| 摘要 |
PROBLEM TO BE SOLVED: To provide a partial resonance PWM inverter capable of surely performing zero-voltage switching in a short zero-voltage period. SOLUTION: This inverter is provided with first and second main switching elements Q1 , Q2 , a first free wheeling diode G1 and a first capacitor for resonance C3 connected in parallel with the first main switching element Q1 , and a second free wheeling diode G2 and a second capacitor for resonance C4 connected in parallel with the second main switching element Q2 . First and second auxiliary switches Sa, Sb and a reactor for resonance L2 are connected between the intermediate junction of the first and second main switching elements Q1 , Q2 and a divided voltage outputting terminal where the half of a DC source voltage is outputted. Here, a drive circuit 40, 50 is provided for comparing both the terminal voltage of each of the first and second main switching element Q1 , Q2 with a preset reference voltage, to turn on that switching element Q1 , Q2 , when the both terminal voltage becomes the reference voltage or lower, and to make this on-state maintained. |
