A bidirectional switch switched to conduct and interrupt a bidirectional current between a pair of input terminals. An input device receives a dimming level representing a value of light output of the load. A controller controls the bidirectional switch according to the dimming level. The controller controls the bidirectional switch to keep the bidirectional switch in an off-state from a start point of a half cycle of the AC voltage of the AC power supply to a first time point when a first time period therefrom elapses, and to turn the bidirectional switch to an on-state at the first time point. The controller turns the bidirectional switch to the off-state at a second time point when a second time period elapses from the first time point. The controller keeps the bidirectional switch in the off-state from the second time point to an end point of the half cycle.

A configurable light sensor comprising an array of photocells. The light sensor measures ambient light reflected from a surface in area to be monitored. A lens directs the light onto the array of photocells. A microcontroller reads each individual photocell and processes the signals from the photocells according to one or more of the methods disclosed herein. The light sensor is configurable in that the area that monitored by the light sensor is customized to match the area lit by an associated light source. The configuring process defines an active area to be monitored, by determining which subset of photocells in the array, referred to as the active set of photocells, corresponds to the area being illuminated by the light fixture. The light sensor is subsequently able to monitor the defined active area and to report sensor output values based on measurements made from the photocells monitoring the active area.

A dimmable ballast circuit for a compact fluorescent lamp controls the intensity of a lamp tube in response to a phase-control voltage received from a dimmer switch. The ballast circuit comprises a phase-control-to-DC converter circuit that receives the phase-control voltage, which is characterized by a duty cycle defining a target intensity of the lamp tube, and generates a DC voltage representative of the duty cycle of the phase-control voltage. Changes in the duty cycle of the phase-control voltage that are below a threshold amount are filtered out by the converter circuit, while intentional changes in the duty cycle of the phase-control voltage are reflected in changes in the target intensity level and thereby the intensity level of the lamp tube.

A measurement assembly includes a first light emitter set including a plurality of light emitters arranged at equal intervals in a first direction, the light emitters emitting lights with frequencies different from one another; a light receiver disposed on an object under measurement and configured to receive incident lights from the light emitter set; and a position determination unit configured to determine a first current position of the object under measurement according to frequencies of incident lights currently received by the light receiver from the first light emitter set.

A dimmable ballast circuit for a compact fluorescent lamp controls the intensity of a lamp tube in response to a phase-control voltage received from a dimmer switch. The ballast circuit comprises a phase-control-to-DC converter circuit that receives the phase-control voltage, which is characterized by a duty cycle defining a target intensity of the lamp tube, and generates a DC voltage representative of the duty cycle of the phase-control voltage. Changes in the duty cycle of the phase-control voltage that are below a threshold amount are filtered out by the converter circuit, while intentional changes in the duty cycle of the phase-control voltage are reflected in changes in the target intensity level and thereby the intensity level of the lamp tube.

Disclosed is a driver that include a switching circuit for guiding current signal during time-intervals for the sequential driving of light emitting circuit. The time-intervals are defined by the fact that amplitudes of a mains signal are in ranges during the time-intervals. More specifically, there is a bypass switching circuit for guiding a bypass current signal which bypasses all light emitting circuit during an initial time-interval. An adaptation circuit adapts amplitudes of the respective current signals during the respective time-intervals, to reduce a total harmonic distortion. Said adapting may comprise an adaptation in response to information derived from the amplitude of the mains signal, and may comprise shaping the amplitudes of the current signals in response to information derived from the amplitude of the mains signal.

A light emission control device includes a power source circuit for a drive circuit that supplies a power for a drive circuit based on an input power, a power source circuit for a control circuit that supplies a power for a control circuit based on the input power, a control circuit, a drive circuit, and a start control circuit. The control circuit outputs a control signal for controlling turning on/off of a switching element. The drive circuit outputs a drive signal for driving the switching element based on the control signal. The start control circuit outputs a start control signal for delaying a timing at which the output of the drive signal is started after the input power is turned on.

This information processing method is executed by an electric light bulb light source apparatus, which includes a lighting unit, and a functional unit, the information processing method including: selecting, from any of a parent mode and a child mode, an operation mode for cooperative control with a different electric light bulb light source apparatus with respect to the functional unit, and setting the selected operation mode. In a case where the parent mode is set, the lighting unit is caused to execute a first lighting operation for the parent mode in response to a predetermined lighting control signal relating to an operation of the lighting unit, and a cooperative control signal for causing a second lighting operation for the child mode to be executed is transmitted to the different electric light bulb light source apparatus set to the child mode, the second lighting operation for the child mode being different from the first lighting operation. In a case where the child mode is set, the lighting unit is caused to execute the second lighting operation on the basis of the cooperative control signal transmitted from the different electric light bulb light source apparatus set to the parent mode.

The present invention generally relates to a method for operating a plurality of field emission light sources, specifically for performing a testing procedure in relation to a plurality of field emission light sources manufactured in a chip based fashion. The invention also relates to a corresponding testing system.

The present invention generally relates to a method for operating a plurality of field emission light sources, specifically for performing a testing procedure in relation to a plurality of field emission light sources manufactured in a chip based fashion. The invention also relates to a corresponding testing system.