| 摘要 |
PURPOSE:To prevent destruction of an electronic device and a circuit against a negative surge voltage by adopting the configuration such that a power is supplied from a system power supply to the electronic device and the circuit through an integration circuit. CONSTITUTION:When a negative lightening surge voltage is applied to terminals A, B, a surge current flows from a system power supply VBB to terminals B, A through a diode bridge 6 and a protection resistor RP. In this case, a momentary voltage drop is caused in the power supply VBB due to a parasitic inductance in the circuit, a steep change in the amplitude of the power supply VBB is relaxed by an integration circuit 30 and the resulting voltage is fed to an electronic device/circuit 20. Thus, destruction of the circuit 20 is prevented even when a lightning surge of negative is impressed to the circuit 20. |
