Osram Ag

Osram Gesellschaft MIT Beschraenkter Haftung

Yanshun Xue

Yilong Ye

Guoji Zhong

Markus Heckmann

Rene Twardzik

Wei Gao

Wei Chen

Junying Wang

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

Proposed is a circuit for driving a fluorescent lamp and a light-emitting diode. The circuit may include an inverter; a fluorescent lamp driving branch for driving a fluorescent lamp; a light-emitting diode driving branch for driving a light-emitting diode; a starting branch; and an alternate control branch. By using a simple circuit structure, various embodiments may realize a circuit capable of conveniently and alternately driving a fluorescent lamp and a light-emitting diode.

Circuit for driving fluorescent lamp and light-emitting diode

Provided is a circuit for detecting a filament of a fluorescent lamp, wherein a first end of a first filament is connected to a second end of the first filament via an oscillation circuit, and the first end of the first filament is connected to an output of an inverter; a first end of a second filament is connected to a second end of the second filament via an oscillation circuit, wherein the first end of the second filament is connected to an internal ground; the second end of the second filament is connected to a power source, and a voltage at the second end of the second filament is used for controlling ON and OFF of an MOSFET, wherein a source of the MOSFET is connected to the internal ground.

Filament detection circuit

Growing community of inventors

Guangzhou, China

Yanshun Xue