| 摘要 |
PURPOSE:To provide a DC power supply equipment having an improved power factor, whereby the conducting angle of its AC input current can be augmented and the obstructions given to other electronic apparatuses and power transmission equipments by its rush current, power factor and higher harmonic distorted currents are eliminated, in a switching type DC stabilized power supply used for various electronic apparatuses. CONSTITUTION:In a DC power supply equipment, no smoothing filter following the rectifier for an AC power supply 1 is used. The feedforward switching operation relative to a transformer 4, which is achieved by a first switching element 5, and the flyback switching operation relative to a choke 8, which is achieved by a second switching element 17, are performed alternately with each other. Thereby, an AC input current always flows into the DC power supply equipment, and the conducting angle of the AC input current is augmented, and in its turn, the power factor of the DC power supply equipment can be improved. |
