Patent ID: 8779677
Filing Date: 2014-07-15
Classification: G03B,H05B

Abstract:
1. A circuit arrangement for operating a light source, in particular, a light-emitting diode, comprising: a first adjustable current path, that connects a terminal for a battery to a terminal for a capacitor; a second adjustable current path, that connects the terminal for a capacitor to a terminal for a light source; a third adjustable current path that connects the terminal for a battery to the terminal for a light source; a control unit, that has a control input and is set up to adjust respective current intensities on the first, second and third current paths as a function of the control signals that can be applied to the control input; and a first DC-DC converter, that is coupled to the terminal for a battery in such a manner that the first and third current paths comprise the first DC-DC converter, and that is controllably connected to the control unit by a control line, wherein the first DC-DC converter has a load current transistor that couples the terminal for a battery to the terminals for a capacitor and for a light source by means of its load side and is connected to the control unit by its control side, and has a charging current transistor, wherein the terminal is connected in series by its load side to a charging current measuring unit and the control unit, and the charging current transistor is connected by its control side to the control unit.