| 摘要 |
PROBLEM TO BE SOLVED: To attain low noise by transferring energy stored in a charge storage capacitor to a charge supply transformer, and supplying the energy stored in the charge supply transformer to a power source during turn-off of a switching element. SOLUTION: An auxiliary switching element 13 turns on at turn-off of a switching element 3. During 1/4 of a resonance cycle of the electrostatic capacity of a charge storage capacitor 11 and the inductance of the primary winding of a charge supply transformer 12, the switching unit is turned on to transfer the stored energy of the charge storage capacitor 11 to the charge supply transformer 12. When the auxiliary switching element 13 turns off, the stored energy flows into a power source 1 through a charge supply diode 14, and when the energy stored in the charge storage capacitor 11 at the time of turning-on the switching element 3 is supplied to the power source during the off-period of the switching element. It is thus possible to suppress spike noise at the time of turning-on a reflux diode without increasing the loss.
|
