| 摘要 |
<p>PURPOSE: To obtain a voltage detector for switchgear in which the secondary circuit is reduced in size while stabilizing the output voltage by providing a guard electrode, while holding microgaps, on the outer circumferential part of an electrode and then grounding the guard electrode. CONSTITUTION: A disc electrode 12 is disposed oppositely to a main circuit conductor 11 and the electrode 12 is fixed with an insulated wire 14 connected with the secondary circuit. A doughnut-like guard electrode 17 is provided around the electrode 12 through a microgap and secured to a board wall 15 by means of upper and lower securing rods 18a, 18b and thereby it is set at the ground potential. The securing rod 18a is slightly thinner than the securing rod 18b and since it is slidable freely, the rate of electric line of force being interrupted is varied according to the position of the guard electrode 17. Consequently, output voltage can be controlled by regulating the height of the guard electrode 17 while fixing the capacitance of secondary circuit. Height of the guard electrode 17 can be regulated with low voltage because it depends on the static field.</p> |
