Abstract: The present invention is aimed at providing a dimmer capable of preventing malfunctions due to noise contamination or waveform distortion of the voltage of an AC power source.

Abstract: A serial-type LED device includes p light source units and a dimming circuit. Each light source unit includes first and second terminals, m light strings and m current balance units. Each light string includes LEDs coupled in series to have a first terminal coupled to the first terminal of a corresponding light source unit and a second terminal coupled to the second terminal of the corresponding light source unit through a corresponding current balance unit. The first terminal of the first light source unit is coupled to a second DC voltage, and the second terminal of the i-th light source unit is coupled to the first terminal of the (i+1)-th light source unit, where m and p are integers greater than or equal to 2, and i is any integer from 1 to (p?1). The dimming circuit coupled to the second terminal of the p-th light source unit controls the second DC voltage according to a current outputted from the p-th light source unit.

Abstract: A lighting ballast and associated methods balance current through resonant inductors that have inductance variation, and are further effective to balance lamp currents in the range from full brightness to full dimming. The ballast includes a lighting power source, a balancing transformer having a plurality of windings, a first resonant tank circuit having one or more transformer windings and a second resonant tank circuit having a like number of transformer windings. Each of the windings for the first resonant tank are reversed in direction in association with a corresponding winding for the second resonant tank, such that the only current passing through the windings is a current difference between the two windings.

Abstract: An inductive LED lamp bulb comprising a male connector, casing, LED, lamp panel and PIR sensor, of which the male connector is set at upper part of the casing, both LED and lamp panel are set at lower part of the casing; moreover, the lamp panel covers said LED, while a controller is embedded into said casing, which is also equipped with a timing switch and a contrast switch; said PIR sensor of a removable structure is mounted at the lower part of the casing, and protruded from said lamp panel; said controller is electrically connected with LED, PIR sensor, timing switch and contrast switch; thus, the utility model can be used as a common LED lamp bulb with more control functions and broader range of applications by disassembling easily the PIR sensor.

Abstract: An LED drive circuit that sufficiently exhibits the performance of an LED element to obtain a favorable luminance at room temperature, includes a constant-current circuit including an LED element, a constant-current output unit, and a temperature sensing element having a negative resistance-temperature coefficient. The LED element is connected to the constant-current output unit in series. The constant-current output unit is connected to the LED element in parallel. Due to changes in the resistance value of the constant-current output unit caused by changes in temperature, the value of a current passing through the LED element is increased at room temperature and the value of a current passing through the temperature sensing element is reduced at high temperature.

Abstract: Methods and apparatus are provided for generating low EMI display driver power supply. The methods and apparatus include switching circuits that utilize two groups of parallel circuit traces, each of which is coupled to one end of a switching device. The two groups of traces are configured to be interleaved with each other such that no two traces from either group are next to any other traces from the same group. When the switching device is activated, current flows through the circuit and charges an energy storage element. When the switching device is deactivated, the energy storage element discharges a portion of its energy to a second energy storage element and to the driver circuits. In another embodiment, an additional circuit trace is provided which is only connected on one end and is free floating on the other end to capture the majority of EMI remaining that was generated by the switching circuit.

Abstract: A driving circuit of a light emitting diode (LED), including a driving unit, a current pre-charging unit and a feedback unit, is provided. The driving unit outputs a driving power to drive the LEDs and outputs at least one first feedback signal according to the current conducted in the LEDs. The current pre-charging unit is coupled to an output of the driving unit to provide a current path to the driving unit and generates a second feedback signal. One of the at least one first feedback signal is selected to adjust the driving power when the enable signal is at a first logic level; the second feedback signal is selected to adjust the driving power when the enable signal is at a second logic level so as to maintain a current to drive the LEDs.

Abstract: A method for setting a color locus of at least one luminous source is provided. The method may include determining a temperature, and setting the color locus of the at least one luminous source depending on the temperature determined.

Abstract: A method for setting a color location is provided. The method may include providing n luminous sources of which n-3 luminous sources have been, or are preset; determining a color location difference of the n luminous sources from a desired color location; and setting the 3 luminous sources not preset are set such that the desired color location is achieved.

Abstract: Embodiments of the invention provide a DC/DC converter. The DC/DC converter includes a transformer, a switch controller and a driver controller. The transformer has a primary winding coupled to a power source, a first secondary winding provides a first output voltage to a first load, and a second secondary winding provides a second output voltage to a second load. The switch controller is coupled to the primary winding and controls a first switch coupled to the primary winding to control input power to the primary winding and to regulate the first output voltage based on a power requirement of the first load. The driver controller is coupled to the second secondary winding and generates a pulse modulation signal to alternately turn on and turn off a second switch coupled to the second secondary winding to regulate the second output voltage based on a power requirement of the second load.

