Slant winding electromagnetic coil and ignition coil for internal combustion engine using same

An electromagnetic coil, comprising:

• a winding member having a predetermined length;
• a wire wound around a surface of said winding member, said wire forming a first winding portion and a second winding portion,
• wherein said first winding portion is wound around a first length of said winding member, said first winding portion including a plurality of winding layers overlapped with each other and inclined at a predetermined angle to the first length of said winding member, each of the winding layers including a collection of turns of the wire, and
• said second winding portion is wound around a second length of said winding member, said second winding portion including a plurality of winding layers overlapped with each other and inclined at a predetermined angle to the second length of said winding member continuing from the first length, each of the winding layers including a collection of turns of the wire,
• wherein the winding layers develop a high voltage through electromagnetic induction, and
• wherein the second winding portion includes adjacent winding layers with the number of turns t.sub.H given by the following equation:
• t.sub.H .ltoreq.n.sub.T /V.sub.OUT .times.180
• where n.sub.T is a total number of turns of said first and second winding portions, and V.sub.OUT is an output voltage of the electromagnetic coil.