The Collaborative International Dictionary of English v.0.48:
Spark coil \Spark coil\ (Elec.) (a) An induction coil used for producing sparks, esp. in an internal-combustion engine, wireless telegraph apparatus, etc. (b) A self-induction coil used to increase the spark in an electric gas-lighting apparatus. [Webster 1913 Suppl.]WordNet (r) 3.0 (2006):
spark coil n 1: an induction coil used to create sparks