An ignition system for a high-frequency high-intensity discharge lamp system
of
a type used for location-lighting during filming or other entertainment venues
includes a transformer with a pair of secondary windings, each having a primary
winding closely interwound. The secondary windings, which are connected between
the steady-state power source and the discharge lamp, are wound for producing opposing
magnetic fields with substantial flux cancellation. The primary windings are wound
to produce voltage amplification and connected to an ignition circuit adapted to
produce high-voltage ignition spikes to turn on the discharge lamp. The system
also includes a resonant circuit between the steady-state power source and the
transformer. The ignition and resonant circuits are temporarily energized to produce
a voltage for igniting the lamp. The advantage of secondary windings with opposing
magnetic fields in that a sufficient turns ratio is present to allow the transformer
to operate effectively during ignition, while at the same time the opposing magnetic
fields result in a low impedance with a reduction in both heat and inductive loss
during steady-state operation of the lamp system.