Koninklijke Philips Corporation N.v.

Philips Lighting Holding B.v.

Signify Holding B.v.

Koninklijke Philips Electronics N.v.

Geert Willem Van Der Veen

Tijmen Cornelis Van Bodegraven

Everaard Marie Jozef Aendekerk

Wilhelmus Josephus Cornelissen

Peter Deixler

Arnold Willem Buij

Patrick Alouisius Martina De Bruycker

Paul Stravers

Jeroen Snelten

Cornelis Jojakim Jalink

Harald Josef Günther Radermacher

Wilhelmus Hinderikus Maria Langeslag

Peter Hubertus Franciscus Deurenberg

Klaas Jacob Lulofs

Roger Peter Anna Delnoij

Johannes Hendrik Wessels

Wijnand Johannes Rietman

Dennis Johannes Antonius Claessens

Markus Cornelius Vermeulen

Johan Wilhelmus Hermanus Kuppen

Antonius Henricus Peterus Johannes Habraken

Lino Adriaan Nicolaas Wilhelm De Wit

Johannes Antonius Kwakman

Marco Foggi

Arnold Willem Buji

Everaard Marie Jozef Aenderkerk

Roger P A Delnoij

Johannes T C Van Kemenade

Eugen De Mol

Arnold W Buij

Bram J W A Bruekers

Bartholomeus J A Corstiaans

Marcus J G M Hendriks

Johan W H Kuppen

Bertrand Johan Edward HontelÉ

Peter H F Deurenberg

The invention relates to a LED light source comprising: input terminals (K, K) for connection to a mains voltage supply source, a rectifier (RB) coupled to the input terminals for rectifying the mains supply voltage supplied by the mains supply voltage source and comprising rectifier output terminals, a DC-DC converter (CONV) for generating a DC current out of the rectified mains supply voltage, comprising converter input terminals connected to the rectifier output terminals and comprising a first converter output terminal (A) and a second converter output terminal (B), &#x2014;a LED load (LL) with an anode coupled to the first converter output terminal via a current control element (D) for blocking a current flowing from the anode of the LED load to the first converter output terminal, and with a cathode coupled to the second converter output terminal via a first controllable switch (M) having a control electrode coupled to first control circuitry for rendering the controllable switch non-conductive in case the LED light source is in standby mode.

LED light source

The invention relates to LED lighting system comprising a power supply circuit and one or more LED modules. The power supply circuit is equipped with input terminals (K, K) for connection to a supply voltage source and first and second output terminals (K, K), and a driver circuit (I, II) coupled between the input terminals and the first and second output terminals for generating a LED current. The driver circuit (I, II) comprises a driver control circuit (II) equipped with an input terminal (K) for increasing or decreasing the LED current in dependency of a signal present at the input terminal of the driver control circuit. The one or more LED modules comprise first and second input terminals (K, K) for connection to respectively the first and second output terminals of the power supply circuit, a series arrangement of a LED load (LS) and a current sensor (R) coupled between the input terminals, a module control circuit for generating a current control signal at an output terminal of the module control circuit and coupled to the current sensor and to a reference signal generator (R, R, R, Z) for generating a reference signal representing a desired magnitude of the LED current, wherein the current control signal has a first value in case the desired value of the LED current is lower than the measured value of the LED current and a second value in case the desired value of the LED current is higher than the measured value of the LED current, and coupling circuitry (D; Sg, DC, C, C) coupled during operation between the output terminal of the module control circuit and the input terminal of the driver control circuit, for communicating the first value of the current control signal to the input terminal of the driver control circuit and for blocking the second value, and wherein the signal at the input terminal of the driver control circuit has a default value when all the current control signals have their second value.

LED lighting system

A lighting unit () includes light emitting diode (LED) modules () and a lighting driver () connected to the LED modules. Each LED module includes LEDs () and an identification current source () supplying an identification current to an identification current output node (). All of the identification current output nodes are connected together to supply a total identification current having a magnitude which changes in response to the number of LED modules that are connected to the lighting driver. The lighting driver includes: a controllable current source (&) to supply an LED driving current to the LEDs of the LED modules, and a controller () that responds to the total identification current to control the controllable current source to supply the LED driving current at a magnitude which changes in response to the number of LED modules that are connected to the lighting driver.

