| 摘要 |
PROBLEM TO BE SOLVED: To provide a power unit from which higher harmonics are reduced. SOLUTION: A nonsmoothing power source 3 having a first capacitor C1 for nonsmoothing is connected to commercial AC power supply (e) through a full-wave rectifier circuit 2 and an inverter circuit 4 having a parallel resonance circuit 5 is connected to the power source 3. In the resonance circuit 5, a first auxiliary capacitor C2 and a diode D5 are connected to the primary winding Tr1a of an inverter transformer Tr1, and a main capacitor C3 is connected in parallel with the winding Tr1a. A transistor Q1 is connected in series with the circuit 5, and diodes D6 and D7 are connected in parallel with the first capacitor C1 connected with a partially smoothing circuit 7 through the diode D5 and, at the same time, a choke coil L1 and a capacitor C4 are connected to the capacitor C1. Moreover, the filaments FL1 and FL2 of a fluorescence lamp FL are connected to the secondary winding Tr1b of the transformer Tr1 through a ballast L2 and, at the same time, a capacitor C5 for starting is connected to the winding Tr1b. |
