breakdown voltage (electrical component rating). The voltage that must be placed across the dielectric in an electrical or electronic component to cause the dielectric to break down and conduct current.
breaker-point bounce. A condition in which the breaker points in an aircraft magneto bounce open, rather than remaining closed when the cam follower moves off of the cam lobe. Breaker-point bounce is caused by a weak breaker-point spring.
breaker points (magneto component). Electrical contacts in the primary circuit of an aircraft magneto that are opened by a cam turned by the engine. The breaker points are timed to open at the instant the ignition spark should occur. When the points open, the primary current stops flowing, and its magnetic field collapses.
The lines of flux from the collapsing primary magnetic field cut across the many turns of the secondary winding and induce a high voltage in the secondary circuit. It is this high secondary voltage that causes a spark to jump across the gap in the spark plug.