| 摘要 |
<p>PURPOSE:To measure with reliability by utilizing the charge to be charged electrostatically by electrostatic induction to a metal plate placed at a definite distance from a high voltage part and constituting to sense the high voltage. CONSTITUTION:The metal plate 1 is placed at the definite distance from the high voltage part 4, a propeller-shaped metal body 2 is rotated by a motor 3 near in front of the metal plate 1 and the metal body 2 is short-circuited electrically by earth 8. Then the motor 3 rotate the metal body 2 at a constant speed and covers the metal plate 1 periodically two times per one rotation, and a voltage waveform takes a saw-tooth-wave having two fold frequency due to the charge of the metal plate 1. This signal wave is amplified by a high impedance amplifier 5 to be inputted to a comparator 6 and compared with a constant threshold voltage Et at the comparator 6 to be outputted as a square-wave of a constant amplitude. And measuring a duty ratio by means of a duty ratio measurement instrument 7, high voltage is thereby sensed. The reliable measurement is thus executed.</p> |
