| 摘要 |
PURPOSE:To provide a protective circuit of lighting system for automobile which has a long lamp life and a low cost. CONSTITUTION:In this protective circuit of lighting system, a power source 10, a load 20, a driving circuit 30, a voltage detecting circuit 40, a switching circuit 50, a PWM control circuit 60, and a fixed duty circuit 70 are provided, and when the power source voltage is less than a standard value, the driving circuit 30 is operated according to the signal of the PWM control circuit 60, and when the power source voltage exceeds the standard value, the driving circuit 30 is operated according to the signal of the fixed duty circuit 70. |
