| 摘要 |
<p>PURPOSE:To miniaturize a device by making the end of a bar-shaped charge section arranged in the insulating gas hemispheroidal, forming an insulating layer on the hemispheroid and, at the same time, making the thickness of the insulating layer smaller than about 1/3 of an insulation distance from the hemispheroid to a part of the ground electric potential, and suppressing the maximum field strength to promote insulation characteristics. CONSTITUTION:In an impressed impulse voltage, a distance l between the tip of a hemispherical bar electrode 11 and a metal plate 13 of the ground electric potential is varied to derive an impulse flashover electric potential in that case. The ratio between the thickness t of an insulating layer 12 and a gap length is such that the effect to boost a voltage begins to appear from t/l=30 mm/50mm 1/2, the maximum effect is obtained from t/l 1/3, and about 1.5 times of the voltage rise is obtained. The phenomenon is because that the maximum field strength is suppressed by the effect of the insulating layer 12 having a dielectric constant larger than the insulating gas and, at the same time, that the action to suppress the emission of electron from the hemispherical bar electrode 11 works.</p> |
