| 摘要 |
PURPOSE:To prevent a fire and injuring a human body by preventing the on-duty of the output signal from exceeding a specific value even though a driving circuit generates a trouble or an error operation. CONSTITUTION:A driving circuit 1 to determine the on-duty of a switching element SW is provided. A protective circuit 2 to suppress the ON period of the switching element SW not to exceed a specific time is provided. When the driving circuit 1 generates a trouble, and the on-duty signal of the switching element SW is made larger than in the rating time, the protective circuit 2 detects it. The protective circuit 2 controls forcibly the ON period of the switching element SW so as not to exceed a specific time. |
