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Ignition Coils

The ignition coil as component of the inductive ignition system transforms the low battery voltage (12 V) to the 45 kV needed to create an electric spark in the spark plugs. Ignition coils operate according to the principle of an induction coil. Every time the primary current of the coil is turned off by a transistor, a self-inductance voltage is produced at the primary winding and then a high voltage pulse is transformed in the secondary winding. This high voltage is transferred to the spark plug gaps of the spark plugs via the ignition cables. The fuel-air-mixture is then ignited by this spark in the cylinder of the spark ignited internal combustion engine.

BBT offers ignition coil rails, block ignition coils, pencil coils and plug top coils for German, European and Asian cars in OEM and Aftermarket version. All our ignition coils are tested technically in our own facilities according to high quality requirements before they are sold.

BBT produces different types of ignition coils at our production site since 2009. With over 25 years of experience in the field of ignition technology, BBT has enough expertise in order to supply the spare part marked with self-developed products.


Construction of an ignition coil

The ignition coils consists of an iron core with isolated thin steel sheets on which the primary and secondary bobbins are fixed. The function of the iron core is to create a magnet field within the ignition coil and to store the created energy. The stored energy is discharged as soon as the primary circuit is broken off. This happens at a defined ignition time.

The primary coil is surrounded by an enamelled copper wire which is significantly thicker (about 0.7 mm² in diameter) than that one of a secondary coil. Hence, the primary coil has less windings than the secondary coil.

The enamelled copper wire of the secondary coil is finer in its structure (from about 0.05 mm² in diameter) than that one of the primary coil. The number of windings is notably higher in proportion to the primary coil due to thickness of the wire.

The generated high voltage is isolated by a two-component epoxy resin. The potting of the epoxy resin in the ignition coil production is made under vacuum to ensure the perfect insulation and high voltage resistance.

The ignition voltage of the bloc coil is conducted to the spark plugs by means of ignition wires. The ignition coil rails, pencil coils and plug top coils, however, are directly placed on the spark plugs.

BBT ignition coil View of the interior of BBT ignition coil