Abstract: A circuit with a magnetically variable inductor that is placed in close proximity to an independently wound control coil and connected in parallel to a current transformer having primary and secondary windings wound on a magnetic core wherein the transformer core with associated windings. The inductor core is placed within the bore of the control coil and an optional focusing armature concentrates the magnetic field at the poles. Application of a control current forms poles at the control coil extremities and causes a change in magnetic properties of the inductor core thereby altering the power output of the current transformer inversely to the magnitude of the control current. The control current from the output of the secondary coil of a current transformer in series with the load and conditioned by a feedback conditioning circuit modulates the level of the control current. The magnetically variable inductor controls a D.C. to A.C.

Abstract: A circuit with a magnetically variable inductor that is placed in close proximity to an independently wound control coil and connected in parallel to a current transformer having primary and secondary windings wound on a magnetic core wherein the transformer core with associated windings. The inductor core is placed within the bore of the control coil and an optional focusing armature concentrates the magnetic field at the poles. Application of a control current forms poles at the control coil extremities and causes a change in magnetic properties of the inductor core thereby altering the power output of the current transformer inversely to the magnitude of the control current. The control current from the output of the secondary coil of a current transformer in series with the load and conditioned by a feedback conditioning circuit modulates the level of the control current. The magnetically variable inductor controls a D.C. to A.C.

Abstract: A circuit with a magnetically variable transformer having primary and secondary windings wound on a magnetic core wherein the transformer core with associated windings is placed in close proximity to an independently wound control coil. The transformer core is placed within the bore of the control coil and an optional focusing armature concentrates the magnetic field at the poles. Application of a control current forms poles at the control coil extremities and causes a change in permeability of the transformer core thereby altering the power output of the transformer inversely to the magnitude of the control current. The control current from the output of the secondary coil of a current transformer in series with the load and conditioned by a feedback conditioning circuit modulates the level of the control current. The magnetically variable transformer controls a D.C. to A.C. inverter circuit, which is useful in supplying power to a fluorescent lamp and other A.C. receptive loads.

Abstract: A variable inductor includes at most one coil of electrically conductive material and at most two distinct, separately formed portions of magnetic core material positioned to conduct magnetic flux resulting from passage of electrical current through the coil. At least one of the portions of magnetic core material is located at least partially within a space surrounded by the coil and is movable with respect to the coil. A control device is attached to the movable portion of magnetic core material in a manner such that the movable portion can be moved in its entirety, by manipulating the control device, to change the configuration of a gap within the space surrounded by the coil and defined in part by the movable portion, to vary thereby the inductance of the coil.

Abstract: A device for regulating the intensity of light emitted by a lamp includes a core of magnetic material, a first electrical circuit having a primary inductor wrapped around at least a portion of the core of magnetic material, and a second electrical circuit having a secondary inductor wrapped around at least a portion of the core of magnetic material. The first electrical circuit is designed for electrical connection to the lamp, and the primary inductor is arranged in the first electrical circuit in a manner such that a variation in the inductance of the primary inductor will cause a corresponding variation in the intensity of light emitted by the lamp. The second electrical circuit includes a control device (e.g.

Abstract: A device for regulating the intensity of light emitted by a lamp includes a variable inductor configured to surround a portion of the lamp and electrical circuitry arranged to connect electrically the variable inductor to the lamp in a manner such that a variation in the inductance of the variable inductor will cause a corresponding variation in the intensity of light emitted by the lamp while the lamp is electrically connected to the variable inductor.

Abstract: A control circuit is disclosed that can be used to control the light intensity of a fluorescent lamp. A first embodiment of the control circuit includes one variable inductor and a plurality of fixed inductors. A switch is used to connect one of the inductors to the fluorescent lamp in parallel. The intensity of the light output from the lamp is varied either by adjusting the inductance of the variable inductor, or by switching between the fixed inductors. A second embodiment uses a variable capacitor in place of the variable inductor and uses fixed capacitors in place of the fixed inductors.