"Mind the gap” is an expression that’s frequently heard on the London Underground. It also applies to manufacturers that build products equipped with battery chargers, converters, inverters, regulators, transformers, transistors and other types of power electronics.
In England, “mind the gap” is a polite way to warn people to be careful when entering and exiting trains. In the manufacturing world, it means engineers should pay attention to wide bandgap (WBG) semiconductors.