Device and method for providing power to gas discharge lamp

A method for providing an amount of power to a gas discharge lamp, the method comprising:

• from a cold start of the gas discharge lamp, supplying a maximum current to the gas discharge lamp;
• when the power to the gas discharge lamp reaches a maximum amount of power, supplying a decreasing current to maintain the power to the gas discharge lamp at the maximum amount of power;
• at a predefined time interval after the cold start of the gas discharge lamp, measuring a non-steady-state voltage value of a voltage signal across the gas discharge lamp;
• calculating the calculating a boundary voltage value as a function of the measured, non-steady-state voltage value of the voltage signal;
• and
• when the voltage signal reaches the boundary voltage value, supplying an even more decreasing current to decrease the power to the gas discharge lamp.

An electronic ballast for providing an amount of power to a gas discharge lamp, the ballast comprising:

• a supply circuit for supplying the power to the gas discharge lamp;
• a control circuit configured to:
• from a cold start of the gas discharge lamp, supply a maximum current to the gas discharge lamp;
• when the power to the gas discharge lamp reaches a maximum amount of power, supply a decreasing current to maintain the power to the gas discharge lamp at the maximum amount of power;
• at a predefined time interval after the cold start of the gas discharge lamp, measure a non-steady-state voltage value of a voltage signal across the gas discharge lamp;
• calculate a boundary voltage value as a function of the measured non-steady-state voltage value of the voltage signal;
• and
• when the voltage signal reaches the boundary voltage value, supply an even more decreasing current to decrease the power to the gas discharge lamp.