| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide means capable of conducting a diagnosis of a diode for input line surge protection with high accuracy at low cost.SOLUTION: A current controller includes a switch 7 provided between a power supply 10 that supplies a voltage to a power supply line VCC ESD 12 and the power supply line VCC ESD 12, the power supply line VCC ESD 12 being connected to a ground line GND ESD 17 by a resistance 5. At a time of an open failure diagnosis for a diode 3, the switch 7 is set open, and a potential difference between a voltage of an input signal line IN 13 and the power supply line VCC ESD 12 is measured, thereby diagnosing whether an open failure occurs to the diode 3.</p> |
