U.S. Philips Corporation

Koninklijke Philips Corporation N.v.

Signify Holding B.v.

Johannes M Van Meurs

Adrianus M De Bijl

Pieter J Bolhuis

Marcel Beij

Paul R Veldman

Mark Johannes Antonius Verhoeven

Cornelis Antonius Verbakel

Machiel A Hendrix

Aleksandar Sevo

Jerzy Janczak

Karnekumar Arulandu

Nicolaas H Pol

Bernardus J Overgoor

Zhipei Wang

Dorota Barbara Pawelek

Jozef H Reinaerts

Huan Zhang

The invention provides a holder for snap-fitting a thermal fuse to an electronic component, wherein the holder comprises: a bottom surface for mounting the holder to a carrier comprising the electronic component, wherein the bottom surface comprises an opening for accommodating the electronic component; a first wall parallel to a second wall, wherein the first wall and the second wall each comprise a protrusion for snap-fitting the thermal fuse to the electronic component; a third wall, wherein the third wall comprises an edge for bending around at least one lead of the thermal fuse, wherein a shortest distance between the bottom surface and said edge is larger than a shortest distance between the bottom surface and one of said protrusion.

Holder for snap-fitting a thermal fuse to an electronic component

A lighting unit which includes a driver, a light source and a buffer capacitor of an auxiliary circuit (such as an independent active electronic circuit). The charging current allowed to flow to the buffer capacitor is controlled based on sensed currents flowing to the light source thereby to control the charging current of the buffer capacitor. In this way, large inrush currents caused by the use of a large buffer capacitor at the output of the driver can be avoided and the triggering of a fault detection mode within the driver can be prevented. Furthermore this circuit ensures that the driver is operated within the specification limits during start-up.

Lighting unit and driving method

A high frequency driver for a gas discharge lamp is supplied with a DC voltage. The driver converts the input DC voltage to an AC voltage and supplies the AC voltage to a load, which comprises a gas discharge lamp, an inductor connected in series with the lamp and a capacitor connected in parallel to the lamp. The AC voltage has a first high frequency during ignition of the lamp and a second high frequency during normal operation of the lamp after its ignition. The first frequency is higher than the second frequency by a ratio of at least 2.2. By modulating the frequency of the AC voltage the ratio can be increased while still complying with EMI and RFI requirements.

High frequency driver for gas discharge lamp

An electric circuit for igniting a discharge lamp includes a voltage source, and at least one condenser electrically connected to the voltage source. Further, a series chain is provided, electrically connected in parallel with the condenser, of at least one ignition and at least one inductor. A discharge lamp is electrically connected in parallel with the ignition.

Electric circuit for igniting a discharge lamp, and electric component module and discharge lamp incorporating such an electric circuit

A circuit arrangement for igniting and operating at least two discharge lamps. the circuit is provided with input terminals (K1,K2) for connection to a supply voltage source and a circuit I (SC, S1, S2) coupled to the input terminals for generating a high-frequency voltage from a supply voltage delivered by the supply voltage source. A load branch B is coupled to the circuit I and comprising a first branch A including first terminals (K3,K3') for accommodating a discharge lamp and a first inductive element L1, and a second branch C shunting the first branch A and comprising further terminals (K4,K4') for accommodating a discharge lamp and a second inductive element L2 which is magnetically coupled to the first inductive element L1. A circuit II limits the voltage across branch A and branch C to a first value during the ignition of the discharge lamps. A circuit III limits the voltage across branch A and branch C to a second value after the ignition of one of the discharge lamps thereby preventing the occurrence of ignition voltages of very high amplitude across the discharge lamp igniting last.

Discharge lamp circuit which limits ignition voltage across a second

A circuit arrangement for operating a discharge lamp having a load branch provided with lamp connection terminals and coupled to a branch of a DC-AC converter. The branch of the converter includes at least one switching element for generating and supplying a current of alternating polarity to the load branch by being alternately conductive and non-conductive at a frequency f. A drive circuit makes the switching element alternately conductive and non-conductive at the frequency f. A control circuit is coupled to the drive circuit and to the discharge lamp for generating a control signal which is dependent on the lamp current and serves to influence the frequency. The control signal is also dependent on a signal S which is a measure of comparatively rapid changes in the power consumed by the discharge lamp. The lamp power thus can be adjusted over a wide range irrespective of the type of discharge lamp used.

Electronic ballast circuit with lamp dimming control

The invention relates to a circuit arrangement for operating a discharge lamp, comprising a DC-AC converter provided with a switching element for generating a current whose polarity changes with a frequency f, a current sensor (SE), a drive circuit (III) for generating a drive signal to make the switching elements alternately conducting with the frequency f, a measuring circuit (I) coupled to the current sensor and having at least one switching element for generating a control signal which is dependent on a phase difference between a voltage across the load circuit B and a current through the load circuit B and on a second signal which is a measure for a minimum required phase difference, and a control circuit (II) for effecting a change in an operating condition of the DC-AC converter, this change being dependent on the control signal.

