Abstract: A tapered ferrite core having a solid or hollow cylindrical shape with larger length than outer diameter, and comprising a ground taper portion in at least one end portion, the taper portion having ground streaks extending in the longitudinal direction of the ferrite core, can be formed by centerless-grinding a rotating ferrite core by a rotating grinder.

Abstract: A gatedriver circuit for controlling a power electronic switch. The circuit provides a galvanic separation and is magnetically immune. The gatedriver circuit comprises a transformer arranged with two separate cores of magnetically conductive material each forming a closed loop. A first electrical conductor has windings around a part of both cores, and a second electrical conductor also has windings around part of both cores. The two cores are positioned close to each other to allow mutual magnetic interaction. The windings of the first and second electrical conductors around the first core have the same winding direction, and the windings of the first and second electrical conductors around the second core have opposite winding direction of the windings of the first and second electrical conductors around the first core, so as to counteract electric influence induced by a common magnetic field through the closed loops of the first and second cores.

Abstract: An integrated common mode and differential mode inductor can include a first core including a first center leg, a second core including a second center leg, a first center winding on the first center leg, and a second center winding on the second center leg. The first center leg can be spaced apart from the second center leg, for example by a center air gap. The integrated common mode and differential mode inductor can further include a left winding on a first left leg of the first core and a second left leg of the second core, as well as a right winding on a first right leg of the first core and a second right leg of the second core.

Abstract: A flexible electrical current sensor is provided, the flexible electrical current sensor comprising a solenoid disposed about an at least partially magnetic core. The at least partially magnetic core comprises at least one magnetic element. The at least one magnetic element is configured to provide one or more regions of overlap such that a respective gap is provided in each region of overlap. Each respective gap is configured such that the effective magnetic permeability of the at least partially magnetic core is maintained during flexing.

Abstract: In one aspect, a method for over-voltage protection is provided. The method includes connecting a first winding of a saturable reactor to a direct current (DC) source; connecting at least one phase of an alternating current (AC) electrical system to ground through a second winding of the saturable reactor; and controlling DC current flow from the DC source to the first winding of the saturable reactor in response to an over-voltage event, wherein energy is shunted to ground from the at least one phase of the alternating current electrical system through the second winding of the saturable reactor.

Abstract: The present invention relates to a conventional circuit connected with the direct-current (DC) power supply in series through the semiconductor forward voltage drop, for producing voltage drop to lower the output DC voltage, however, if the output current is smaller, the voltage drop produced is not enough, the floating-voltage accordingly rises and damages the load, so a shunting current load is arranged in the circuit to suppress the floating-voltage.

Abstract: A voltage control circuit is disclosed. A power factor corrector may utilize the control circuit to provide power factor correction for an AC induction motor. An AC induction motor system may combine the power factor correct with an AC induction motor.

Abstract: The invention relates to a control circuit, in particular for a load in an automotive vehicle, comprising a chopping circuit, at least one LC filter (F1) means (20) opposing the saturation of the inductor, (L1) of this LC circuit, wherein these latter means (20) are provided so as to prebias the inductor in a chosen direction.

Abstract: A current limiting method and apparatus for preventing fault overload in a utility power transmission system employs a high power, superconducting coil based pulse transformer for saturating the core of the utility power transformer thereby limiting its current carrying capacity. The utility transformer core is biased to a disadvantageous portion of its B-H curve. A fault condition is detected and as a result the superconducting coil is quenched thereby sending a high energy pulse of current into the utility transformer magnetic core. The core, while heating, does not exceed its capability to maintain a stable thermal condition while at the same time limiting the current being transformed from its input to output lines, until a transformer circuit breaker activates.

Abstract: A rotating flux transformer which includes a magnetic core having poloidal primary and secondary windings and toroidal primary and secondary windings. Quadrature flux is produced in the magnetic core by connecting one end of the poloidal primary winding to the center of the toroidal primary winding. The quadrature flux combines vectorially to produce a rotating induction vector in the magnetic core.

Abstract: A pulse forming network with distributed inductance and capacitance is diosed for use in a magnetic modulator. The magnetic modulator has a magnetic core with a primary winding and a secondary winding around it. The pulse forming network includes an inner winding of flattened wire around the magnetic core and connected to one end of the secondary winding for receiving an induced voltage. The pulse forming network also includes a metal foil shield around the inner winding, so that the induced voltage may be stored capacitively between the inner winding and the shield. When the magnetic core saturates, the impedance of the secondary winding drops, so that the pulse forming network discharges through a load. The shape of the pulse through the load is determined by the inductance of the inner winding and the capacitance between the inner winding and the shield.

Abstract: A self-oscillating inverter circuit wherein the inversion frequency can be controlled by way of providing a controllable flow of electrical power to a resistor heating means that is thermally coupled to a saturable magnetic ferrite transformer used in the inverter's positive feedback loop. By way of its saturation characteristics, the saturable transformer determines the inversion frequency. These saturation characteristics are substantially influenced by temperature; which therefore provides the basis for controlling the frequency by controlling the flow of electrical power to the resistor heating means.

Abstract: A plurality of zones of an induction heating coil are individually controlled by varying the current through one or more zones of the coil to obtain a desired temperature profile in a workpiece. The current flow through a zone of the coil is determined by the conduction state of an associated saturable reactor, which is controlled in accordance with a preselected value or a variable value generated, for example, by a computer.