S 320 LWB (140.033) L6-3.2L (104.994) (1995)
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Ignition Coil: Description and Operation
Ignition Coil
The ignition coils (T1) have two high-voltage connections (4a, 4b). Each connection supplies one spark plug with high-voltage.
The engine control module limits the primary current to approximately 7 A. The maximum ignition voltage is approximately 32 kV.
WARNING: The primary connections deliver voltage up to 400 v. Guide sleeve (w) must always be connected to vehicle ground.
Design and Function
Ignition Coil, Cross Section View
The ignition coil is constructed much like a transformer, where the primary and secondary windings are physically separated from one another.
Both ends of the secondary winding are equipped with a high-voltage connection which form, together with two spark plugs, a closed circuit. The
secondary winding produces high-voltage during ignition.
The ignition spark occurs at both spark plugs at the same time, whereby one spark jumps from the center to the ground electrode and the other
from the ground to the center electrode. As a result, constant positive and negative high-voltage to ground is present at the secondary connections.
The ignition spark on the exhaust stroke requires very little energy, so that nearly all the energy stored in the coil is available for the power stroke.
