| 摘要 |
PURPOSE:To reduce the switching loss and the noise of the titled device by a method wherein the currents of switching transistors are made to a sine wave form utilizing resonance action of a coil and a capacitor. CONSTITUTION:When the switching transistor 3 is made to ON, an input voltage is applied to a winding 12, and a voltage is induced in a winding 13. As a result, a resonance curent flows into the capacitor 15 according to resonance action of the coil 14 and the capacitor 15. When the transistor 3 is made to OFF, and the transistor 18 is made to ON next, electric charge of the capacitor 15 is discharged to the capacitor 8 according to resonance action with the coil 17. Because the currents to flow in the respective transistors 3, 18 become to the sine wave type, noise to be generated is limited to a fundamental wave. Moreover the currents of the transistors 3, 18 are zero at turn-ON time and turn-OFF time, no switching loss is generated, and no surge current is generated also. |
