer according to the invention, the components used are arranged in a novel manner. The primary winding (7) is arranged around the secondary winding (8), with an extended core (9), at a distance which is provided for the insertion of high-voltage insulation (10). The secondary winding (8) and core (9) are located in an earthed, electrically conductive tube (12) in which the output leads of the secondary winding are connected to earth. This construction results in the avoidance of the core and windings looping around one another, which is necessary according to the prior art, is unfavourable for some applications, and is costly in manufacture.

Abstract: A three-phase collected type optical current transformer having a common hermetically sealed container miniaturized in its radial direction. The common hermetically sealed container incorporating central conductors and optical current transformers corresponding to three phases has a branch tube or flange in its radial direction. The flange incorporates optical spacial transmission members for three phases which guide the signals sent from the optical current transformers through optical fibers to the exterior of the common hermetically container. The optical spatial transmission members are arranged collectively. The common hermetically sealed container, when it has a branching portion protruding in its radial direction at its end, incorporates no flange but a concentrated optical spacial transmission member for three phases at the end in the axial direction of the common hermetically sealed container having the branching member.

Abstract: In a flyback transformer having a focus pack, in order to facilitate the manufacture and assembly of the focus pack, the focus pack mounted on the flyback transformer is constituted by an outer case portion and an inner case portion, and the outer and inner case portions are coupled to each other by a coupling portion and integrally formed. The inner case portion contains a circuit board having a resistor circuit for setting a focus adjusting voltage and a screen adjusting voltage. A focus insertion hole and a screen insertion hole are formed in the coupling portion. A focus shaft for variably setting a focus adjusting voltage is rotatably fitted in the focus insertion hole. A screen shaft for variably setting a screen adjusting voltage is rotatably fitted in the screen insertion hole. An insulating casting resin is injected between the gaps between the outer and inner case portions.

Abstract: The present invention has an object to develop a converter allowing dielectric strength of a booster transformer to be reduced by half for miniaturization and security thereof. To achieve this object, the booster transformer is provided with first and second secondary coils so that, every time a switching element is turned ON, the first secondary coil generates positive voltage in reference with the negative terminal potential of a DC source while the second secondary coil generates negative voltage also in reference with the negative terminal potential of the DC source and a sum of these positive and negative voltages is output from the converter as a composite voltage.

Abstract: An arrangement is provided for accurately sensing the source voltage of a high-impedance source while supplying a variable burden. A current-sensing element is connected in series with a load circuit across a high-impedance source. The load circuit includes a variable burden load. A shunt regulator is connected with the variable burden load and is arranged to operate so that the combination of the shunt regulator and the variable burden present a controlled, nearly constant burden to the high-impedance source. The source voltage of the high-impedance source is sensed via the voltage across the series current-sensing element. While the output voltage is directly proportional to the burden, the output current is essentially unaffected by small variations in the burden.

Abstract: In a current transformer arrangement for three-wire three-phase systems, use is made of a single busing transformer (4) arranged on the three-phase side. Two of the total of three phase conductors are pushed through the bushing transformer, specifically either with the same number of turns per unit length and in mutually opposite defined directions or with the same direction and with the ratio of different numbers of turns per unit length of 2:1 or with the same direction and a current flow halved in a phase conductor by a shunt (15). These arrangements prevent the occurrence of a zero resultant magnetic flux. The double secondary voltage produced by a double AW value occurring twice during each period is halved by an electronic correcting circuit. The control commands are derived from suitable control pulses for the thyristors (21-26) of the three-phase bridge circuit (16). Two correcting circuits are specified.

Abstract: Electrical impedance matching for through plane connections or vias in a multiplane laminated wiring structure is provided by arranging the vias in patterns conforming to a standard characteristic impedance configuration. The pattern may be a five wire configuration with four vias surrounding the fifth and repeated over the area of the plane.

Abstract: In connection with an automatic starting feature for an auxiliary unit, preferably a vacuum cleaner, which is switched on simultaneously when a main unit, for example an electric hand tool, a machine tool, or the like, is started it is proposed to trigger a conventional (phase) control circuit provided for the auxiliary unit by means of a current sensor taking the form of a ring-core bushing transformer in a manner such that the electric motor of the auxiliary unit is switched on with a certain delay (smooth-starting feature). The ring-core bushing transformer is designed in such a manner that, for producing clear firing pulses for the triac of the auxiliary unit, the primary winding is formed by the one turn of the electric supply line of the main unit and passed through the central opening of the ring core.

Abstract: A circuit arrangement for providing a store of energy for actuating an electrically operable device, incorporating a reservoir capacitor, comprising a transformer having low resistance windings, the primary winding of which is connectable to an alternating current high voltage supply in series with at least one resistance capacitor, and the secondary winding of which is connected to the reservoir capacitor through a rectifier, the capacitor being connectable to an electrically operable device, with the turns ratio of the transformer such as to produce a secondary current of sufficient magnitude to charge the reservoir capacitor in the time available for successive operations or successive operational sequences of the device.

Abstract: A transimpedance circuit for generating an output voltage replica of an alternating current input has its accuracy improved by the use of a current comparator, the ratio windings of the comparator respectively carrying a current proportional to the input current and a current proportional to the output voltage. A further winding of the comparator detects any ampere-turns imbalance in the ratio windings, and, as a result, generates a correction signal proportional to such imbalance. This correction signal is then employed to correct the output voltage.

Abstract: An apparatus for recovering an alternating variable having a direct current component in a controlled semiconductor component includes an electromagnetic transducer for measurement having a secondary winding. A sample and hold element has a trigger input, an output and another input connected to the secondary winding of the transducer. A control system for the semiconductor component is connected to the trigger input for feeding trigger pulses from the control system to the trigger input at respective control times of the semiconductor component. A comparator has a first input connected to the output of the sample and hold element for receiving an output signal proportional to the direct current component, a second input connected to the secondary winding of the transducer and an output supplying the recovered alternating variable.

Abstract: To produce a high current carring inductor with a high inductance value in space normally too small, a transformer is chosen which meets space requirements and has a primary winding of sufficient current capacity, but too little inductance. A bidirectional current source drives the secondary winding under control of a feedback circuit in response to sensed primary winding current to effectively multiply the primary winding inductance.