An illumination device and method are provided for controlling light emitting diodes (LEDs). The LEDs (specifically, the LED loads) are controlled, e.g., brightness and color of the LED loads, independent of a phase-cut dimmer applied to the AC mains feeding a DC power supply. The power supply is active dependent upon the duration of a conduction angle supplied from the dimmer. The power supply, however, produces drive currents that are independent from the conduction angle by using a two-stage power supply and a relatively slow and fast control loops that are controlled through a microprocessor based control circuit. Parameters stored in the control circuit are drawn by the microprocessor to control the two-stage power supply to produce the drive currents independent and decoupled from the conduction angle yet dependent on the controller parameters.

A method of controlling at least one switching module having commutation cells which are associated with a regulating winding of a regulating transformer, the commutation cells including: a first and second switching element each having two thyristors in antiparallel connection.

A processor-based device includes a chassis having a chassis ground node that is arranged to electrically couple the chassis to an earth ground. The device also includes a connector accessible from an exterior of the chassis. The connector conforms to a standardized powerline interface having a hot power signal, a load power signal, and a neutral power signal. A processor-based apparatus housed at least in part within the chassis is arranged to operate using DC power derived from AC power present at the powerline interface. A stray voltage detector is arranged to detect a stray voltage potential existing between the neutral power signal of the standardized powerline interface and the chassis ground node, and the processor-based device is arranged to communicate at least one indication of the detected stray voltage potential.

An apparatus for an alpha trim adjustment includes a phase delay circuit that creates a phase delay for a gate signal for a switching cycle. The gate signal is for a phase of a three-phase, phase shifted alternating current (AC) input of a multi-pulse motor drive powering a direct current (DC) motor. The apparatus includes an alpha trim circuit that modifies the phase delay with an alpha trim adjustment to create an adjusted phase delay for the switching cycle, a delay application circuit that applies the adjusted phase delay to the gate signal.

A load control device for controlling power delivered from an alternating-current power source to an electrical load may comprise a controllably conductive device, a control circuit, and an overcurrent protection circuit that is configured to be disabled when the controllably conductive device is non-conductive. The control circuit may be configured to control the controllably conductive device to be non-conductive at the beginning of each half-cycle of the AC power source and to render the controllably conductive device conductive at a firing time during each half-cycle (e.g., using a forward phase-control dimming technique). The overcurrent protection circuit may be configured to render the controllably conductive device non-conductive in the event of an overcurrent condition in the controllably conductive device. The overcurrent protection circuit may be disabled when the controllably conductive device is non-conductive and enabled after the firing time when the controllably conductive device is rendered conductive during each half-cycle.

A method of controlling at least one switching module having commutation cells which are associated with a regulating winding of a regulating transformer, the commutation cells including: a first and second switching element each having two thyristors in antiparallel connection.

An inverter anti-islanding control system includes a phase-shift loop (10) and a drive circuit (20). The phase-shift loop (10) includes a first input end (11), a second input end (12), a third input end (13), a fourth input end (14), a first output end (15), and a second output end (16). The drive circuit (20) includes a first input end (21), a second input end (22), a third input end (23), and an output end (24). The first output end (15) of the phase-shift loop (10) is connected to the first input end (21) of the drive circuit (20), and the second output end (16) of the phase-shift loop (10) is connected to the second input end (22) of the drive circuit (20). In the inverter anti-islanding control system, when an inverter is in an island state, a frequency of an inverter alternating current end voltage is deviated to a second frequency by using the phase-shift loop (10), so that the second frequency triggers frequency protection to disconnect the inverter from an electrical network, to be specific, the inverter is out of the island state.

A phase controlled power regulation circuit is isolated from a line voltage and therefore overcomes some of the safety issues associated with currently available potentiometers. A phase controlled power regulation circuit employs a potentiometer that is electrically isolated from mains power. A transformer regulates the line voltage down to a reduced reference voltage that is used by the power regulation circuit. Any single point failure of a component within the power regulation circuit will not create unsafe condition. This greatly simplifies regulatory approval and opens new applications. Since the potentiometer is operated at low voltage, it may be remotely located from the circuits that handle the power with two conductors of class 2 wiring. Also, the potentiometer need not be of a panel mounted rotary or sliding type. It may be a potentiometer integrated circuit controllable from a microprocessor that enables complex regulation and/or sequencing control.

A load control device for controlling the power delivered from an AC power source to an electrical load includes a thyristor, a gate coupling circuit for conducting a gate current through a gate of the thyristor, and a control circuit for controlling the gate coupling circuit to conduct the gate current through a first current path to render the thyristor conductive at a firing time during a half cycle. The gate coupling circuit is able to conduct the gate current through the first current path again after the firing time, but the gate current is not able to be conducted through the gate from a transition time before the end of the half-cycle until approximately the end of the half-cycle. The load current is able to be conducted through a second current path to the electrical load after the transition time until approximately the end of the half-cycle.

A method and device is disclosed for charging and/or maintenance of lead-acid and alkaline accumulator batteries, allowing a charge, discharge, or recovery in control-conditioning cycles of these batteries. To increase efficiency of the battery recovery process, its charge is created by a reversible current in consecutive stages. Correction of the charging mode is provided based on voltage and temperature of the accumulator battery.