Abstract:
An ignition coil assembly is disclosed for a spark plug of the type used in internal combustion engines. The ignition assembly includes a housing, a tubular and cylindrical primary coil, and a tubular and cylindrical secondary coil. The primary and secondary coils are each wound on their individual bobbins and the bobbins are mounted in the housing such that the primary coil is coaxially positioned inside the secondary coil. The ignition coil assembly further includes a magnetic core having a first portion which extends through the interior of both the primary and secondary coil and a second portion which extends exteriorly of the primary and secondary coils. The first portion of the coil is substantially circular in cross sectional shape thus matching the circular interior of the primary bobbin. In order to construct the primary coil and secondary coil subassembly, the primary bobbin is first positioned on a winding machine and the primary wire is wound on the bobbin. Thereafter, the secondary bobbin is positioned over the primary bobbin and the wire for the secondary coil is then wound by the winding machine.