Koninklijke Philips Corporation N.v.

Signify Holding B.v.

Philips Lighting Holding B.v.

Philips Intellectual Property & Standards Gmbh

William Peter Mechtildis Marie Jans

Reinhold Elferich

Johannes Hubertus Gerardus Op Het Veld

David Llewellyn John

Haimin Tao

Berend Jan Willem Ter Weeme

Bertrand Johan Edward Hontele

Theo Gerrit Zijlman

Gazi Akdag

Paul Johannes Marie Julicher

Mark Thomas Johnson

Harald Josef Günther Radermacher

Carsten Deppe

Georg Sauerländer

Andrea Giraldo

Erik Martinus Hubertus Petrus Van Dijk

Tijmen Cornelis Van Bodegraven

Bernhard Christiaan Van Dijk

Remco Los

Borong Su

Geert Florimond Gerard Depovere

Sebastiaan De Bont

Erik MartinusHubertus Petrus Van Dijk

David Liewellyyn John

Patrick John Zijlstra

Georg SAUERLÄNDER

Various improvements are provided to resonant DC/DC and AC/DC converter circuit. The improvements are of particular interest for LLC circuits. Some examples relate to self-oscillating circuit and others relate to converter circuits with frequency control, for example for power factor correction, driven by an oscillator.

DC/DC resonant converters and power factor correction using resonant converters, and corresponding control methods

A half bridge resonant converter comprises a half bridge inverter having a high side switch and a low side switch with an output defined from a node between the high side switch and the low side switch. The output connects to a resonant circuit. There are separate control circuits for generating the gate drive signals for controlling the switching of the high side switch and low side switch, in dependence on an electrical feedback parameter, each with different reference voltage supplies.

Half bridge resonant converters, circuits using them, and corresponding control methods

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

The invention relates to LED replacement lamp suitable for operation with a high frequency fluorescent lamp ballast, comprising&#x2014;a LED load (LS) comprising a series arrangement of LEDs, &#x2014;a first lamp end circuit comprising&#x2014;a first lamp pin (LP) and a second lamp pin (LP) for connection to a first lamp connection terminal comprised in the high frequency fluorescent lamp ballast, &#x2014;a first rectifier (D-D; D, D) equipped with at least one input terminal coupled to the second lamp pin and with first and second output terminals coupled to respective ends of the LED load, the first rectifier comprising at least two diodes, one of which is shunted by a first capacitor (C), &#x2014;a second lamp end circuit comprising&#x2014;a third lamp pin (LP) and a fourth lamp pin (LP) for connection to a second lamp connection terminal comprised in the high frequency fluorescent lamp ballast, &#x2014;a second rectifier (D-D, D, D) equipped with at least one input terminal coupled to the fourth lamp pin and with first and second output terminals coupled to respective ends of the LED load, the second rectifier comprising at least two diodes, one of which is shunted by a second capacitor (C), wherein the first capacitor and the second capacitor form a series arrangement coupled between the second lamp pin and the fourth lamp pin.

LED retrofit lamp with shunt capacitors across rectifier diodes for use with a ballast

A driver circuit includes: a rectifier for exchanging a first current signal having a first frequency with an active fluorescent ballast, and for supplying a second current signal to a load which includes at least one light emitting diode; a switch circuit coupled to or forming part of the rectifier and configured to control an amount of power supplied to the load; and a controller configured to control the switch circuit. The switching frequency of the switch circuit is less than or equal to twice the first frequency. The controller is configured to synchronize the switching frequency of the switch circuit and the switching frequency of the active electronic ballast, which is equal to the first frequency.

Driver circuit between fluorescent ballast and LED

A lighting device has a plurality of LEDs of at least two types connected in series. At least one of the LEDs of the first type and LEDs of the second type is connected in parallel to a resistor assembly, such that the temperature-dependent resistance of the resistor assembly stabilizes a ratio of luminous flux output at different junction temperatures of the LEDs.

LED lighting device with temperature dependent output stabilizer

In a lighting device, sets of LEDs are employed using the natural characteristics of the LEDs to resemble incandescent lamp behavior when dimmed, thereby obviating the need for sophisticated controls. A first set of at least one LED produces light with a first color temperature, and a second set of at least one LED produces light with a second color temperature. The first set and the second set are connected in series, or the first set and the second set are connected in parallel, possibly with a resistive element in series with the first or the second set. The first set and the second set differ in temperature behavior, or have different dynamic electrical resistance. In various embodiments, the sum of the currents provided to the first and second sets may be substantially equal to a magnitude of an input current.

LED lighting device with incandescent lamp color temperature behavior

The present invention relates to an LED lamp () adapted for operation with an alternating current. The LED retrofit lamp () comprises a LED unit ('&#x2033;) and a compensation circuit with a controllable switching device (&#x2032;), connected parallel to said LED unit (&#x2032;&#x2033;) to provide an alternate current path. A control unit (&#x2033;) is adapted to control said switching device (&#x2032;) in a compensation mode in which said switching device (&#x2032;) is set to the conducting state for the duration of a shunt period in each half cycle of the alternating current to allow adapting the power/current of the inventive LED lamp (), so that a versatile and optimized operation of the lamp () is possible.

LED retrofit lamp

An electric lamp () has two pairs of external connection pins () adapted for connecting the lamp to a voltage source for powering an internal lighting module (). Each pair of pins is disconnected from the lighting module by an open switch () unless a non-zero electric voltage is applied to the pair and causes the switch to close. The lamp is therefore safe to handle even in a condition where one pair of pins is connected and the other is not. The lamp may be fitted in a switch-start fixture, providing an ohmic connection between two pins in different pairs, as well as a rapid-start fixture, with a capacitive connection.

Tubelamp retrofit pin safety implementation using existing ballast and fixture

In a lighting device, sets of LEDs are employed using the natural characteristics of the LEDs to resemble incandescent lamp behavior when dimmed, thereby obviating the need for sophisticated controls. A first set of at least one LED produces light with a first color temperature, and a second set of at least one LED produces light with a second color temperature. The first set and the second set are connected in series, or the first set and the second set are connected in parallel, possibly with a resistive element in series with the first or the second set. The first set and the second set differ in temperature behavior, or have different dynamic electrical resistance. The light device produces light with a color point parallel and close to a blackbody curve.

LED lighting with incandescent lamp color temperature behavior

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Eindhoven, Netherlands

William Peter Mechtildis Marie Jans