| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an inexpensive overvoltage measure circuit such that a protection element is not broken even when a wrong input voltage is applied.SOLUTION: An overvoltage measure circuit includes: a protection element which is adaptive to an assumed wrong input voltage higher than a rated input voltage; a first DC voltage generation circuit which generates a first DC voltage corresponding to an input voltage; a switching power circuit which converts the first DC voltage into a second DC voltage; a microcomputer which uses the second DC voltage as a power supply voltage; a third DC voltage generation circuit which generates a third DC voltage corresponding to the input voltage; and a notification part. The microcomputer determines whether the input voltage is the assumed wrong input voltage based upon the third DC voltage, and makes the notification part give notice of a determination result when determining that the input voltage is the assumed wrong input voltage. In addition to the solution for the problem to be solved, the notice can be given when the wrong input voltage is applied.</p> |
