Circuit board formed with spark gap

摘要

A circuit board formed with a spark gap for protecting a circuit element such as a transistor connected to a picture tube of a television receiver when spark discharge occurring within the picture tube produces a current under a high voltage tending to destroy the transistor. The spark gap comprises a pair of metal balls disposed respectively on the confronting tip portions of a pair of discharge electrodes disposed opposite to each other on an insulator substrate so that spark discharge can always occur across these metal balls without occurring across the electrodes.