A small device installed inside gate controller or separate housings in between your incoming power and the gate controller power connection, this fully protects your device from any power surges.
W.A. especially has constant power surge issues which cause lots of damage to sensitive electronic devices, also during the winter storms, where power poles are exposed to lightning strikes.
These devices will give constant protection from surges, and will self-sacrifice in the event of a direct lightning strike to power poles from in coming power.