| 摘要 |
PURPOSE: To obtain a power conversion apparatus which prevents the life of a discharge lamp from being decreased by a method wherein, after the charging level of a second capacitor at an oscillation-frequency control means has been stabilized to a desired level, a pulse is generated in a pulse generation means by the charging voltage of a first capacitor at a time constant circuit and a main switching circuit is started. CONSTITUTION: When a commercial power supply 31 is turned on, a DC voltage is generated in a smoothing capacitor 33, a charging current flows into a second capacitor (CS) 57 via a resistance 34 and a diode 61, and the level of the CS 57 is raised. On the other hand, the charging current flows into a first CS 36 via respective resistances 34, 35, and the level of the CS 36 is raised. The CS 57 reaches a stable desired level, and the charging level of the CS 36 reaches the breakover voltage of a constant-voltage conducting element 51. The constant- voltage conducting element 51 is set to conduct, and an FET 39 is turned on. Thereby, an inverter circuit 37 is started, and a voltage to be applied to a fluorescent lamp 47 is generated after the potential of the CS 57 has been stabilized. As a result, the voltage does not become an abnormally large voltage. |
