HIGH FREQUENCY ELECTRONIC BALLAST FOR HIGH PRESSURE DISCHARGE LAMP

摘要

PROBLEM TO BE SOLVED: To provide a high frequency electronic ballast for a high pressure discharge lamp which is light-weight, is not likely to be affected by fluctuation of a supply voltage, and is capable of supplying mild electricity and prolonging a service life of the lamp irrespective of a kind of the lamp.;SOLUTION: This ballast comprises a filter circuit 1 and a rectifying circuit 2 of an alternating current power supply, a switching power supply circuit 3 for turning a pulsating power supply acquired by the rectifying circuit into a stable direct-current power supply for voltage fluctuation and load fluctuation, an input/output noise reducing circuit 4, a high frequency oscillator for lighting the high pressure discharge lamp with a high frequency, a frequency oscillation controlling part 6 for adjusting quantity of light or the like, and a circuit for stopping high frequency oscillation and preventing an overcurrent when a current generated from a secondary winding of a ballast choke coil 7 is larger than a certain value.;COPYRIGHT: (C)2003,JPO