Overvoltage protection circuit for protecting signal line from overvoltage during lightning strike, has set of overvoltage arresters connected to another arrester set, which provides current when voltage exceeds threshold value

摘要

The circuit has two overvoltage arresters (4, 5) i.e. gas arresters, actuated, when voltage at signal lines (1, 2) exceeds a threshold value to discharge voltage as short circuit current to an earth potential (3). A display device (8) is supplied with electrical energy and changes a display condition during actuation. The arresters (4, 5) provided in the display device are connected to overvoltage arresters (6, 7) i.e. gas arresters, in parallel. The arresters (6, 7) provide a supply current for the display device, when the voltage on the lines exceeds another threshold value.