Encapsulated spark gap - has concentric basin-shaped electrodes with bases separated by heat-resistant mica and sides by insulating glass

摘要

The encapsulated spark gap for shunting overvoltages consists of two concentric electrodes. One is in the shape of a basin or flat open-topped cylinder and the other located centrally within it is either cylindrical or basin-shaped. There may be a peg protruding downwards from the second electrode through an opening in the base of the first one. There is a thin mica sheet between the electrode bases which can withstand temperatures of up to 300 degrees Celsius and the peripheral space between their sides is filled with a glass-type material. This extends around the peg, if present, of the second electrode. ADVANTAGE - Good protection against external moisture.