Abstract: A light emitting diode (LED) lighting system includes a PFC and output voltage controller and a LED lighting power system. The controller advantageously operates from an auxiliary voltage less than a link voltage generated by the LED lighting power system. The common reference voltage allows all the components of lighting system to work together. A power factor correction switch and an LED drive current switch are coupled to the common reference node and have control node-to-common node, absolute voltage that allows the controller to control the conductivity of the switches. The LED lighting system can utilize feed forward control to concurrently modify power demand by the LED lighting power system and power demand of one or more LEDs. The LED lighting system can utilize a common current sense device to provide a common feedback signal to the controller representing current in at least two of the LEDs.

Abstract: Provided is an LED driving apparatus capable of improving a power factor through a non-insulation type simplified circuit structure, including: a light emitting unit having at least one LED; a rectifier rectifying an alternate current (AC) voltage applied from external power; a power supply unit supplying driving power to the light emitting unit, and having an inductor connected to an output terminal of the light emitting unit; and a switch controller.

Abstract: A DMX based wireless, light emitting device and system including wireless modules that are battery powered and wirelessly receive and transmit DMX to other modules or a controller device. The modules can optionally be hard wired to both a DMX signal and external power supply. An integrated processor can independently control a pre-selected lighting effects, channels, addresses, programs and other light effect features.

Abstract: A driving circuit system for a gas discharge lamp includes a power circuit having a switch for converting an input voltage into a lamp voltage for driving the gas discharge lamp, a lamp current detecting circuit connected to the power circuit or the gas discharge lamp for detecting a lamp current, a feedback circuit connected to the lamp current detecting circuit for generating a lamp current feedback signal, a constant power control circuit for generating a corrected current reference signal, and a power control circuit connected to the feedback circuit, the constant power control circuit, and the switch of the power circuit for generating a first modulating signal in accordance with the lamp current feedback signal and the corrected current reference signal for driving the switch to turn on or off, thereby substantially maintaining a lamp power of the gas discharge lamp at a constant value.

Abstract: A circuit capable of receiving, in series with at least one light-emitting diode, a rectified A.C. voltage, comprising: a first gate turn-off thyristor connected to first and second terminals of the circuit; and a control circuit for turning off the first thyristor when the voltage between the first and second terminals exceeds a threshold.

Abstract: A light source apparatus includes a light source disposed adjacent to a side portion of a light guide plate and a light source driver driving the light source. The light source driver includes a booster and a protecting circuit. The booster boosts an input voltage to a driving voltage for driving the light source. The protecting circuit selectively cuts off the input voltage applied to the booster according to an output current of the booster, reducing the risk of damage to the driver due to shorts, overcurrents, or the like.

Abstract: To prevent biased consumption of electrodes in a discharge lamp and to prevent biased precipitation of the electrode material, a light source is provided. The light source device has a discharge lamp that emits light by discharge between a first electrode and a second electrode; and a driver that supplies alternating current to the first and the second electrodes so as to maintain the discharge, and changes duty ratio of the alternating current in accordance with predetermined pattern. The predetermined pattern includes a plurality of section periods for which the duty ratio maintains mutually different values for a predetermined period.

Abstract: An EL display device capable of performing clear multi-gradation color display and electronic equipment provided with the EL display device are provided, wherein gradation display is performed according to a time-division driving method in which the luminescence and non-luminescence of an EL element (109) disposed in a pixel (104) are controlled by time, and the influence by the characteristic variability of a current controlling TFT (108) is prevented. When this method is used, a data signal side driving circuit (102) and a gate signal side driving circuit (103) are formed with TFTs that use a silicon film having a peculiar crystal structure and exhibit an extremely high operation speed.

Abstract: A lighting system includes a transformer having a primary winding on a receiving path and a secondary winding on a delivering path. The receiving path receives electric energy regulated based on a dimming angle. The delivering path delivers the received electric energy. The lighting system includes a secondary switch, and a dimming controller. The secondary switch is switched on to couple a light source, such as an LED array, and the like, with the delivering path to emit light in response to the delivered electric energy and is switched off to decouple the light source from the delivering path. The dimming controller is configured to detect the dimming angle based on an electrical property of the delivering path. Then, the dimming controller switches on and switches off the secondary switch based on the dimming angle.

Abstract: The invention provides a lamp circuit of a light emitting device, which comprises a capacitor, a rectification unit, a current limiting unit, and a light emitting device. The capacitor is connected to the two lamp contacts of the lamp holder of the electrical ballast to change the resonant frequency of the resonant circuit of the electrical ballast. The rectification unit is connected to the capacitor, and utilized to rectify a sine-wave voltage to a direct current voltage. The current limiting unit is connected to the rectification unit, outputting a direct current corresponding to the direct current voltage. The light emitting device is connected to the current limiting unit and the rectification unit to generate a light source. With the invention, the light emitting device can be installed directly in a lamp holder of a conventional fluorescent lamp.