| 摘要 |
PURPOSE: To prevent a lamp from being extinguished even if an AC power supply voltage or circuit load is varied by employing a common connection point to two diodes connected in parallel to an inverter input side as an output side terminal of an inverter common to a load circuit and an electric efficient bridge capacitor. CONSTITUTION: A charging choke coil LK is provided in the connection path between one output side terminal of a rectifier GL and a common connection point of a diode DK and a sine-wave correction capacitor CB, and an AC power voltage un of a rectifier circuit GB is applied via a high-frequency filter FE to the coil LK. For an optimum restrictive action of clamp diodes DBS and DBL, an electric effective bridge capacitor CH is designed so as to have a value that the charging voltage thereof substantially follows a high-frequency load current. Thereby, even if the AC power voltage and/or load of the load circuit are/is varied, a fluorescent lamp is not extinguished, and the generation of an unallowable high frequency can be prevented. |
