Patent ID: 10528072

Abstract:
An input voltage control device including a first power line inputted with a voltage of 300V to 380V and a second power line inputted with a voltage of 0V. The potential difference between the first power line and the second power line is variable. A constant voltage generator outputs a constant potential voltage of (24V, for example) to a third power line. A reference potential generator outputs a reference potential of (10V, for example). A comparative potential generator outputs a comparative potential which is within the range of (0V to 24V, for example), based on the input voltage. A comparator outputs to an NMOS transistor a conducting potential voltage of (24V, for example) or an interrupting potential voltage of (0V, for example) depending on the comparison between the reference potential and the comparative potential. When the comparator outputs the conducting potential, the path between the source and drain of the NMOS transistor is made conductive. When the comparator outputs the interrupting potential, the path between the source and drain of the NMOS transistor is made non-conductive.