Calculation of lightning surges inducing at equipment connecting with 10 Base-5 cable

A lightning surge induction model for local area networks (LANs) that use 10 Base-5 cable has been developed for use in the design of a surge protector for transceivers. The model is shown as an equivalent circuit. Surges induced by lightning were calculated using SPICE based on the equivalent circuit and compared with measurements from a 100-m-long 10 Base-5 cable with a resistive load. The voltage at the transceiver terminal and the current in the protector were calculated using this model, and the calculated values agreed fairly well with the measurements. This demonstrated the usefulness of the method presented for designing surge protectors to be used with LAN equipment.