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 semiconductor switch control device includes a first FET and a second FET arranged adjacent to each other, in which source terminals are connected in series. A drain terminal of the first FET is connected to a high voltage battery, and a drain terminal of the second FET is connected to a high voltage load. A controller determines a temperature state of a minus-side main relay including the second FET based on a forward voltage of a body diode of the first FET.

A semiconductor switch control device includes a first FET and a second FET arranged adjacent to each other, in which source terminals are connected in series. A drain terminal of the first FET is connected to a high voltage battery, and a drain terminal of the second FET is connected to a high voltage load. A controller determines a temperature state of a minus-side main relay including the second FET based on a forward voltage of a body diode of the first FET.

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.

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.

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.

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 comprising two MOS-gated transistors, and a control circuit. The control circuit generates first and second drive voltages for individually controlling the MOS-gated transistors, and controls the gate coupling circuit to cause the MOS-gated transistors to conduct a pulse of current through a gate terminal of the thyristor to render the thyristor conductive at a firing time during a present half cycle of the AC power source, and to allow the MOS-gated transistors to conduct at least one other pulse of current through the gate terminal after the firing time during the present half cycle.

A constant-voltage drive device capable of adjusting output voltage includes a chopping wave structure, an AC power voltage detection module, an AC voltage signal bias module, a power factor correction controller with multiplier, a power factor correction and energy conversion and transmission module, an output control module, a reference signal generation module, an AC power phase angle detection module and a phase angle information transmission module. The output voltage can be both constant and adjustable, so that the output changes with the phase angle information of input, and also provides the chopping wave structure with current for proper functioning. The device is applicable for bigger power range with better compatibility and stronger adaptability.