| 摘要 |
PURPOSE:To control the duty ratio of the driving signal or a switching element, which is obtained from a driving circuit using a pulse transformer and a clamping circuit, in a wide range. CONSTITUTION:A control signal 6 which has the duty ratio controlled and is obtained from a control circuit 2a has the frequency divided by a frequency dividing circuit 7 to obtain first and second control signals 81 and 82 where the high level period and the low level period are alternately arranged. First and second driving circuits 91 and 92 are synchronously controlled by these signals 81 and 82 to obtain first and second driving signals 101 and 102, and these signals 101 and 102 are synthesized by diodes D3 and D4 to generate a driving signal 3, and a switching element Q is driven. Consequently, the duty ratio is controlled in a wide range regardless of restrictions on the clamp voltage when first and second driving circuits consist of pulse transformers and clamping circuits having back electromotive forces of these pulse transformers, and the performance of the switching power conversion device is improved. |
