DC converter with improved power factor

摘要

By the on and off operations of a MOS-FET 5, a current flows intermittently through a primary winding 10a of a choke coil 10 to induce voltage in a secondary winding 10b of the choke coil 10. A smoothing capacitor 3 can be charged during a wider period of time in a cycle of alternating current frequency due to a current flowing into the smoothing capacitor 3 by the sum of the rectified output voltage of a diode bridge rectifier 2 and the induced voltage in the secondary winding 10b of the choke coil 10 to improve the input power factor simply utilizing the primary and secondary windings 10a, 10b of the choke coil 10. A direct current converter can be made in small size and light weight due to the choke coil 10 of low inductance operated in high frequency and made in a small sized and light weight.