| 摘要 |
<p>The invention relates to a circuit arrangement for operating a lamp (La), provided with ballast means (B) for generating a lamp current from a supply voltage, a memory (M) in which a relation between a number of temperature-dependent lamp parameters has been laid down, means (III, IV, Va, Vb) coupled to the memory for changing lamp operation in dependence on the temperature. According to the invention, the temperature-dependent parameters are the voltage across the lamp, the current through the lamp, and the luminous flux of the lamp. The actual luminous flux of the lamp is determined by means of the memory through a measurement of the voltage across the lamp and the current through the lamp. The luminous flux of the lamp can be controlled to a substantially temperature-independent and substantially constant level in that this actual value of the luminous flux is used as a signal in a control loop, with the exclusive use of electrical parameters.</p> |
