Patent ID: 9095034
Filing Date: 2015-07-28
Classification: H01J,H05B,Y02B

Abstract:
1. A high frequency ballast for ignition and operation of a ceramic high intensity discharge (HID) lamp including an arc chamber and two capillaries each connected to the arc chamber at respective proximal ends of the capillaries, two electrodes each sealed within the capillaries by respective seals near the distal ends of the capillaries, wherein the electrodes extend from the seals through respective bores in the capillaries and protrude into the arc chamber at the proximal ends of the capillaries, the high frequency ballast comprising: an inverter circuit having output terminals; and an ignition circuit connected to said output terminals, wherein the electrodes are adapted to connect to said output terminals; wherein the ignition circuit is configured by said microprocessor to apply a plurality of pre-ignition voltage pulses to the electrodes; wherein the ignition circuit is configured by said microprocessor during the pre-ignition pulses to momentarily ignite the ceramic HID lamp and cause thereby significant current momentarily flow, wherein during said pre-ignition pulses an arc is produced substantially only between the proximal ends of the electrodes, wherein the ignition circuit is configured by said microprocessor to apply a final ignition pulse and to operate the lamp, only after the electrodes are sufficiently heated by said pre-ignition pulses to avoid arcing in the bores of the capillaries during the final ignition pulse.