The present invention discloses a lighting installation having an LED lamp (19), normally consisting of a series string of individual LED's (18), which is supplied by a rectifier (20, 200). A control circuit (23, 23 & C1) is interposed between the rectifier and the AC supply which powers the rectifier. Various circuits for filtering, power factor control, multi-phase operation and dimming, for example by phase switching, are disclosed. In particular, the control carried out by the control circuit takes place on the AC side of the rectifier. Also disclosed are the control circuit per se and a method of converting a High Intensity Discharge (HID) lamp installation into a Light Emitting Diode (LED) installation. The control circuit can take the form of an inductor, an inductor and series capacitor, a shunt inductor, a leakage reactance transformer, a constant current transformer, an autotransformer, an isolation transformer or a ferro-resonant transformer.

An inductor includes a first terminal and a second terminal, a first inductor conductor layer and a second inductor conductor layer, a magnetic core layer, and via conductors. The magnetic core layer is disposed between the first and second inductor conductor layers. The via conductors are connected to the first and second inductor conductor layers. The first and second terminals are electrically connected through the via conductors. The magnetic core layer includes a first magnetic substance portion including a first magnetic substance, and a second magnetic substance portion including a second magnetic substance. Magnetic properties of the second magnetic substance are different from magnetic properties of the first magnetic substance.

Differential-coil, high-voltage series reactors respond quickly and reliably to current surges in electrical power systems (such as surges caused by shorted or downed lines). The reactors prevent voltage collapse and eliminate the possibility of wide area blackouts (major metropolitan areas or entire states).

A boost converter may include a first stage comprising a first dual anti-wound inductor constructed such that its windings generate opposing magnetic fields in its magnetic core, and a second stage comprising a second dual anti-wound inductor constructed such that its windings generate opposing magnetic fields in its magnetic core. The boost converter may also include control circuitry for controlling the first stage and the second stage to have a plurality of phases comprising a first phase wherein a first coil of the first dual anti-wound inductor and a second coil of the second dual anti-wound inductor are coupled in parallel between a power supply and a ground voltage and a second phase wherein the first coil of the first dual anti-wound inductor and the second coil of the second dual anti-wound inductor are coupled in series between the power supply and the ground voltage.

A fault current limiter (FCL) includes at least one magnetisable core member and at least one AC magnetomotive force source configured to generate a varying magnetic flux in at least a portion of the at least one magnetisable core member. At least one static magnetomotive force source is positioned to provide a magnetic circuit within at least part of the at least one magnetisable core member and the AC magnetomotive force source and the static magnetomotive force source are relatively positioned to be orthogonal to each other. Typically the static magnetomotive force source may be a permanent magnet and the AC magnetomotive force source configured to generate a varying magnetic flux in both of first and second spaced core members.

The current transformer includes a magnetic circuit made of magnetic material that is intended to be placed around a primary conductor, and a secondary winding that is wound onto a portion of the magnetic circuit in order to deliver a secondary current to processing circuits. In this current transformer the magnetic circuit includes at least one device for varying the magnetization of a portion of the magnetic circuit according to the temperature in order to limit or to decrease the magnetic flux in the magnetic circuit when the temperature of the magnetic circuit increases. The protection device and the electrical circuit breaker include such a transformer.

A fault current limiter, including: two inductors, a direct current circuit breaker, a shunt resistor, a first fixed resistor, and metal oxide arresters. The two inductors include wound superconducting wires. The inductors have identical number of windings and identical structure. Magnetic fluxes of the inductors are forward coupled, and the inductors are connected in parallel to form a superconducting inductor structure. The direct current circuit breaker and the superconducting inductor structure are connected in series to form a series branch. The shunt resistor is connected in parallel to the series branch. The first fixed resistor is connected in parallel to the direct current circuit breaker. The metal oxide arresters are two in number, and are connected to two ends of the inductors in parallel.

A magnetic component has a variable inductance over a range of DC bias currents. The component includes a bobbin with a coil positioned around a passageway between first and second end flanges. First and second E-cores (either conventional or EFD E-cores) have respective middle legs positioned in the passageway with end surfaces of the middle legs juxtaposed within the passageway and spaced apart by a first magnetic gap. An I-bar is positioned in the passageway parallel to and spaced apart from respective first longitudinal surfaces of the middle legs to form a second magnetic gap between the I-bar and the longitudinal surface of the middle leg of the first E-core and to form a third magnetic gap between the I-bar and the longitudinal surface of the middle leg of the second E-core. The magnetic component provides higher inductances for lower bias currents and provides lower inductances for higher bias currents.

Techniques are provided for segmented windings of a coupled inductor within a DC-DC voltage converter or regulator. In an example, a coupled inductor circuit can include a first winding comprising a conductive coil having a central axis, and a second winding configured to magnetically couple with the first winding. The second winding can have a plurality of individual segments. Each individual segment can form a fraction of one turn of the second winding. Each segment can include a first conductor, a ground conductor, and a first switch to selectively couple, and selectively isolate, the first conductor and the ground conductor.

Differential-coil, high-voltage series reactors respond quickly and reliably to current surges in electrical power systems (such as surges caused by shorted or downed lines). The reactors prevent voltage collapse and eliminate the possibility of wide area blackouts (major metropolitan areas or entire states).