Signify Holding B.v.

Koninklijke Philips Corporation N.v.

Philips Lighting Holding B.v.

Bernhard Christiaan Van Dijk

Haimin Tao

Paul R Veldman

Borong Su

Bernd Ackermann

Georg Sauerlaender

William Peter Mechtildis Marie Jans

Henri Arnoud Ignatius Melai

Johan Anton Hendrikx

Sanbao Zheng

Jianjun Yu

Zhihua Song

Paul Robert Veldman

A Direct Current, DC, voltage source arranged for providing a DC voltage based on an input voltage between two input terminals, wherein said DC voltage source comprises a transformer arranged for receiving a supply current, at a first side of the transformer, and for transforming said supply current to a circulating current at a second side of the transformer, a first and a second input terminal for receiving an input voltage for setting a DC voltage to be provided by said DC voltage source, a first diode, wherein an anode of said first diode is connected to a first end of said second side of said transformer, and wherein a cathode of said first diode is connected to said first input terminal, a current regulator circuit for assuring that an amount of current circulating current is shunted from the first diode.

Direct current, DC, voltage source arranged for providing a DC voltage based on an input voltage as well as a corresponding method

A switch mode power converter comprises an inverter, a transformer having a primary side winding and a secondary side winding and a first inductor in series with the primary side winding. A second inductor is provided magnetically coupled to the first inductor, and a voltage at one end of the second inductor is used as a feedback signal for indirectly measuring (i.e. approximating) the secondary side voltage, but with measurement at the primary side.

Switch mode power converter

A circuit is for generating a DC voltage supply from a higher voltage AC signal. A first capacitor (C) is in series between an input () and a first node (N), a first diode (D) is in forward direction between the first node and a DC voltage supply node (Nout), a second capacitor (C) is between the DC voltage supply node and a reference terminal, and a second diode (D) is in forward direction between the reference terminal and the first node. This defines a general charge pump architecture. A third capacitor (C) is then provided between the first node and a second node (N) and a controllable voltage supply () defines the voltage at the second node (N). This adjustable node voltage improves the efficiency of the circuit, in that excess current can be dissipated efficiently, and it can be implemented with a simple circuit.

Circuit for generating a DC voltage supply and a driver circuit using the DC voltage supply circuit

The present invention relates to an LED retrofit lamp () for being connected to a high frequency electronic ballast (), the high frequency electronic ballast () being adapted for providing a voltage and a current to the LED retrofit lamp (). The LED retrofit lamp () comprises an LED unit (), an adapting unit () for adapting the voltage and the current provided by the high frequency electronic ballast () to a voltage and a current for operating the LED unit (), a detecting unit () for detecting an electrical value that depends on the current provided by the high frequency electronic ballast (), and a ballast protection unit () for performing, in dependence of the detected electrical value, an operation for protecting the high frequency electronic ballast () from an overcurrent situation. This allows avoiding an unsafe situation, such as when the high frequency electronic ballast () is overheated.

LED retrofit lamp having active over-current protection circuit

An apparatus (A,B,C,D,A,B,) supplies power to an output thereof. The apparatus includes: an isolation transformer () and a rectifier (). The isolation transformer has a parasitic capacitance (Cp) between one of its input terminals (S/F) and one of its output terminals (S/F). The rectifier has a pair of input terminals connected to the output terminals of the isolation transformer, and a pair of output terminals connected across the apparatus' output. The rectifier includes a plurality of diodes (D/D/D/D) connected in a bridge. The apparatus also includes a compensation device for compensating for an increase in an output voltage across the output of the apparatus due to a charge pump effect of the parasitic capacitance. The compensation device includes at least one compensation capacitor () connected across one of the diodes of the bridge.

Charge pump effect compensation for high frequency isolation transformer in lighting device power supplies

An LED replacement lamp () is described. An LED lighting assembly () comprising LED lighting elements is electrically connected to filament emulation circuits, connected to electrical contacts at each of two opposite ends () of an elongated member. The filament emulation circuits () each comprise a first resistor circuit () and a second resistor circuit () connected to first and second electrical contacts (). The first and second resistor circuits () are connected to the LED lighting assembly () at a common terminal (). In order to provide an LED replacement lamp for safe operation even in cases of component failure, and if the replacement lamp () is used in incorrect wiring configurations, the first and second resistor circuits () each comprise a series connection of at least two resistors, in such a way that in case of failure of one of the resistors, the total resistance of the filament emulation circuits () remains above a determined resistance value.

LED replacement lamp for safe operation under fault condition

The present invention relates to an LED retrofit lamp () adapted for operation with an alternating current. The LED lamp comprises an LED unit (), a mains current line, first and second switching devices () (e.g., first and second relays), and a control unit (). The control unit () detects an ignition voltage on the mains current line. In response to detecting the ignition voltage on the mains current line, the control unit () sets the first and second switching devices () to a conducting state such that the LED unit () is connected to power. By using the first and second switching devices (), safety of the LED lamp () is improved, in particular when installing the lamp () into a fixture designed for fluorescent lamps.

LED retrofit lamp

The present invention relates to an LED retrofit lamp adapted for operation with an alternating current. The LED lamp comprises an LED unit, first and second switching devices (e.g., first and second relays), a startup voltage supply unit () coupled in parallel to the first switching device, an ignition detection unit () coupled in parallel to the second switching device, and a switch drive unit () for setting the first and second switching devices to a conducting state. If one of the first and second switching devices is shorted either no startup supply voltage or no detection signal is provided, such that the failure is indicated externally to a user.

In an up-converter supplied by the mains supply and operating in the critical mode, the on-time of the switching element () is modulated so that it is increased in the vicinity of the zero crossings of the mains supply voltage. As a result the THD is lowered.

Circuit arrangement

In a bride circuit comprising a lamp choke that might partially saturate during the ignition of the lamp, at least one of the switches is switched off when the amount of charge displaced through it in forward direction equals a predetermined value. Despite the partial paturation of the lamp choke the amplitude of the ignition voltage is thereby effectively controlled.

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Geldrop, Netherlands

Bernhard Christiaan Van Dijk