Koninklijke Philips Corporation N.v.

Thijs Oosterbaan

Nicola Bettina Pfeffer

Joseph Franciscus Raymond Eijsermans

Marinus Cornelis Raas

Bernardus Lambertus Martinus Van Bakel

Dolf Henricus Jozef Van Casteren

Frans Slegers

Christofher Daniel Charles Hooijer

Roy Hendrik Anna Maria Van Zundert

Johannis Antonie Amerens Toonen

A color adjustable lamp may be controlled using a TRIAC dimmer circuit and includes a lamp driving circuit and two or more light sources. Each light source may output light having a different color. By setting an output intensity of each light source, light having a desired color may be output. A circuit or a processing unit of the lamp driving circuit may detect a set phase angle of the TRIAC dimmer circuit by determining a shape of the supplied alternating voltage. According to the determined shape, the circuit or processing unit controls a lamp driver circuit for each light source in order to control the intensity of the light output by each light source and set the color of the color adjustable lamp by adjusting the intensity of the light emitted by each light source.

Color adjustable lamp

An ignition circuit for igniting a gas discharge lamp generates a high voltage gas breakdown pulse by building up a current through a primary winding of a transformer. After a predetermined period and thus when a predetermined current flows through the primary winding, a capacitance is switched in series with said primary winding, thereby generating said high voltage gas breakdown pulse in a secondary winding of said transformer. After generating the high voltage pulse, the capacitance is short-circuited in order to preserve energy in the primary winding. The preserved energy is employed to build up energy again for a next high voltage pulse in a short time. At a high repetition rate and high voltage of the generated pulses, the ignition circuit according to the present invention is also suitable for driving the gas discharge lamp during a take-over period following the gas breakdown of the lamp for heating the lamp electrodes.

Multi-pulse ignition circuit for a gas discharge lamp

A color adjustable lamp may be controlled using a well-known TRIAC dimmer circuit. The color adjustable lamp comprises two or more light sources. Each light source may output light having a different color. By setting an output intensity of each light source, light having a desired color may be output. A circuit or a processing unit comprised in a lamp driving circuit may detect a set phase angle of the TRIAC dimmer circuit by determining a shape of the supplied alternating voltage. According to the determined shape, the circuit or processing unit controls a lamp driver circuit for each light source in order to control the intensity of the light output by each light source.

A circuit arrangement for operating a high pressure discharge lamp comprises a down converter equipped with an output capacitor and a commutator equipped with lamp connection terminals. The amplitude of the DC current generated by the down converter is controlled by means of a control loop. Commutation of the DC current causes a periodical voltage to be present across the output capacitor. This periodical voltage can be an overshoot voltage and/or a voltage caused by resonance of the lamp with the output capacitor. To suppress the periodical voltage, the reference signal of the current control loop is adjusted in dependency of the amplitude of the periodical voltage.

Growing community of inventors

Eindhoven, Netherlands

Thijs Oosterbaan