Definition
A multi-position electrical switch designed so that the moving contact touches the next position before it leaves the previous one. This ensures the circuit is never momentarily open during switching.
Plain English
A switch that connects to the new contact first, and only then lets go of the old one — so the circuit is never even briefly broken while you change positions.
Context Anchor
Seen in aircraft electrical systems, avionics selector switches, and equipment circuits where a steady connection is important during switching.
Derivation
The name describes the action literally: the switch makes (connects) the new contact before it breaks (disconnects) the old one. The opposite type is called a break-before-make switch, where the old contact is released first, briefly leaving the circuit open.
Why Pilots Care
Prevents avionics resets, instrument glitches, or loss of navigation during power transfers in flight.
Analogy
It is like stepping onto the next rung of a ladder before lifting your foot off the previous rung. There is a short moment when you are supported by both.
Intuition Check
“Make” does not mean manufacture here; it means close an electrical path. “Break” does not mean damage here; it means open an electrical path.
Example Sentence 1
The autopilot mode selector uses a make-before-break switch so the system doesn't drop offline when the pilot changes modes.
Example Sentence 2
Maintenance confirmed the make-before-break switch on the essential bus was functioning to avoid any interruption when swapping between generators.