| 摘要 |
PROBLEM TO BE SOLVED: To provide an inverter circuit of separate excitation type which can respond to the difference of impedance before the operation start and after the operation start of a cold cathode lamp and therefore, can control stably throughout before operation start and after operation start, and furthermore, can drive a drive object with characteristics deviations, for example, a cold cathode lamp, without accompanying design changes and adjustments of characteristics of a resonance element. SOLUTION: The resonance frequency is made to be switched over at a starting time and a normal operation time, and the frequency of the starting time is made higher than that of the normal operation time. The resonance frequencies at the starting time and the normal operation time are respectively established at the values outside the allowable range of variations due to impedances of the cold cathode lamps 18, 18 of the resonance frequencies at the time of non-operation and at the time of normal operation of the resonance circuit on secondary side. COPYRIGHT: (C)2010,JPO&INPIT |
