Philips Lighting Holding B.v.

Signify Holding B.v.

Philips Lumileds Lighting Company LLC

Dennis Claessens

Kumar Arulandu

Patrick Alouisius Martina De Bruycker

Philip Louis Zulma Vael

Yi Wang

Paul R Veldman

Georg Sauerländer

Robertus Leonardus Tousain

Ronald Hans Van Der Voort

Dalibor Cvoric

Emanuel Stassar

Sait Izmit

Robert F M Hendriks

Yufei Zhou

Pieter Grootes

Noboru Kaito

Charles A Schrama

Sait I Zmit

Henglian Luo

Georg SAUERLÄNDER

A dual-switch flyback converter in which the output current, in operating regions where a constant output current is required, can be regulated from the primary side. The output current is regulated constantly regardless of the input and output voltages by compensating the peak current in the primary winding with the average current in the clamping diode, or the conduction duration of the clamping diode.

Flyback converter and LED driver using the flyback converter

A lighting device is configured to receive a first voltage signal, and includes: a first circuit coupled to input terminals for receiving the first voltage signal, the first circuit including: rectifying diodes for rectifying the first voltage signal and supplying a second voltage signal, a first capacitor for buffering the second voltage signal, and a second capacitor coupled in parallel to one of the rectifying diodes of the first circuit; a second circuit receiving an input voltage signal, corresponding to the second voltage signal, and converting the input voltage into an output signal; and a light circuit receiving the output signal of the second circuit and including at least one light emitting diode, wherein the first circuit includes a fourth circuit in parallel to the second capacitor, the fourth circuit including at least two fourth circuit diodes and being connected by a fourth capacitor to one of the input terminals.

Lighting device suitable for multiple voltage sources

Control circuits () bring power converters () in different modes in response to detection results. The power converters () exchange possibly rectified first voltage/current signals with electronic halogen transformers () and supply second voltage/current signals to light emitting diode circuits (). The first current signals have, in different modes, different amplitudes. The different amplitudes have different constant values and/or different derivative values. As a result, the first current signal has become a relatively varying first current signal. Then, the halogen transformers () no longer experience problems that occur when smaller amounts of power need to be provided than designed to. The detections may comprise polarity detections of and/or zero-crossing detections in the first voltage signals. The halogen transformers () comprise self-oscillating switched mode power supplies designed to provide first amounts of power at their outputs. The light emitting diode circuits) are designed to consume second amounts of power smaller than the first amounts.

Power converter between halogen transformer and LED

An LED backlight structure for setting voltages and currents for LEDs. Red LEDs are connected in series between a first voltage regulator and a first controllable current source, green LEDs are connected in series between a second voltage regulator and a second controllable current source, blue LEDs are connected in series between a third voltage regulator and a third controllable current source. The current sources may be linear current regulators controlled to balance the three colors to achieve a target light output of the board using a light detection chamber. PWM controllers control transistor switches connected in parallel across groups of LEDs, where the duty cycles set the average current through each group of LEDs. The control values used to achieve target light characteristics are stored in memory. The PWM controller may control brightness levels of the LEDs. The backlight may be for an LCD television.

LED light source for backlighting with integrated electronics

Growing community of inventors

Eindhoven, Netherlands

Dennis Claessens