Patent Treuhand Gesellschaft Fur Elektrische Gluhlampen Mbh

Patent-treuhand-gesellschaft Fuer Elektrische Gluehlampen Mbh

Osram Gesellschaft MIT Beschraenkter Haftung

Osram Gmbh

Patent-treuhand-gesellschaft F&uuml;r Elektrische Gl&uuml;hlampen Mbh

Osram Gesellschaft MIT Beschrankter Haftung

Rene Twardzik

Markus Heckmann

Olaf Busse

Harald Schmitt

Wei Gao

Juergen Klier

Martin Grabner

Yanshun Xue

Richard Koeppl

Michele Tiso

Cristian Bahr

Fubing Xie

Ange Gao

Thomas Eckhard

Henry Hoo

Ken Liu

Jerzy Cierpinski

Bernhard Orben

Various embodiments may relate to a load driving circuit and an illumination apparatus including the same. The load driving circuit includes a Single-Ended Primary Inductor Converter (SEPIC) converter adapted to convert an input system voltage into a DC output voltage, and a BUCK converteradapted to regulate a current and provide the regulated current to a load. The load driving circuit further includes a first diode and a second diode which are connected so that the SEPIC converter and the BUCK converter share one switch. According to various embodiments, it is possible to obtain constant current output characteristics and high power factor with a simple circuit structure and a low cost.

Load driving circuit and illumination apparatus including the same

A casing for electronic ballast, in which a PCB assembly is received, may include: a top wall; a bottom wall opposite to the top wall; two opposite side walls extending integrally between the top wall and bottom wall; and two opposite end walls extending integrally from the top wall, wherein the top wall, bottom wall, side walls and end walls are formed integrally, the top wall, bottom wall and side walls define openings at both ends of the casing in a lengthwise direction of the casing, the end walls are arranged to be pivotable relative to the top wall so as to close the openings formed by the top wall, bottom wall and side walls.

Casing for electronic ballast

A detect method is provided for performing step dimming selection in an electronic ballast including an End of Lamp Life detect circuit and a half-bridge inverter, the End of Lamp Life detect circuit being connected to an input terminal of the control circuit, wherein each time when the power switch is turned on, it is judged whether the electronic ballast should enter the dimming mode or not by detecting the voltage at the input terminal of the control circuit before the half-bridge inverter starts operating.

Detect method for step dimming selection

Apparatus for safely connecting a lamp to an equipment voltage ground, includes a rectification circuit for rectifying the power supply alternating voltage into a direct voltage, and an oscillating circuit for converting the direct voltage into alternating voltage for driving the lamp to work. The oscillating circuit includes a DC-blocking capacitor, a oscillating inductor and an oscillating capacitor orderly connected in series, and one end of the DC-blocking capacitor is connected to the output rectification voltage of the rectification circuit, and another end is connected to the oscillating inductor, while one end of the oscillating capacitor is connected to the equipment voltage ground, and another end is connected to the working voltage terminal of the lamp. The ground terminal of the lamp is electrically connected to the equipment voltage ground through a parallel circuit formed of a switch and a high impedance capacitor.

Apparatus for safely connecting the lamp to the equipment voltage ground

The invention relates to circuit arrangements for operating lamps and to operating devices which contain such circuit arrangements. A first stage of a circuit arrangement according to the invention comprises a SEPIC known from the literature. The SEPIC provides a DC voltage which an inverter converts to a radiofrequency AC voltage for lamp operation. According to the invention, an electronic switch (S) acts both in the SEPIC and in the inverter. Two diodes (D, D), which are connected into the supply line for the electronic switch (S), prevent the SEPIC and the inverter from influencing one another.

Circuit arrangement and operating device for operating lamps

In a circuit arrangement for operating light sources, inexpensive technologies for power factor correction can be used in combination. Owing to the combination of a dual charge pump and a valley fill circuit it is also possible to adhere to relevant standards for rated current harmonics even at rated powers of over 25 W whilst maintaining low component loading.

Circuit arrangement for operating light sources

The invention relates to a ballast for operating at least one low-pressure discharge lamp, preferably a three- or four-lamp ballast. In order for all parallel- or series-connected low-pressure discharge lamps (L -L ) to shine equally bright even in the case of strong dimming, the ballast according to the invention has a transformer (Tr ) for balancing the currents in the lamp branch circuits and a transformer (Tr ) for compensating the losses owing to parasitic capacitances.

Ballast for operating at least one low-pressure discharge lamp

The invention relates to an coil former and at least one wire winding arranged on the coil former, the coil former (,) having a cylindrical sleeve (,) whose cylinder axis runs parallel to the winding axis (A&mdash;A) of the at least wire winding, and at least two side walls (,) arranged perpendicularly to the winding axis (A&mdash;A), and the cylindrical sleeve (,) and the side walls (,) forming at least one winding space for the at least one wire winding (,). According to the invention, the at least two side walls (,) each have at least one shoulder (,), which subdivide the at least one winding space into a non-constricted first region (B,) and into at least one constricted second region (B,). In addition, the inductance element has electrical insulation (,), which bears on the at least one shoulder (,) of the side walls (,) and separates the non-constricted first region (B,) from the at least one constricted second region (B,).

Inductance element

The electronic ballast has a rectifier arrangement (1)--which is fed by AC power supply voltage (U)--with active step-up converter (SW2), a storage capacitor (C2), a network for limiting an inrush current and two outputs, at which a stabilized DC voltage (U+) referred to housing ground as reference potential (Uref) is output. An inverter (2) is connected to the rectifier arrangement, a load circuit (3) with at least one fluorescent lamp (La1 and/or La2) being assigned to said inverter on the output side. The inverter has a converter network (T1/1, T1/2, C1, SW3, SW4), preferably designed as a push-pull circuit, with two bridge paths, which, in the steady-state operating condition, are alternatively switched through to the reference potential. In this case, the switching network for limiting the inrush current comprises a limiting resistor (R1), which, in series with the storage capacitor (C2), is connected to reference potential. The junction point between the storage capacitor and the limiting resistor is coupled to the two bridge paths of the converter network in such a way that it is connected, in the steady-state condition of the inverter, via the latter to housing ground and the limiting resistor, which is thus effective only in the switch-on phase, is bridged.

Electronic ballast with inrush current limiting

A switched-mode power supply for supplying a DC-fed load (LD) by a steppep, stabilized DC voltage (uzw), which is formed from an AC mains voltage (U) by means of a rectifier circuit (D1 to D4), a charging inductor (L1), a switch (V1), which is controlled by a control unit (2) and has its switching path connected in parallel with outputs of the rectifier circuit, and also a charge storage arrangement (D5, C1, C2, D6), which is connected once again in parallel with the switching path of the said switch. In this case, the charge storage arrangement (D5, C1, C2, D6) comprises a series circuit of charging diodes (D5 and D6) and two storage capacitors (C1, C2), whose common junction point is connected to a neutral conductor terminal (N) of the rectifier circuit. The charging inductor (L1) is arranged in the line path, at high potential (L), between AC mains voltage (U) and the rectifier circuit and has an auxiliary winding (L1s), to which a signal evaluation unit (3) for the floating evaluation of the instantaneous charge state of the charging inductor is connected, in order to derive therefrom state control signals (Ul1, Ust, Io) for the control unit (2).

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Traunreut, Germany

Rene Twardzik