Driver for a solid state lamp

Driver for a solid state lamp having a nominal rating (IN;

• PN) corresponding to a nominal light output (LN), the driver having output terminals for connection to the lamp and having input terminals for receiving phase-cut AV supply voltage (PCACV);
• wherein the driver is designed to generate at its output terminals a lamp current for the lamp such that the lamp is operated at a dimmed light output (LA) with a dim factor (β=LA/LN) within a range between a minimum value (βMIN) and a maximum value (βMAX) on the basis of the phase angle (φ) of the phase-cut AV supply voltage (PCACV);
• wherein the driver comprises a memory containing information defining a function (F);
• wherein the driver is capable of operating in a normal mode in which the driver is designed to monitor the supply voltage received at its input terminals to detect the momentary value of the phase angle (φ), and to calculate the momentary value of the dim factor (β) from the momentary value of the phase angle (φ) according to a formula β=F(φ), in which
• β indicates the dim factor,
• φ indicates the phase angle,
• and F indicates said function defined by information in said memory;
• wherein the driver is capable of operating in a learning mode in which the driver is designed:
• to monitor the supply voltage received at its input terminals to detect the momentary value of the phase angle (φ),
• to detect the lowest value (φMIN) assumed by the phase angle (φ),
• to detect the highest value (φMAX) assumed by the phase angle (φ), and
• to update the said information in said memory such that the momentary value of the dim factor (β) calculated from the momentary value of the phase angle (φ) according to said formula will be equal to the minimum value (βMIN) when the phase angle (φ) has it minimum value (φMIN) and will be equal to the maximum value (βMAX) when the phase angle (φ) has it maximum value (φMAX).