| 摘要 |
PROBLEM TO BE SOLVED: To increase the efficiency of a switching power supply while ensuring a power factor and also secure the holding time and eliminate a ripple. SOLUTION: In an AC-DC converter- or inverter-method lighting equipment, a first switching transformer 104 or choke coil which uses the first power obtained by rectifying AC power into less smoothed power is operated by means of a switching means, a second switching transformer 108 or choke coil which uses part of the energy obtained by operating the first switching transformer or choke coil by means of a switching means and/or the second power which is obtained by rectifying AC power by means of a second rectifier into well smoothed power are switched by means of the switching means, and the outputs of the first and the second switching transformer or choke coil are combined. By this method, the efficiency, a power factor, and the holding time can be improved and a ripple can be eliminated and the size and the cost of the equipment can be reduced. Furthermore, by using a parallel combination of an output circuit of a flyback converter and that of a forward converter, a transformer of a high efficiency can be used and control can be done more easily. |
