| 摘要 |
1,250,441. Capacitors. COQ N.V. 2 Jan., 1970 [20 March, 1969], No. 241/70. Heading H1M. In a high voltage cylindrical capacitor comprising concentrical cylinders 3, 4 at least the facing surfaces of which are conductive and a gaseous dielectric maintained at constant pressure, the ratio between the inner radius R of the outer cylinder and the outer radius r of the inner cylinder is equal to e, the base of natural logarithms, at a given reference temperature, and the gas, its pressure and the main substance of the inner cylinder are selected so that wherein α is the coefficient of thermal expansion of the main substance, k is a constant (the absolute increase of dielectric constant for a one atmosphere increase in pressure of the gas),p is the pressure in atmospheres, T 0 is the reference temperature in Kelvin degrees and T 1 and T 2 are the extremes of temperature to which the capacitor will be exposed in normal use. The variation in capacitance within the temperature range is stated to be below 0À1% and the capacitor may be used as a capacitive voltage divider, e.g. for switch gear. The gas may be air or sulphur hexafluoride. |
