Definition
An electrical switch designed so that its contacts open and close rapidly, regardless of how slowly the operator moves the switch lever. An internal spring stores energy as the lever is moved and then releases it suddenly, snapping the contacts apart (or together) at high speed. This minimizes arcing and contact erosion when switching circuits that carry significant current.
Plain English
A switch with an internal spring that makes the contacts snap open or shut quickly, even if you flip the lever slowly. The fast snap reduces sparking and protects the contacts from burning.
Context Anchor
Seen in aircraft electrical system discussions, especially where switches must open a circuit cleanly and reliably.
Derivation
Named for what it does: the contacts 'break' (open) 'quickly,' independent of the operator's hand speed. The mechanical trick is that the spring, not the operator, drives the final motion of the contacts.
Why Pilots Care
Rapid action prevents electrical arcing that could start fires or damage sensitive avionics during flight.
Analogy
It is like a household light switch that snaps from on to off instead of slowly sliding through the middle; the quick snap helps make a clean change.
Intuition Check
Do not read “break” as “damage.” In this term, “break” means “open the electrical path so current stops flowing.”
Example Sentence 1
The magneto switch is a quick-break switch, so even a hesitant flip of the key still opens the primary circuit cleanly.
Example Sentence 2
Maintenance replaced the aging quick-break switch to stop intermittent arcing in the battery bus.