A ballast for powering a lamp at deep dim levels. Driving circuitry includes a feedback loop which compares a desired dim level to a signal representing actual lamp power consumption. The loop is closed once the signal representing actual lamp power consumption equals the desired dim level. During...http://www.google.fr/patents/US5680017?utm_source=gb-gplus-shareBrevet US5680017 - Driving scheme for minimizing ignition flash
