SURGE PROTECTIVE CIRCUIT AND SURGE PROTECTIVE DEVICE

摘要

A surge protective circuit is connected between a single-phase AC power source and an apparatus that operates with electric power supplied from the AC power source to suppress an overvoltage applied from the AC power source to the apparatus. The surge protective circuit includes: a first constant-voltage device and a first discharge device connected in series between a first ground terminal and a non-ground-side terminal of the AC power source; and a second constant-voltage device and a second discharge device connected in series between a second ground terminal and a ground-side terminal of the AC power source. A midpoint between the first constant-voltage device and the first discharge device and a midpoint between the second constant-voltage device and the second discharge device are connected.