Circuit arrangement

An electric arrangement for igniting and supplying a gas discharge lamp (13) has two input terminals (1, 2) intended to be connected to an AC power supply source. The output terminals of a rectifier bridge (4, 5, 6, 7) are connected in the operative state of the lamp to a DC/AC converter having two input terminals (A, B), one terminal (A) of which is connected to the other terminal (B) at least via a series arrangement of a first semiconductor switching element (9) and a load circuit comprising at least an induction coil (10) and the discharge lamp (13) as well as a capacitor (15). The load circuit and capacitor are shunted by a circuit comprising a second semiconductor switching element (16) and a parallel arrangement of a third semiconductor switching element (18) and a diode (17). The first two semiconductor switching elements are shunted by a buffer capacitor (8). The third semiconductor switching element (18) includes a control circuit which makes the third switching element conduct for a given period at the start of each period of the high-frequency cycle of the converter.

Electric arrangement for igniting and supplying a gas discharge lamp

A DC/AC converter for igniting and supplying a gas discharge lamp (1). The converter has two input terminals (C, D) intended to be connected to a DC voltage source, said input terminals (C, D) being connected together by means of a series arrangement including a load circuit comprising at least an induction coil (10) and a parallel arrangement of the lamp and a capacitor (12), as well as a first semiconductor switching element (13). The load circuit is shunted by a circuit comprising a second semiconductor switching element (14). The semiconductor switching elements (13, 14) are rendered alternately conductive and non-conductive by means of control circuits (13a, 14a). A second capacitor (11) is arranged in series with the induction coil (10) and the lamp. The second capacitor is shunted by a third switching element (15) which is non-conductive during the pre-heat period of the lamp electrodes (2, 3) and is conductive at least during ignition of the lamp.

DC/AC converter for igniting and supplying a gas discharge lamp

An electric arrangement for igniting and supplying a gas discharge lamp (1). The arrangement is connected to an alternating voltage source and comprises a rectifier bridge (7) connected to a DC/DC converter provided with a rectifier element (11), a coil (10) and a high-frequency switched semiconductor switching element (12) coupled to a drive circuit. The DC/DC converter is connected to the input terminals (16, 17) of a high-frequency DC/AC converter incorporating the lamp and provided with semiconductor switching elements (21,24). A capacitor (15) is arranged between the input terminals of the DC/AC converter and a sensor (22) for measuring the converter current is arranged between one of the input terminals (17) and a semiconductor switching element (21) of the DC/AC converter. The lamp is connected in series with a frequency-dependent impedance 20. A drive circuit (13) of the semiconductor switching element in the DC/DC converter is coupled to a control circuit (14) and is also coupled to the capacitor (15). The voltage across the capacitor (15) is set to a desired value by adjusting the frequency and the period of conductance of the semiconductor switching element (12). The sensor (22) is coupled to a second control circuit (27) which is connected to the drive circuits (21a, 24a) of the semiconductor switching elements (21, 24) of the DC/AC converter whereby the frequency and/or period of conductance of the switching elements of the DC/AC converter, and hence the power consumption of the lamp, can be regulated.

Circuit for supplying constant power to a gas discharge lamp

A DC/AC converter for igniting and supplying a gas discharge lamp (1) has two input terminals (C, D) intended to be connected to a DC voltage source. These input terminals are connected together by means of a series arrangement of a load circuit comprising at least the discharge lamp (1) and an induction coil (8), as well as a first semiconductor switching element (9). This load circuit being shunted by a circuit comprising a second semiconductor switching element (10). The switching elements (9, 10) are rendered alternately conductive and non conductive at a high frequency. The lamp is shunted by a third semiconductor switching element (12) which is conductive while the lamp electrodes (2, 3) are being pre-heated, whereafter the converter is rendered inoperative for a short period of time in order to ignite the lamp, which time is shorter than the time required to cool the lamp electrodes to below their emission temperature. The converter is thereafter rendered operative again.

An electric arrangement for regulating the luminous intensity of at least one discharge lamp (15). The arrangement comprises an electric circuit having a first winding (110) arranged to surround a core (111) of magnetizable material. The winding (110) is included in a circuit forming part of a DC/AC converter for the supply of high-frequency energy to the discharge lamp. The core (111) is further provided with a second winding (112) and a third winding (118). The third winding is connected to a control device forming part of the converter. The third winding is magnetically coupled to the first winding. A series-combination of a non-capacitive variable impedance (115) and a diode (113) is connected between the ends of the second winding.

Electric arrangement for regulating the luminous intensity of at least

A DC/AC converter (30 to 72) for feeding a low-pressure mercury vapor discharge tube (15) comprises two series-connected main transistors (11 and 20) which, in the operating condition, are alternately conducting. The conduction times of the two transistors (11 and 20) are always kept equal to each other by means of an auxiliary circuit (70 to 72, 32a, 32b, 32c) which influences the operation of a timing circuit (32, 33). This prevents the occurrence cataphoresis in the lamp.

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Eindhoven, Netherlands

Johannes M Van Meurs