摘要 |
The present invention provides a method and circuit for accurately controlling heating of an electrode of a discharge lamp. According to the present invention a feedback voltage is generated. The feedback voltage is representative of an electrode voltage, in particular an electrode voltage when the discharge lamp is in a non-burning state, the electrode voltage then representing a heating voltage. The feedback voltage is compared to a predetermined reference voltage, which represents a desired heating voltage. The comparator generates and outputs an error signal representing a difference between the actual feedback voltage and the reference voltage. The error signal is supplied to a power supply circuit. The power supply circuit generates the alternating supply current corresponding to the error signal such that the electrode voltage is adjusted towards the desired heating voltage.
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