Electronic method to improve the starting characteristics of direct current arc lamps
A series connected L-C resonant circuit is connected between a lamp electrode of a xenon arc lamp and chassis ground. The L-C circuit has the ability to store energy as well as act as an oscillator. Energized by an initial high voltage pulse to a xenon arc lamp, the L-C circuit extends the ‘tail’ of the initial high voltage pulse provided to ignite the xenon arc lamp with a train or series of high frequency oscillations, which gradually decay. This resonant ‘tail’ causes the plasma streamer in the lamp to remain in the ionized state for an extended time period, until current ramp to the lamp up occurs, resulting in highly reliable ignition of the xenon arc lamp.
1. A starting circuit for an arc lamp, the starting circuit comprising:
a series coupled L-C resonant circuit, a first end of said series coupled L-C resonant circuit connected between a first lamp electrode and a chassis ground; and
a source of a high voltage impulse, coupled to said first lamp electrode and said first end of said series L-C resonant circuit, wherein the high voltage impulse is configured to energize the L-C resonant circuit, thereby causing the L-C resonant circuit to extend a tail of said high voltage impulse with a series of high frequency oscillations, wherein the tail is configured to cause a plasma streamer to remain in an ionized state for period of time which is greater than a period of time said plasma streamer would remain in an ionized state without said series L-C resonant circuit, at least until a current ramp up occurs.
2. A method of starting a direct current xenon arc lamp, the method comprising the acts of:
connecting a series coupled L-C resonant circuit between a first lamp electrode and a chassis ground, wherein the series connected L-C resonant circuit is configured to store energy and act as an oscillator; and
energizing the series coupled L-C resonant circuit with an initial high voltage impulse, wherein the series coupled L-C resonant circuit is configured to extend a tail or end of the initial high voltage impulse with a plurality of high frequency oscillations, wherein the plurality of high frequency oscillations is configured to cause a plasma streamer in said xenon arc lamp to remain in an ionized state for an extended time until a current ramp up occurs.