U.S. Philips Corporation

Koninklijke Philips Corporation N.v.

Johannes Hendrik Wessels

Ling Wang

Jacob Schlejen

Marcel Beij

Ihor T Wacyk

Arnold Willem Buij

Geert Willem Van Der Veen

Machiel Antonius Martinus Hendrix

Petrus H Antonis

Leonardus U Konings

Everaard Marie Jozef Aendekerk

Jozef R Bergervoet

Ronny A Jacobs

Jeroen Peter Balm

Andrianus M De Bijl

Johannes H Op Het Veld

Melanie Maria Jeanne Anna Michon

Franciscus Theodorus Backers

Herman Adrianus Godefridus Severinus Smulders

Arnold Willem Buji

A wireless control is provided for a lamp, such as a fluorescent lamp, controlled by a ballast with a wireless control interface for RF communication. The receiver input and the transmitter output of the control interface module are connected to one or more electrode wires by a coupling capacitor(s) or a Lecher line transformer. During operation the lamp electrodes serve as the lamp antenna.

Antenna through the use of lamp electrodes

A communication network includes a plurality of devices and a control unit for generating control signals to control the operation of the devices. Each device includes: a device operating circuit, a communication interface for receiving command signals for controlling operation of the devices, a control circuit coupled between the device operating circuit and the communication interface for controlling the operation of the device operating circuit part in dependency of said command signals, and a master integral to the device for receiving the control signals, for generating the command signals in response to the received control signals, and for transferring the command signals to the communication interfaces of the plurality of devices. The communication network activates one of the masters as an active master, and in case the active master fails, then it activates another master to take over as the active master.

Communication network with arrangement for replacing a malfunctioning active master with a new active master

A circuit drives an LED array and controls the brightness of the LED array by regulating the current flowing through the array. The LED array is driven by a pulse-shaped current of which the mean value is regulated with at least one or two of the following types of modulation: frequency modulation, pulse-width modulation, and amplitude modulation.

Switching device for driving LED array by pulse-shaped current modulation

A fluorescent lamp (), in particular a backlight lamp of a display device, is supplied with an alternating voltage, a frequency and an amplitude of which being greater during ignition than during normal operation of the lamp. The voltage (V) across the lamp and the current (I) through the lamp are measured to provide a measured voltage value and a measured real lamp current value. From the alternating voltage there is derived a voltage (V). The measured voltage value is multiplied by the sum of the measured real lamp current value and the derived voltage. The multiplication result (P=V*(I+V)) is compared with a reference value (Ref), which results in a difference or error value. The error value is used to control the frequency and the amplitude of the alternating voltage (V), such that the error value is minimized.

Power control of a fluorescent lamp

The invention is a new architecture for a high frequency (HF) ballast with wireless communication interface. The new architecture integrates the RF wireless interface into the ballast. A user control transmits an RF control signal to a second antenna at the ballast site which provides the RF signal to the ballast which activates the fluorescent lamp. The ballast includes a transceiver/receiver, a communication decoder, a power control stage and a power stage. The transceiver/receiver receives the RF signal and communicates it to the communication decoder which acts as an interface to the power stage control. The power stage control controls the power stage that activates the fluorescent lamp. The communication decoder, power control stage, power stage and transceiver/receiver are located within the ballast enclosure which is an important part of the invention. If the power stage control is digital it may be combined with the communication decoder into one microprocessor or digital controller such as an ASIC. The communication decoder may be a serial interface. The transceiver/receiver is an RF integrated circuit. The ballast further includes an isolator to isolate the transceiver/receiver from the first antenna. The isolator may be capacitive.

Architecture of ballast with integrated RF interface

An electronic ballast for operating a lamp with a high-frequency current is equipped with a load branch comprising two LC combinations. The LC combinations are dimensioned such that the shape of the high-frequency current is in between a sine shape and a square-wave shape. The efficacy of a lamp operated by means of the electronic ballast is high, while the RFI generated by the lamp is low.

Switching device

The light output of a lighting arrangement is adjustable at two levels by, for example, &ldquo;toggling&rdquo;. During a predetermined time interval immediately after ignition, the lamp is supplied with additional power to heat up. Immediately after stationary conditions have been reached, the light output is automatically adjusted to the lowest of the two levels. During the predetermined time interval, the light output is also controlled so as to be at the lowest of the two levels, so that relatively large changes in the level of the light output during the predetermined time interval, and immediately after it, are prevented.

