Starlike functions associated with some hyperbola

An ignition system for an internal combustion engine including a multi-breaker point distributor in which the respective sets of points are arranged at mutually offset and overlapping dwell angles. Electric circuitry is provided to selectively connect and disconnect the various sets of points to vary the total length of dwell and thus the ignition timing. A commutator can be used to alternately connect and disconnect the various sets of points, thereby continuously and relatively advancing and retarding the ignition timing between predetermined limits from a variable zero position. A sensing device can be employed to sense variations in an engine operating condition and relatively advance or retard the zero position of the ignition timing to maintain a predetermined value of the operating condition.