Self-adjusting lighting driver for driving lighting sources and lighting unit including self-adjusting lighting driver

The invention relates to a LED lighting system comprising a power supply circuit for supplying a LED current, equipped with input terminals (K, K) for connection to a supply voltage source and output terminals (K, K), modulation circuitry (MS, DC), coupled between the output terminals, for alternately maintaining the voltage between the output terminals at a high level during a first time interval and a low level during a second time interval, a current sensor (R, R, S) for sensing the current through the output terminals during the second time interval, and a driver circuit (DC, DC), coupled between the input terminals and the output terminals and coupled to the current sensor, for generating the LED current, out of a supply voltage supplied by the supply voltage source, wherein the LED current equals the current sensed by the current sensor multiplied by a predetermined constant multiplication factor and for supplying the LED current to the output terminals during each first time interval. The LED lighting system further comprises a LED module comprising LED module input terminals (K, K) for connection to the output terminals of the power supply circuit, a LED load (LS) coupled between the LED module input terminals with a forward voltage that is higher than the voltage that is present between the output terminals of the power supply circuit during each second time interval, and a current source (CS) coupled between the input terminals for, in case the LED module input terminals are connected to the output terminals of a power supply source, during each second time interval generating a sensor current through the current sensor that is equal to a desired LED current divided by the predetermined constant multiplication factor.

Disclosed is a light source having a plurality of light elements and a control system for controlling the light elements. The control system includes a plurality of light element controllers, each connected to a respective light element, and arranged to obtain light element data; and a bus interface, which is connected to the light element controllers via a light source bus. The bus interface provides the light element controllers with a general command, and the light element controllers generate light element drive signals on basis of the general command and the light element data.

Light source luminaire system light element control

A dimmable LED driver circuit comprises a resonant DC-DC converter coupled to an output circuit. The converter comprises a half bridge or full bridge switching circuit coupled to a resonant circuit. An output of the resonant circuit is rectified and fed to the output circuit. The output circuit may comprise at least one LED series or shunt switch for switching an LED unit on and off. A control circuit controls the switches of the switching circuit at a variable switching frequency. The control circuit is also configured for controlling the switching circuit for amplitude modulating the converter and for pulse-width modulating the converter at a first pulse-width modulation frequency lower than the switching frequency. The control circuit is may further be configured for controlling the switching of the LED switch at a second pulse-width modulation frequency lower than the switching frequency.

Dimming of LED driver

A power supply circuit has an LLC converter stage for converting a DC voltage input into a DC voltage output, and at least one hysteretic converter stage. Each hysteretic converter stage has a DC voltage input coupled to the DC voltage output of the LLC converter stage, and a DC current output. The LLC converter stage lacks a feedback control, and is operated at its load independent point. A ripple on the DC voltage output of the LLC converter does not affect the output current of the hysteretic converter stage. The stable DC current output of the hysteretic converter stage is coupled to a load having one or more LED strings.

Low cost power supply circuit and method

Light source having a plurality of light elements () and a control system for controlling the light elements. The control system comprises a plurality of light element controllers (), each connected to a respective light element (), and arranged to obtain light element data; and a bus interface (), which is connected to the light element controllers () via a light source bus (). The bus interface () provides the light element controllers () with a general command, and the light element controllers generate light element drive signals on basis of the general command and the light element data.

Light source luminaire system light element control by symbol tag interpreter

A lighting device () comprises a plurality of LEDs (-) producing light (-) of mutually different colors. The LEDs are driven in switching cycles () with a duty cycle controlled supply current of constant magnitude. In each switching cycle, each LED is first switched ON () and then switched OFF (). In a measuring mode, during one switching cycle (B), all ON phases of all LEDs are briefly interrupted, except for one LED (), so that a light sensor () measures the light from this one LED. This measurement can be used to adapt the duty cycle of this one LED. In the next switching cycle (C), the interruption of the ON phases is compensated by extending the ON phases of all LEDs except said one LED, the extension having a duration equal to the duration (&#x3c4;) of the interruption.

