Ignition coils are considered pulse transformers and perform all of the following except which?

• A. Deliver the spark to the plug as timed by the ignition system
• B. Step up voltage to high voltage
• C. Store energy in magnetic field
• D. Change low amperage to high amperage

Answer: (D)

Ignition coils act as pulse transformers that store energy in a magnetic field while the primary winding is energized, then release that energy as a very high voltage in the secondary winding when the current is interrupted. This high voltage is what creates the spark at the plug, timed by the ignition system to fire at the right moment. Because a transformer increases voltage by exchanging current, the secondary current is not higher than the primary; in fact, the current on the high-voltage side is much lower while voltage is much higher. So the coil does not convert low amperage into high amperage; that is the aspect that doesn’t fit.