Philips Lighting Holding B.v.

Koninklijke Philips Corporation N.v.

Signify Holding B.v.

Wilhelmus Josephus Cornelissen

Geert Willem Van Der Veen

Patrick Alouisius Martina De Bruycker

Tijmen Cornelis Van Bodegraven

Harald Josef Günther Radermacher

Peter Hubertus Franciscus Deurenberg

Klaas Jacob Lulofs

Yuhong Fang

Lino Adriaan Nicolaas Wilhelm De Wit

Fokko Jan Willem Hulshof

Sreeraman Venkitasubrahmanian

A light emitting diode (LED) apparatus is provided for driving a plurality of LED lamps (in parallel. The light emitting diode apparatus includes at least one LED driver circuit to provide a LED driving current for the plurality of LED lamps. The LED driver circuit includes a current setting resistance circuit for setting a maximum value of the LED driving current and a detection circuit to detect presence or absence of each of the plurality of LED lamps by detection of the current flowing through each of the LED lamps. The detection circuit adjusts the current setting resistance circuit based on the detection of presence or absence and the current setting resistance circuit includes a plurality of setting resistors and a plurality of transistors.

LED lamp(s) with single channel driver

The invention relates to a LED light source comprising:

LED light source with improved glow reduction

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

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.

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Eindhoven, Netherlands

Wilhelmus Josephus Cornelissen