Disclosed are a filament device for an illumination device, the illumination device, and a dimming method for the illumination device. The illumination device comprises: a dimming unit electrically connected to an external power supply, a first illumination unit which is electrically connected to the dimming unit and to which an input voltage from the external power supply is applied, a second illumination unit which is electrically connected to the dimming unit and to which an input voltage from the external power supply is applied, a unidirectional conduction unit electrically connected to the first illumination unit and the second illumination unit, a first current-limiting unit electrically connected to the first illumination unit; and a second current-limiting unit electrically connected to the second illumination unit, wherein the amplitude of the input voltage varies on the basis of a phase-cut angle of the dimming unit, when the amplitude of the input voltage varied on the basis of the phase-cut angle satisfies a first predetermined condition, the unidirectional conduction unit is in a turn-on state, and the illumination device operated in a first operation mode; and when the amplitude of the input voltage varied on the basis of the phase-cut angle satisfies a second predetermined condition, the unidirectional conduction unit is in a turn-off state, and the illumination device operates in a second operation mode. The effect of deepening the dimming depth is achieved.

Disclosed are a filament device for an illumination device, the illumination device, and a dimming method for the illumination device. The illumination device comprises: a dimming unit electrically connected to an external power supply, a first illumination unit which is electrically connected to the dimming unit and to which an input voltage from the external power supply is applied, a second illumination unit which is electrically connected to the dimming unit and to which an input voltage from the external power supply is applied, a unidirectional conduction unit electrically connected to the first illumination unit and the second illumination unit, a first current-limiting unit electrically connected to the first illumination unit; and a second current-limiting unit electrically connected to the second illumination unit, wherein the amplitude of the input voltage varies on the basis of a phase-cut angle of the dimming unit, when the amplitude of the input voltage varied on the basis of the phase-cut angle satisfies a first predetermined condition, the unidirectional conduction unit is in a turn-on state, and the illumination device operated in a first operation mode; and when the amplitude of the input voltage varied on the basis of the phase-cut angle satisfies a second predetermined condition, the unidirectional conduction unit is in a turn-off state, and the illumination device operates in a second operation mode. The effect of deepening the dimming depth is achieved.

A power converter can include: a rectifier circuit; a silicon controlled dimmer coupled between an AC input terminal and an input terminal of the rectifier circuit; and a bleeder circuit coupled to an output terminal of the rectifier circuit, and being configured to provide a bleeder current after the silicon controlled dimmer is turned off. A method of controlling a power converter, can include: generating a bleeder current flowing though output terminals of a rectifier circuit of the power converter after a silicon controlled dimmer is turned off; and where the silicon controlled dimmer coupled to the rectifier circuit receives an AC input voltage.

A load control device for controlling power delivered from an AC power source to an electrical load may comprise a thyristor, a gate current path, and a control circuit. The control circuit may be configured to control the gate current path to conduct a pulse of gate current through a gate terminal of the thyristor to render the thyristor conductive at a firing time during a half-cycle of the AC power source. The control circuit may operate in a first gate drive mode in which the control circuit renders the gate current path non-conductive after a pulse time period from the firing time. The control circuit may operate in a second gate drive mode in which the control circuit maintains the gate current path conductive after the pulse time period during the half-cycle.

A load control device for controlling power delivered from an AC power source to an electrical load may comprise a thyristor, a gate current path, and a control circuit. The control circuit may be configured to control the gate current path to conduct a pulse of gate current through a gate terminal of the thyristor to render the thyristor conductive at a firing time during a half-cycle of the AC power source. The control circuit may operate in a first gate drive mode in which the control circuit renders the gate current path non-conductive after a pulse time period from the firing time. The control circuit may operate in a second gate drive mode in which the control circuit maintains the gate current path conductive after the pulse time period during the half-cycle.

An apparatus for an LED driver with a silicon-controlled dimmer, can include: a bleeder circuit coupled to a DC bus of the LED driver; and a controller configured to control the bleeder circuit to draw a bleeder current from the DC bus when a conduction angle of the silicon-controlled dimmer is less than an angle threshold, in order to maintain a conduction state of the silicon-controlled dimmer.

An apparatus for an LED driver with a silicon-controlled dimmer, can include: a bleeder circuit coupled to a DC bus of the LED driver; and a controller configured to control the bleeder circuit to draw a bleeder current from the DC bus when a conduction angle of the silicon-controlled dimmer is less than an angle threshold, in order to maintain a conduction state of the silicon-controlled dimmer.

A self-adjusting luminaire whose primary operation is to provide ambient or focused lighting in a hazardous environment is configured to modify (e.g., continuously) the energization intensity levels of its on-board illumination sources based on magnitudes of difference between an amount of light in the environment of the luminaire (e.g., including both light produced by the luminaire and ambient light) as measured by on-board sensors and a setpoint amount of light corresponding to the luminaire. Further, the self-adjusting luminaire may detect that its on-board sensors are malfunctioning when the illumination sensors fail to sense a change in the amount of light in the environment of the luminaire after the luminaire has modified the energization intensity levels of its illumination sources. Upon detecting a sensor malfunction, the self-adjusting luminaire may generate an alarm, and/or may automatically modify the intensity of its illumination sources to mitigate effects of the detected malfunction.

A mechanical switch dimming and speed regulation control system includes a double-contact mechanical switch including at least one alternating current live wire input end, and at least one group of normally closed contact and normally open contact mutually short-circuited with each other, a dimming and speed regulation controller including a signal collector and a dimming and speed regulation control circuit, and a controlled device, outputs of the normally closed and open contacts loop-connected with the dimming and speed regulation controller, the dimming and speed regulation controller loop-connected with the controlled device, the signal collector electrically connected with an output loop of the double-contact mechanical switch and the dimming and speed regulation control circuit, respectively; the dimming and speed regulation control circuit loop-connected with the controlled device. The present disclosure implements high-power dimming and speed regulation control of a single live wire by using the double-contact mechanical switch, and overcomes problems of power limitation of a conventional dimming and speed regulation switch and difficulty for an intelligent switch to implement dimming and speed regulation of the single live wire.

System and method for controlling one or more light emitting diodes. For example, the system includes: a voltage detector configured to receive a rectified voltage associated with a TRIAC dimmer and generated by a rectifying bridge and generate a first sensing signal representing the rectified voltage; a distortion detector configured to receive the first sensing signal, determine whether the rectified voltage is distorted or not based at least in part on the first sensing signal, and generate a distortion detection signal indicating whether the rectified voltage is distorted or not; and a phase detector configured to receive the first sensing signal and generate a phase detection signal indicating a detected phase range within which the TRIAC dimmer is in a conduction state based at least in part on the first sensing signal.