Ignition coil for internal combustion engine

摘要

An ignition coil for an internal combustion engine to suppress the superposition of a noise signal caused by a capacitive discharge current at an ignition plug to thereby prevent the faulty operation of other circuit devices. The ignition coil has first and second non-magnetic bobbins into which a magnetic core 3 is inserted, a primary coil (1) wire wound around the first bobbin, a secondary coil (2) wire wound around the second bobbin, an interrupting circuit 7 connected to one end of the primary coil for interrupting a primary current i1 flowing to the primary coil, and an ignition plug 5 connected to one end of the secondary coil for generating a discharge spark by a secondary voltage V2 output from the secondary coil. A buffer coil 8 having an inductance which is much smaller than that of the primary or secondary coil is connected in series with one of them.