This invention relates to a
relay and an automatic
circuit protection method using the
relay. The
relay includes a housing, conductive steps disposed on the inner walls of the left and right sides of the housing, and a stepped conductive bridge that can dynamically fit with the conductive steps. External cables pass through the housing and are electrically connected to the conductive steps. A
piston push rod device drives the conductive bridge to rise and fall, connecting or disconnecting it from the conductive steps. The
piston push rod device is driven by vapor generated by the sublimation of an easily sublimable substance. This relay and the automatic high-
voltage circuit protection method using the relay are not only reusable, but also have a simple and stable structure, low manufacturing and
assembly costs, stable operation, long service life, and can reliably achieve power
cut-off in a fire.