Method and device for driving a multicolor light source

A lighting device () comprises a LED (), a driver (), and a controller () which regularly switches from a drive state to a measuring state and back. In the measuring state, the controller controls the driver such that the driver does not generate any LED current. The LED produces a measuring signal (Sm) indicating a measured light level. The controller processes the measuring signal received from the LED, and makes a decision on the desired light output of the LED. In the drive state, the controller controls the driver such that the average light output produced by the LED corresponds to the desired light output as determined in the measuring state. In a possible embodiment, the driver generates a nominal LED current I, and sets the duration (&#x3c4;) of the drive state on the basis of the desired light output of the LED as determined in the measuring state.

Lighting device with a LED used for sensing

A method for dimming an illumination system () capable of emitting light (L) with a variable color is described. The illumination system () comprises three dimmable light sources () generating respective lights (L, L, L) having respective, mutually different colors (C, C, C). The method comprises the step of reducing the light intensities (I, I, I) of the three dimmable light sources () while maintaining the color point until one of said light sources () reaches a lower dim limit (I)&#x2014;The method further comprises the step of maintaining the light intensity (I) of said one light source () at its lower dim limit (I) and reducing the light intensities (I, I) of the two other dimmable light sources () in such a manner that the hue is maintained.

Method for dimming a light generatng system for generating light with a variable color

A lamp driver circuit () comprises a feedback circuit for controlling stable operation of a discharge lamp (La), e.g. an inductively coupled discharge lamp such as a molecular radiation lamp, and for controlling a light output level of the discharge lamp (La). In particular, if the discharge lamp (La) is operated at a dimmed light output level, the light output is sensitive to changes in the lamp voltage (V), possibly resulting in flickering. In order to control stable lamp operation and prevent flickering, a high-sp feedback circuit is provided for controlling an operating frequency. In order to provide a relatively large dimming range for controlling the light output level, a low-speed feedback circuit is provided for controlling a DC supply voltage level (V).

Lamp driver circuit and method for driving a discharge lamp

A drive circuit for driving a fluorescent tube lamp comprises a variable frequency oscillator generating a lamp drive frequency, a resonant drive circuit driving the lamp with the lamp drive frequency, and a control unit for driving the variable frequency of the latter under control of a synchronization signal. When a pre-heating frequency is generated by the variable frequency oscillator, the lamp is pre-heated while when an illumination drive frequency is generated, the lamp ignites and operates in its illuminated state. The control unit comprises a transition controller for at an ignition of the lamp limiting the drive frequency to an ultimate ignition frequency, and only enabling transition from the ultimate ignition frequency to the illumination drive frequency after an ignition delay time.

Fluorescent tube lamp drive circuit

A fluorescent lamp (), in particular a backlight lamp of a display device, is supplied with an alternating voltage, a frequency and an amplitude of which being greater during ignition than during normal operation of the lamp. The voltage (V) across the lamp and the current (I) through the lamp are measured to provide a measured voltage value and a measured real lamp current value. From the alternating voltage there is derived a voltage (V). The measured voltage value is multiplied by the sum of the measured real lamp current value and the derived voltage. The multiplication result (P=V*(I+V)) is compared with a reference value (Ref), which results in a difference or error value. The error value is used to control the frequency and the amplitude of the alternating voltage (V), such that the error value is minimized.

Power control of a fluorescent lamp

A ballast circuit for operating a discharge lamp equipped with a control loop for controlling the power consumed by the lamp. A first circuit part is coupled to the discharge lamp and to input terminals for connection to a source of supply voltage for the ballast circuit. The first circuit part is coupled to the input terminals to supply lamp current from the supply voltage. The control loop includes a second circuit part coupled to the first circuit to generate a first signal that represents a desired value of lamp power. A third circuit part is coupled to the input terminals for generating a second signal that depends on the amplitude of the supply voltage. A fourth circuit part has an input coupled to the third circuit part and an output coupled to an input of the second circuit part for adjusting the value of the first signal dependent upon the second signal. The power consumed by the lamp is decreased when the amplitude of the supply voltage decreases. Too high currents in the ballast circuit are thereby prevented.

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Eindhoven, Netherlands

Geert Willem Van Der Veen