Circuit device for dimming a discharge lamp

In a ballast circuit for operating a discharge lamp, two different lamp power levels are adjustable. The ballast circuit is equipped with a switch to optimize the amount of power feedback for the lamp power level. This enables total harmonic distortion and power balance to be optimized for more than one power level.

Circuit device for operating a discharge lamp by means of a high-frequency current

A circuit arrangement comprising a DC-AC converter for operating a lamp (La). A first capacitor is connected across first and second inputs of the DC-AC converter. A first coil and a second capacitor are connected in a series circuit to first and second outputs of a rectifier circuit coupled to an AC supply voltage. Two diodes are serially connected between the first output and the first input. A third capacitor is connected between a junction point of the two diodes and a junction point between two series connected transistors of the DC-AC converter. The diodes, the coil (L1) and the second and third capacitors (C2, C3) are so dimensioned that the resonance frequency of a series circuit of the coil and the second and third capacitors connected in parallel is approximately equal to the operating frequency of the DC-Ac converter. As a result, the circuit arrangement has a high power factor.

High frequency discharge lamp operating circuit with resonant power

An illumination unit comprises a high-frequency supply (1) and a low-pressure discharge lamp (2). The high-frequency supply (1) is provided with a first and a second output (13a, 13b). The outputs each deliver a HF-varying voltage with respect to ground. The voltages have the same magnitude and are in phase opposition. The supply (1) is provided with a further output (13c) which is substantially free of high-frequency voltage variations with respect to ground. The low-pressure discharge lamp (2) is provided with a tubular discharge vessel (20) with an ionizable filling. The discharge vessel comprises a first and a second external electrode (23a, 23b), which are arranged at opposite ends (24a, 24b, respectively) of the discharge vessel and which are connected to the first and the second output (13a, 13b) of the supply (1) and a further external electrode (23c) which is arranged centrally between the ends (24a, 24b) of the discharge vessel (20), said external electrode being connected to the further output (13c) of the supply (1). The measure results in a more uniform brightness distribution of the discharge vessel (20).

Illumination unit and liquid crystal display device

A circuit arrangement according to the invention for operating a discharge lamp (I) comprises a DC/AC converter (II) provided with a series circuit with a first and a second switching element, (1, 1', respectively) between a first and a second input terminal (5, 5', respectively) for connection to a DC voltage source, and with a starting circuit (F) with a first resistive means (R1) between the first input terminal (5) and the control electrode (2) of the first switching element (1). The DC/AC converter is also provided with a second resistive element (R2) which together with the first resistive element (R1) form a voltage divider between the input terminals (5, 5'). The power dissipation in the DC/AC converter is reduced thereby.

Circuit arrangement for operating a discharge lamp

An electrodeless low-pressure discharge lamp includes a translucent discharge-vessel of a glass that contains at least 5 weight % sodium, encloses a discharge-space and includes a mercury containing fill. The lamp further includes a device to maintain an electrical discharge in the discharge space and an auxiliary radiation source that emits at least 0.5 mW of visible radiation when activated, to provide a relatively short ignition time.

Electrodeless low-pressure discharge lamp

A circuit arrangement suitable for operating low-pressure mercury discharge lamp by means of a high-frequency current includes circuitry (I) for generating the high-frequency current from a supply voltage, and a modulator (II) for the substantially square-wave modulation of the amplitude of the high-frequency current at a modulation frequency f. The circuit arrangement is further provided with circuitry (V) for limiting the amplitude of the re-ignition voltage across the low-pressure mercury discharge lamp to a voltage Vi. As a result, interference with infrared systems caused by a discharge lamp operated by the circuit arrangement is substantially fully suppressed.

Modulated high frequency dimmer circuit with infrared suppression

A circuit arrangement for operating a discharge lamp (4). The circuit arrangement is provided with a DC-AC converter (3) and with a starter circuit (5) for starting the DC-AC converter. The starter circuit comprises a circuit (50, 52, 53) for generating starting pulses through the charging of a capacitor (50). The starter circuit also includes a discharge resistor (51) for discharging the capacitor, and a switching element for disconnecting and for keeping the starter circuit disconnected. The starter circuit thus can generate starting pulses in quick succession so that the luminous flux of the lamp is controllable over a wide range.

Circuit for controlling light output of a discharge lamp

A circuit arrangement comprising a DC/AC converter for supplying power to a lamp upon receiving energy from a DC voltage source; the converter includes a branch A having at least one switching element and a control branch connected to the switching element; the control branch comprises a coil shunted by a capacitor; the circuit arrangement also includes a load branch with an inductor connected to a parallel arrangement of an inductance and capacitance.

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Eindhoven, Netherlands

Johannes Hendrik Wessels