Design of multiple stage avionics lightning protection for DC power input lines using a graphical user interface (GUI)

All interfaces to electronic equipment on aircraft (avionics) are required to tolerate the indirect effects of lightning transients. Designing protection against high levels of lightning transients for DC power input lines presents a unique challenge in that gas discharge tubes (GDT) may function in an undesired manner when installed on power lines. An alternate solution to GDTs is to cascade multiple protection circuits. This paper presents an example design. In addition, a GUI developed to facilitate the design of lightning protection circuits is introduced and used for the example design.