Signify Holding B.v.

Koninklijke Philips Corporation N.v.

Philips Lighting Holding B.v.

U.S. Philips Corporation

Tijmen Cornelis Van Bodegraven

Harald Josef Günther Radermacher

Haimin Tao

Geert Willem Van Der Veen

Reinhold Elferich

Dmytro Viktorovych Malyna

Patrick Alouisius Martina De Bruycker

Marcus Cornelis Van Meel

Raimundo De Heer Galisteo

Wilhelmus Josephus Cornelissen

Luna X Zhang

Jie Fu

Peter Hubertus Franciscus Deurenberg

Klaas Jacob Lulofs

Zhi Quan Chen

William Peter Mechtildis Marie Jans

Zadok Vitalis Socrates Kroeze

Yuanqiang Liu

Shiguang Sun

Cornelis Johannes Adrianus Schetters

Lino Adriaan Nicolaas Wilhelm De Wit

Yun Fei Duan

Patrick John Zijlstra

Gu Yuan Chen

Yuangiang Liu

Johannus Emmanuel Maria Lammers

Stefan G Mozar

Adam Kurasz

The invention relates to a circuit for providing isolated data transfer. The circuit comprises a sensor adapted to be coupled to a conversion circuit, the conversion circuit, which is adapted to use a signal generated by the sensor and an offset voltage to generate in a time sequential manner, a first voltage level and a second voltage level, wherein the second voltage level is larger than the first voltage level. The circuit comprises a voltage to current transformer circuit adapted to convert the first voltage level into a first current level within a current range and the second voltage level into a second current level within the current range, wherein the first current level and the second current level are time sequentially provided to an optocoupler. The optocoupler is adapted to receive time sequentially the first current level and the second current level and to provide an isolated output voltage having a first voltage when the first current level is provided to the optocoupler and a second voltage when the second current level is provided to the optocoupler, an analog to digital converter adapted to receive the isolated output voltage and adapted to provide a digital output voltage and a controller coupled to the analog to digital converter, wherein the controller is adapted to derive the signal generated by the sensor from the digital output voltage corresponding to the isolated output voltage received in the time sequential manner.

Overvoltage protection integrated in the module temperature protection

A lamp driver has a transformer, a primary side circuit and a secondary side circuit. The primary side circuit comprises a half bridge circuit and a sensor circuit for measuring a conduction time or switching frequency of one of the transistors of the half bridge circuit. An estimate is provided of the output voltage from the measured conduction time.

Lamp driver with voltage sensing

An isolated driver generates a PWM load drive level signal at the primary side and provides this to the secondary side via an optocoupler. Power consumption of the load is also sensed at the primary side. A drive level is sensed at the secondary side and compared at the secondary side with the load drive level to provide an error signal for the primary side controller. A frequency of the PWM load drive level signal is adjusted and the power consumption of the load is monitored in response to the frequency adjustment. The duty cycle of the PWM load drive level signal can then be adapted to compensate for errors introduced by the optocoupler.

Driver circuit and a method of controlling a driver

A lamp driver delivers an output voltage and output current to a lamp load. A current regulating circuit at a secondary side provides a feedback signal for use by the driver when in a current regulation mode. An overvoltage protection circuit detects an overvoltage condition of an output voltage and modulates the feedback signal during detection of the overvoltage condition. The overvoltage condition can then be recognized more easily based on the resulting modulation of the output voltage.

Lamp driver with over voltage protection

A retrofit Light Emitting Diode, LED, lighting device for connection to a ballast, wherein said ballast is arranged to be connected to a mains voltage and arranged to provide for a ballast current, wherein said LED lighting device is arranged to detect a dip in said mains voltage using a zero current detector.

Retrofit light emitting diode, LED, lighting device for connection to a ballast, wherein said LED lighting device is arranged to detect a dip in said mains voltage using a zero current detector

A retrofit lamp is to be used with a ballast. A shunt switch is provided in parallel with an output load and is adapted to shunt input terminals of the lamp using pulse width control so as to tune the current through the lighting element. This current control is used to enable compatibility with different ballasts and to provide dimming control. A detection circuit is used to detect an abnormal drive condition of the retrofit lamp and the pulse width control of the shunt switch can then be overridden by holding the shunt switch at a stable state for a certain duration. This prevents overload conditions and avoids DC signals in the event of component failures.

