Ignition coils

IGNITION COILS

The ignition circuit is the inductive discharge, static advance type, where the high tension is supplied by four coils fitted directly on the spark plugs (pencil-coils).

The coil used is the closed magnetic circuit type, with the windings in a plastic container, immersed in epoxide resin. The coil is connected directly to the spark plug by means of an extension made from silicon which has good dielectric properties.

The coil incorporates a power transistor for interrupting the primary winding.

The primary winding in eah coil is supplied by the battery voltagte (+30) via the twin relay and is connected to earth through the built in power transistor with the base connected to the appropriate control unit pin.

Interrupting the current to the base of the transistor interrupts the connection to earth of the primary winding and, as a result, causes a high tension discharge at the secondary winding.

The optimum ignition advance is calculated by the control unit according to the engine speed and load conditions and is implemented in the form of time between the TDC for the explosion stroke and the moment the supply for the coil primary circuit is interrupted.

Wiring connector

1. Cylinder 1 coil
2. Cylinder 2 coil
3. Cylinder 3 coil
4. Cylinder 4 coil
5. Interface connector
6. Engine earth