A power controller for an AC power converter connected in series with a load and receiving power from or delivering power to a power source, the power controller comprising: a radial control block controlling a radial component of an electrical parameter of the AC power converter; and a chordal control block controlling a chordal component of the electrical parameter of the AC power converter. Also provided is a power system comprising one or more loads each connected in series to a power converter each controlled by a power controller as described above. There is also provided a method of controlling an AC power converter connected in series with a load and receiving power from a power source, the method comprising: controlling a radial component of an electrical parameter of the AC power converter; and controlling a chordal component of the electrical parameter of the AC power converter.

An electrical load controller includes an electrical switching device and an actuator assembly having at least one user actuator for use in turning power on and off to the load and for use in adjustably controlling the level of power to the load. A frame attached to the actuator includes an integrally formed backlightable indicator region having an outer continuous solid surface. Light from an illumination assembly related to the level of power to the load is directable onto a portion of an inner surface of the backlightable indicator region, transmittable through the backlightable region from the inner surface to the outer surface, emittable from a portion of the outer surface, and observable by the user.

An electrical load controller includes an electrical switching device and an actuator assembly having at least one user actuator for use in turning power on and off to the load and for use in adjustably controlling the level of power to the load. A frame attached to the actuator includes an integrally formed backlightable indicator region having an outer continuous solid surface. Light from an illumination assembly related to the level of power to the load is directable onto a portion of an inner surface of the backlightable indicator region, transmittable through the backlightable region from the inner surface to the outer surface, emittable from a portion of the outer surface, and observable by the user.

A power supply apparatus includes a first circuit, a second circuit, an adjustment unit, a detection unit configured to detect a parameter, a first communication unit, a second communication unit configured to perform wireless communication with the first communication unit, and a control unit configured to control the adjustment unit, the detection result being transmitted from the first communication unit to the second communication unit by the wireless communication. The detection unit operates with power resulting from a voltage output from the control unit to the second communication unit. The first communication unit includes first wiring, the second communication unit includes second wiring, and the first wiring is disposed to not contact the second wiring. At least a part of a region surrounded by the first wiring and the detection unit overlaps a region surrounded by the second wiring and the control unit.

A power supply apparatus includes a first circuit, a second circuit, an adjustment unit, a detection unit configured to detect a parameter, a first communication unit, a second communication unit configured to perform wireless communication with the first communication unit, and a control unit configured to control the adjustment unit, the detection result being transmitted from the first communication unit to the second communication unit by the wireless communication. The detection unit operates with power resulting from a voltage output from the control unit to the second communication unit. The first communication unit includes first wiring, the second communication unit includes second wiring, and the first wiring is disposed to not contact the second wiring. At least a part of a region surrounded by the first wiring and the detection unit overlaps a region surrounded by the second wiring and the control unit.

A system includes conductive windings extending around a magnetic core and impedance-varying windings extending around the magnetic core. The impedance-varying windings include positive windings and negative windings. The conductive windings and the impedance-varying windings conduct electric current around the magnetic core. The system includes a first impedance tap changer that is electrically coupled with the positive windings of the impedance-varying windings and a second impedance tap changer electrically coupled with the negative windings of the impedance-varying windings. A controller controls the first impedance tap changer and the second impedance tap changer to change an impedance of the system by changing which portion of the positive windings and which portion of the negative windings are conductively coupled with the conductive windings, and which portion of the positive windings and which portion of the negative windings are disconnected from the conductive windings.

Power to an electrical device is controlled using a phase control that changes a cutoff phase of an alternating current (AC) electrical signal delivered to the electrical device. The power delivered to the electrical device is increased to an operational level using the phase control. A level of the power delivered to the electrical device is maintained at the operational level using an integral half cycle control that selectively removes a plurality of half cycles from the AC electrical signal delivered to the electrical device such that a plurality of remaining half cycles in the AC electrical signal delivered to the electrical device have a frequency outside a range of sub-harmonic frequencies.

Controlling power delivered to a heating device occurs using a phase control, wherein the phase control includes changing a cut-off phase of an alternating current electrical signal delivered to the heating device. The power delivered to the heating device is increased from zero to an operational level using the phase control. The level of the power delivered to the heating device is maintained at the operational level using both the phase control and an integral half cycle control. The integral half cycle includes selectively removing a plurality of half cycles from the alternating current electrical signal delivered to the heating device.

A two-wire load control device (such as, a dimmer switch) for controlling the amount of power delivered from an AC power source to an electrical load (such as, a high-efficiency lighting load) includes a thyristor coupled between the source and the load, a gate coupling circuit coupled between a first main load terminal and the gate of the thyristor, and a control circuit coupled to a control input of the gate coupling circuit. The control circuit generates a drive voltage for causing the gate coupling circuit to conduct a gate current to thus render the thyristor conductive at a firing time during a half cycle of the AC power source, and to allow the gate coupling circuit to conduct the gate current at any time from the firing time through approximately the remainder of the half cycle, where the gate coupling circuit conducts approximately no net average current to render and maintain the thyristor conductive.

Controlling power delivered to a heating device occurs using a phase control, wherein the phase control includes changing a cut-off phase of an alternating current electrical signal delivered to the heating device. The power delivered to the heating device is increased from zero to an operational level using the phase control. The level of the power delivered to the heating device is maintained at the operational level using both the phase control and an integral half cycle control. The integral half cycle includes selectively removing a plurality of half cycles from the alternating current electrical signal delivered to the heating device.