Abstract: A light-emitting device includes a substrate including electrodes, a first group including a plurality of blue light-emitting diode elements that are disposed on the substrate and electrically connected to the electrodes, a second group including a plurality of blue light-emitting diode elements that are disposed on the substrate and electrically connected to the electrodes, a fluorescent layer disposed to receive light from the first group of blue light-emitting diode elements, and a phosphorescent layer disposed to receive light from the second group of blue light-emitting diode elements.

Abstract: The invention provides a light emitting diode (LED) centralized DC (direct-current) power supply system and operating methods thereof. The proposed DC power supply system comprises a three-phase AC (alternating-current) input interface, a DC power supply output interface, N+1 three-phase PWM (pulse width modulation) rectifier modules, LED cluster loads and a power supply management module. The proposed operating methods are described as following: the power supply management module adjusts the duty ratio of the three-phase PWM rectifier modules, based on the control signals formed by synthesizing the information about voltage and current of the positive and negative output buses, the three-phase AC input ends, control signals and output of the three-phase PWM rectifier modules, hence AC voltage of power grid can be directly converted into adjustable DC voltage by the PWM rectifier.

Abstract: A system for capacitively transferring power to LEDs using intrinsic circuit board capacitance is disclosed. The plates of the capacitor are foil on either side of an insulating substrate. An AC source may deliver energy to a circuit, featuring an intrinsic circuit board capacitor in series with an LED.

Abstract: The invention describes an AC-LED lighting circuit (1) comprising an AC-LED arrangement (10) with at least a first set (11) of LEDs connected according to a first polarity and a second set (12) of LEDs connected according to the opposite polarity, which AC-LED lighting circuit (1) is characterized by (i) a source (61) of a polarity-selectable DC input signal (51) to be applied to the AC-LED arrangement (10), or a connecting means (40) for connecting the AC-LED lighting circuit (1) to a fixed-polarity DC input signal (50) and a conversion means (T1, T2, T3, T4) for converting the fixed-polarity DC input signal (50) to a polarity-selectable DC signal (50?) to be applied to the AC-LED arrangement (10); and (ii) a polarity controller (70, 71) realized to control the polarity of the polarity-selectable DC signal (50?, 51) applied to the AC-LED arrangement (10) such that the first set (11) of LEDs of the AC-LED arrangement (10) is driven when the polarity-selectable DC signal (50?, 51) has the first polarity, and t

Abstract: An illumination device (1) comprises: mains input terminals (2, 3); a power source (30), having input terminals (31, 32) coupled to the mains input terminals and having three output terminals (33, 35, 34), one of said output terminals being a common output terminal (35). A first output (36) is defined by a first output terminal and said common output terminal; a second output (37) is defined by a second output terminal and said common output terminal. A first LED string (110) is connected to the first power source output in series with a first resistor (120). A second LED string (210) is connected to the second power source output in series with a second resistor (220). The power source is controllable to vary the voltage at the common output terminal within the range from the voltage at the first output terminal to the voltage at the second output terminal.

Abstract: A three phase rectifier rectifies received three phase a.c. power to generate a ripple d.e. voltage. A power distribution bus conveys distribution power comprising the ripple d.c. voltage or an a.c. voltage derived therefrom to a location of an LED based lamp that is distal from the three phase rectifier. Additional circuitry disposed with the LED based lamp drives the LED based lamp using the distribution power.

Abstract: The present invention relates to a backlight unit that includes at least one first light emitting diode (LED) package and at least one second LED package, wherein the first LED package includes a blue LED chip, a green LED chip, and a first phosphor, the first phosphor being excited by blue light and to emit light to be mixed with blue light and green light respectively emitted from the blue LED chip and the green LED chip, the first LED package to thereby emit white light. The second LED package includes a blue LED chip, a red LED chip, and a second phosphor, the second phosphor being excited by blue light and to emit light to be mixed with blue light and red light respectively emitted from the blue LED chip and the red LED chip, the second LED package to thereby emit white light.

Abstract: A circuit arrangement (1) for a light emitting device, comprising a first circuit branch (2) for receiving an AC voltage and comprising a first light emitting diode (LED) circuit (3) serially connected with a first phase-shifting element (4), a second circuit branch (12) connected in parallel with the first circuit branch, the second circuit branch comprising a second LED circuit (13) serially connected to a second phase-shifting element (14), in reverse order compared with the LED circuit and phase-shifting element in the first circuit branch, and a third circuit branch (22) comprising a third LED circuit (23) connected between the first and second branches. With such a circuit design, the current through the first and second LED can be phase shifted compared with the current though the third LED circuit, so that the first and second light emitting diode circuits emit light during one time period, while the third light emitting diode circuit emits light during a second period.

Abstract: An AC light emitting device is disclosed. The AC light emitting device includes at least four substrates. Serial arrays each of which has a plurality of light emitting cells connected in series are positioned on the substrates, respectively. Meanwhile, first connector means electrically connect the serial arrays formed on respective different substrates. At least two array groups each of which has at least two of the serial arrays connected in series by the first connector means are formed. The at least two array groups are connected in reverse parallel to operate. Accordingly, there is provided an AC light emitting device capable of being driven under an AC power source.

Abstract: An LED lighting system has a constant AC current source, a circuit loop and a plurality of light emitting diodes in the circuit loop. The constant AC current source eliminates the need for integrated circuits and other circuit components that can fail or be damaged in a light fixture, particularly an outdoor, landscape lighting fixture. The LED lighting system preferably contains a current transformer and/or a full wave bridge rectifier to maximize the number of LEDs in a lighting system—and/or a voltage clamping circuit to minimize the chance of run-away voltage.

