Electromagnetically actuated, fast-closing switch using polythene as the main dielectric

A switch consisting of two electrodes separated by a polythene sheet and which is closed by driving a rivet through the dielectric, so as to firmly join the electrodes, has operated in 40kV circuits with peak currents up to 600kA and passing a total charge of 2500 coulombs. The switch closes in about 50¿s with shot-to-shot variations of ± 1 ¿s. The metal-to-metal contact has a d.c. resistance of about 1 ¿ ¿. The rivet is driven by a hammer repelled from a fixed coil which is pulse-energised from an auxiliary capacitor