| 摘要 |
PURPOSE:To protect the surging of a switching semiconductor element, to improve the switching further by using the energy and to prevent the malfunction of a main circuit due to a high level noise. CONSTITUTION:In a driving circuit provided with a 1st transformer 3 having a primary winding whose one terminal is connected to a DC power supply 6 via a current limit element 5, a secondary winding connected to the control terminal of a switching semiconductor element 1, and a positive feedback winding and a 2nd transformer 8 having a primary winding inserted in series in a main current path of the switching semiconductor element 1 and a secondary winding, a surge absorbing circuit 12 and a discharge element 14 connected in series are connected in parallel with the series connection of the switching semiconductor element 1 and the primary winding of the transformer 8 and a diode 13 is connected in a direction that a surge current flows to the surge absorption circuit 12 among the connecting point of the surge absorbing circuit 12 and the discharge element 14 and a connecting point of the secondary winding of the 2nd transformer 8 and the series connection of the switching semiconductor element 1 and the primary winding of the transformer 8. |