Abstract: The present invention relates to a backlight unit that includes at least one first light emitting diode (LED) package and at least one second LED package, wherein the first LED package includes a blue LED chip, a green LED chip, and a first phosphor, the first phosphor being excited by blue light and to emit light to be mixed with blue light and green light respectively emitted from the blue LED chip and the green LED chip, the first LED package to thereby emit white light; the second LED package includes a blue LED chip, a red LED chip, and a second phosphor, the second phosphor being excited by blue light and to emit light to be mixed with blue light and red light respectively emitted from the blue LED chip and the red LED chip, the second LED package to thereby emit white light; and the first LED package and the second LED package are alternately arranged.

Abstract: An AC light emitting device is disclosed. The AC light emitting device includes at least four substrates. Serial arrays each of which has a plurality of light emitting cells connected in series are positioned on the substrates, respectively. Meanwhile, first connector means electrically connect the serial arrays formed on respective different substrates. At least two array groups each of which has at least two of the serial arrays connected in series by the first connector means are formed. The at least two array groups are connected in reverse parallel to operate. Accordingly, there is provided an AC light emitting device capable of being driven under an AC power source.

Abstract: A circuit arrangement (1) for a light emitting device, comprising a first circuit branch (2) for receiving an AC voltage and comprising a first light emitting diode (LED) circuit (3) serially connected with a first phase-shifting element (4), a second circuit branch (12) connected in parallel with the first circuit branch, the second circuit branch comprising a second LED circuit (13) serially connected to a second phase-shifting element (14), in reverse order compared with the LED circuit and phase-shifting element in the first circuit branch, and a third circuit branch (22) comprising a third LED circuit (23) connected between the first and second branches. With such a circuit design, the current through the first and second LED can be phase shifted compared with the current though the third LED circuit, so that the first and second light emitting diode circuits emit light during one time period, while the third light emitting diode circuit emits light during a second period.

Abstract: The present invention relates to a backlight unit that includes at least one first light emitting diode (LED) package and at least one second LED package, wherein the first LED package includes a blue LED chip, a green LED chip, and a first phosphor, the first phosphor being excited by blue light and to emit light to be mixed with blue light and green light respectively emitted from the blue LED chip and the green LED chip, the first LED package to thereby emit white light; the second LED package includes a blue LED chip, a red LED chip, and a second phosphor, the second phosphor being excited by blue light and to emit light to be mixed with blue light and red light respectively emitted from the blue LED chip and the red LED chip, the second LED package to thereby emit white light; and the first LED package and the second LED package are alternately arranged.

Abstract: A ballast (20) for powering at least one gas discharge lamp (52) from a three-phase AC voltage source (30) comprises a three-phase rectifier circuit (200), a high frequency filter capacitor (300), a high frequency inverter (400), and a three-phase EMI filter (500). Three-phase EMI filter (500) comprises a common-mode EMI inductor (510), a Y-capacitor (540), and a plurality of X-capacitors (550,560,570). Common-mode EMI inductor (510) comprises three magnetically coupled windings (512,514; 522,524; 532,534) each of which is, preferably, split into two equal winding sections. Ballast (20) and three-phase EMI filter (500) provide substantial cost and performance benefits in comparison with existing approaches.

Abstract: A ballast (10) for powering at least one gas discharge lamp (52) from a three-phase AC voltage source (30) comprises a three-phase rectifier circuit (200), a high frequency filter capacitor (300), and a high frequency inverter (400). Preferably, three-phase rectifier circuit (200) is implemented by a six-diode bridge, and high frequency filter capacitor (300) can be realized by a film capacitor or a ceramic capacitor. Ballast (10) provides a high power factor and low total harmonic distortion without requiring a dedicated power factor correction circuit. Other benefits of ballast (10) include enhanced efficiency, longer life, and lower inrush current.

Abstract: A kinetically multicolored light source is described, comprising: a light source capable of producing a plurality of primary colors; oscillatory means for driving said light source; and means for moving said light source. The oscillatory driving means may drive the light source so that one or more of the primary colors is alternately turned on and off at a frequency above the critical fusion frequency of an observer, whereby each of the colors appears to emanate simultaneously and continuously thereby appearing to the observer as a single secondary color when the light source moves slowly with respect to the observer.The light source may move relative to the observer sufficiently rapidly that each of the oscillating primary colors if viewed alone would appear to the observer to emanate from bright segments of a curvilinear path with intervening dark segments.

Abstract: A ballast for a gas discharge lamp circuit has a d-c output which contains three series-connected diodes connected across the output terminals, a pair of capacitors connected from different respective nodes of the diodes to respective ones of the output terminals, and a resistor connected between two of the diodes. The resistor increases the circuit power factor to greater than 0.95.

Abstract: An electronic ballast circuit for two fluorescent lamps connected in parallel. A single switching inverter connected through a common coupling circuit provides high frequency alternating current for operation of both lamps independently of each other insuring operation of one lamp should the other cease operation. A dual toroidal transformer in the inverter insures both lamps receive current of the same frequency.

Abstract: A circuit for producing four indications on a bicolor light emitting diode (LED) includes a ring oscillator, with two inputs controlling inverters of opposite phase. By enabling or disabling these inverters, either, both, or neither dies of the LED are energized, causing it to emit light of either of its two primary colors, a secondary color formed by the combination of its two primaries, or no light, respectively. Nonlinear resistances are used to equalize the brightness of the two primaries and set the hue of the secondary.

Abstract: A system for lighting fluorescent lamps, includes a plurality of fluorescent lamps, a transformer for generating filament voltage and a starting voltage for the fluorescent lamps, a switching circuit for sequentially and periodically opening and closing a plurality of its contacts and a driving circuit for electrically biasing the transformer and the switching circuit. A starting voltage is sequentially applied to the fluorescent lamps which are each independently connected to one of the contacts so that the fluorescent lamps may be sequentially turned on.