Ignitor-arrangement

A method of driving the high-intensity discharge lamp via an ignitor arrangement for a high-intensity discharge lamp, the ignitor arrangement comprising:

• a first pair of input terminals for applying an ignition voltage to the ignitor arrangement;
• a second pair of input terminals for applying an input drive voltage to the ignitor arrangement;
• an ignition capacitor;
• and
• a discharge resistor connected in parallel with the ignition capacitor and for discharging the ignition capacitor, the discharge resistor being arranged in an interior of the ignitor arrangement and connected across the first input terminal pair, the discharge resistor further being a temperature-dependent resistor having a resistance that depends on a temperature (T100) in the interior of the ignitor arrangement, wherein
• the first pair of input terminals comprises an ignition terminal that is not shared with the second pair of input terminals and is not used for the input drive voltage, the method comprising the steps of:
• connecting the high-intensity discharge lamp to the ignitor arrangement;
• applying the ignition voltage across the first pair of input terminals of the ignitor arrangement in order to ignite the high-intensity discharge lamp;
• applying, after ignition, the input drive voltage across the second pair of input terminals of the ignitor arrangement;
• determining the temperature (T100) in the interior of the ignitor arrangement, such determination comprising measuring a resistance of the temperature-dependent discharge resistor across the first pair of input terminals of the ignitor arrangement during a steady-state operation of the high-intensity discharge lamp;
• and
• regulating an operating power of the high-intensity discharge lamp on basis of the temperature (T100) in the interior of the ignitor arrangement.

A system including a lamp driver realized to drive a high-intensity discharge lamp via an ignitor arrangement, the lamp driver comprising:

• ignition circuitry realized to apply an ignition voltage across a first pair of input terminals of the ignitor arrangement to charge an ignition capacitor connected across the first pair of input terminals, the first pair of input terminals comprising an ignition terminal used during ignition of the high-intensity discharge lamp;
• drive circuitry realized to apply an input drive voltage across a second pair of input terminals of the ignitor arrangement, the second pair of input terminals not including the ignition terminal;
• a temperature evaluation unit realized to determine a temperature (T100) in an interior of the ignitor arrangement, such determination comprising measuring a resistance of a temperature-dependent discharge resistor during a steady-state operation of the high-intensity discharge lamp, and the temperature-dependent discharge resistor being arranged in the interior of the ignitor arrangement and connected across the first pair of input terminals of the ignitor arrangement and serving for discharging the ignition capacitor;
• and
• a control unit for regulating an operating power of the high-intensity discharge lamp on basis of the temperature (T100) in the interior of the ignitor arrangement.