Overvoltage transient protection network design

Transient over-voltages caused by lightning, couples on to data communication or instrumentation signal lines and introduce serious fault alarm conditions and damage instrumentation electronics. Protection circuits to minimise the transient over-voltage are commercially available for variety of installation requirements. However, if an electronic system designer intend to build a protection circuit, a custom design will be desirable as the interface or inter-connection could be more effective for the intended environment. This paper brings out the various designs approach for a number of applications from radio communication antennas port to data acquisition signal lines. Also, the design details for a hybrid protection circuit is provided along with the results achieved.