Retrofit lamp and a lighting system using the same

The invention describes an isolated driver () comprising a converter module () realized to provide voltage and current output to a load (); a feedback arrangement () realized to monitor voltage and/or current during operation of the driver (); and a converter controller () for providing converter control signals (CI, CF, VCON) to the converter module (), and wherein the converter controller () comprises a single optocoupler () connected by input terminals to the feedback arrangement (); and a switching circuit arrangement () connected to output terminals of the optocoupler (), comprising a number of semiconductor switches (Q, Q, Q, . . . , Q) arranged to generate a converter control signal (CI, CF, VCON) for placing the converter module () of the driver () into a low-output mode (M) when a voltage across the optocoupler output terminals indicates a fault condition. The invention further describes an LED lighting arrangement () comprising such an isolated driver () for driving an LED lighting load () from a mains power supply (). The invention also describes a converter controller () for an isolated driver (), and a method of operating an isolated driver ().

Isolated driver

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 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.

A circuit arrangement is disclosed with a regulating circuit which is particularly used for regulating a resonant converter having a plurality of outputs. The arrangement includes a protective circuit that can be constructed with the least possible circuitry and cost. The regulating circuit is used for generating a pulse-width modulated regulation signal (20) in dependence on measuring signals (Va, Vb) present on inputs of the regulating circuit (20). The arrangement further includes a comparator circuit (212) for comparing the duty cycle (&#x3b4;) of the regulation signal (20) with a predefinable maximum duty cycle value (&#x3b4;max) and minimum duty cycle value (&#x3b4;min), in which in case of a duty cycle (&#x3b4;) situated outside the range between the maximum duty cycle value (&#x3b4;max) and the minimum duty cycle value (&#x3b4;min) the circuit arrangement delivers control information that corresponds to this exceeding of the range.

Circuit configuration comprising a control loop

DC/DC conversion circuit ( ), includes a transformer ( ) having a primary winding ( ), a secondary winding ( ), and an auxiliary winding ( ); a switching transistor (T), including a series circuit with the primary winding ( ) between first and second direct current input terminals ( ); a start circuit (R , C ) connected to a control electrode of the switching transistor (T) for switching the switching transistor (T) on by powering the direct current input terminals ( ); a control transistor connected to the control electrode of the switching transistor (T) for switching off the switching transistor (T) in dependence on a current flowing through the series circuit during operation. The auxiliary winding ( ) and the control transistor (Q) connect to a voltage control circuit ( ) for setting an output power provided at the secondary winding ( ) of the transformer ( ) during operation by a controlled switching-on of the switching transistor (T) in dependence on the magnitude of a current flowing in the primary winding ( ). The conversion circuit ( ) is arranged such that during operation via the auxiliary winding ( ) a voltage required at the control electrode of the switching transistor (T) for on thereof is built up in a time period which is inversely proportional to the amount of output power provided at the secondary winding ( ).

DC/DC conversion circuit having a switching frequency proportional to power output

A voltage doubler (2) having a series arrangement of two smoothing capacitors (C1,C2), is able to use less expensive smoothing capacitors (C1,C2) having a far lower rated voltage which is only slightly above the maximum voltage occurring during normal operation. To this end, a first and a second over-voltage prevention circuit (30,31) are coupled across the smoothing capacitors (C1,C2) of the voltage doubler (2) to protect the smoothing capacitors (C1,C2) against over-voltage if one of the smoothing capacitors (C1,C2) is short-circuited. The first and the second over-voltage prevention circuit (30,31 ) may both be an over-voltage detector, or an under-voltage detector each being coupled across one of the smoothing capacitors (C1,C2). It is also possible to combine an over-voltage detector coupled across one of the smoothing capacitors (C1,C2) to an under-voltage detector coupled across the same smoothing capacitor (C1,C2). The over-voltage detector prevents an over-voltage across said one smoothing capacitor (C1,C2) if the other smoothing capacitor (C1,C2) is short-circuited. The under-voltage detector detects a short circuit of the one smoothing capacitor (C1,C2) and thereby prevents an over-voltage across the other.

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Eindhoven, Netherlands

Tijmen Cornelis Van Bodegraven