Philips Lighting Holding B.v.

Koninklijke Philips Corporation N.V.

Signify Holding B.v.

Koninklijke Philips Electronics N.v.

Sait Izmit

Philip Louis Zulma Vael

Yi Wang

Patrick Alouisius Martina De Bruycker

Dennis Johannes Antonius Claessens

Georg Sauerländer

Kumar Arulandu

Robertus Leonardus Tousain

Ronald Hans Van Der Voort

Dalibor Cvoric

Aldegonda Lucia Weijers

Theodoor Cornelis Treurniet

Antonius Maria Rijken

Michel Gerardus Pardoel

Ravindra Bhat

Aldo Tralli

Lihua Lin

Dennis Claessens

Dennis Erwin Bos

Martijn Evert Paul Jansen

Jascha Van Pommeren

Jan Wojciech Obrebski

Paul Robert Veldman

Georg SAUERLÄNDER

A circuit arrangement for controlling the brightness of at least one LED unit is described by the disclosure. The circuit arrangement, in one example, includes an input for receiving a phase-cut operating voltage from a power supply, a signal processor, connected with the input and adapted to provide a dimming signal for the at least one LED unit from the operating voltage. To allow an efficient reduction of noise in the dimming signal but simultaneously to allow an improved dimming of the LED unit, the signal processor are configured to operate at least in a noise suppression mode and a dimming mode. A control device is provided, connected with the signal processor and configured to set the mode of the signal processor in dependence of the variation in the operating voltage.

Circuit arrangement for controlling a LED unit and method of operating the same

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

A lamp comprising a driver assembly, the driver assembly including a driver board with driver electronics, at least one point light source and a heat sink, the heat sink including a top side and a bottom side, a central space extending from the bottom side to the top side and adapted for receiving the driver board of the driver assembly, a zone provided at the top side and adapted for receiving the at least one point light source, wherein a plurality of fins adapted for dissipating heat are extending on opposite sides of the central space, and an extension of the central space in at least one radial direction of the heat sink is larger than an extension of the zone in the radial direction of the heat sink such that the central space is provided with at least one section arranged offset from and radially adjacent to the zone.

Lamp with a heat sink

Circuits () for receiving output signals from transformers () comprise filters () and switches (). In the case of magnetic/electronic transformers, the filters () are activated/deactivated, for example for filtering/not filtering unwanted signals coming from converters (). The filters () may comprise capacitors. The switches () may comprise fuses. Output signals of magnetic/electronic transformers comprise relatively low/high frequency signals that result in relatively small/large currents flowing through the capacitors, which currents will not blow/blow the fuses. The capacitors, when activated, form, together with leakage inductances of the magnetic transformers, electromagnetic interference filters. Alternatively, the circuits () may further comprise detectors () for detecting transformer types and for controlling the switches () in response to detection results. Then, possibly, the detectors () are arranged to detect frequency signals in the output signals and comprise comparators () for comparing detection results () with threshold values.

Output circuit for magnetic / electronic transformer

A steering system () comprises two radially oppositely arranged drive wheels () for steering a tubular object () positioned between the drive wheels (). The drive wheels () each have a wheel rotation axis () and each include a plurality of rollers () distributed around the wheel rotation axis (). The rollers () are rotatably arranged, each roller having a roller rotation axis () and an outer drive face () concavely vaulted in a direction corresponding to its roller rotation axis (). The roller rotation axis () is obliquely oriented in relation to the wheel rotation axis () and the rollers () of each drive wheel () form together a steering periphery for the tubular object (). The steering system enables continues rotation of a tubular object without danger that the object will lose the contact with the rollers. The steering system () may be incorporated in a catheter system which comprises a catheter ().

Steering system and a catcher system

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Utrecht, Netherlands

Sait Izmit