| 摘要 |
PROBLEM TO BE SOLVED: To improve measurement accuracy and working efficiency by providing a first switch for selecting either of a pair of light-emitting diodes whose conduction directions are opposite to each other, and a second switch for connecting a lead wire for measurement to be connected to a measurement target. SOLUTION: First, a switch 9h is closed and a power supply is connected and then switches 9g and 9f are closed to sides (d) and (b), respectively. Then, since no current flows to power transistors 1-6, light-emitting diodes 9j, 9l, 9n, and 9p do not turn on. Then, when the switches 9g and 9f are closed to sides (c) and (b), respectively, current flows to the power transistors 2-6 and light-emitting diodes 9i, 9k, 9m, and 9o turn on. After that, when the switches 9f and 9g are closed to the sides (d) and (a), respectively, current flows to the power transistors 4-6 and the light-emitting diodes 9j, 9l, and 9n turn on. In this manner, since the diodes are turned on the off by switching the switches 9g and 9f, it can be judged whether the IPM(intelligence power module) of an inverter is good or not. |
