A Vertex mag, as do all magnetos, produces its own primary current. The mag's coil uses this current in a normal manner to create secondary discharges for the spark plugs.

The special ignition systems with which our young hopeful might become entangled include many two-coil battery ignition distributors as well as a magneto or two. It seems like everyone and his ...

News Published: 04 March 1939 Magneto or Coil Ignition for Motor-Cars Nature 143, 371–372 (1939) Cite this article ...

[Dan] wanted to learn a bit about solid state ignition in engines; to get started he needed a test subject, so he decided he would upgrade his old 12 horsepower lawnmower. Origina ...