The Light Power Distribution board (LPD) is designed for installations where power and signal are provided in the fuselage and linked via servo wire to the wing tips and other locations. The long wire runs can pose signal risks to an RX if connected directly to a serial bus output. Also, risks of tip damage through flight or from pyro heat which can results in shorts, and potentially complete light failure can be isolated to a single tip allowing the display to continue or a safe landing to made.
The switch is a 'standard' soft switch circuit, although no switch is provided and the user is free to selected their preferred switch type (pin, slide, toggle etc). Shorting the outer two pins on the switch connection will turn the power off. The switch circuit will withstand high transient surge currents.
The RX signal is buffered and soft protected against short to ground or 12v. The RX input is isolated from the lighting wiring.