Very similar to an electric transformer, ignition coils have both primary and secondary winding circuits.
Even though they are used in larger, multi-part ignition systems, ignition coils can be considered the most essential component of the system. It would be ineffectual without both the high voltage and ignition energy provided by these specific electric coils. The most common application of ignition coils is in the automotive industry, in which they are used for vehicle ignition systems such as in cars, minivans, trucks, SUVs, motorcycles and more.
Another common automotive coil is the choke coil, which is usually a part of an engine. However, ignition coils are also utilized in additional industries such as: industrial manufacturing, for material handling equipment such as forklift trucks and mobile overhead cranes; agriculture, for farming equipment such as tractors, combines and balers; and recreation, for off-road vehicles such as quads, dirt bikes, three-wheelers and golf carts.
Ignition coils must not only be manufactured from conductive materials such as copper or silver, but must also be formed from materials offering high-temperature resistance.
The ignition coil functions to fire up the spark plugs by means transforming the current flow from the vehicle’s battery (typically a twelve volt or a six volt) into the many thousand of volts (between twenty and thirty thousand volts) required by the spark plugs. An ignition coil is similar to other types of electric coils in that it consists of a core and two wound wires, a primary and a secondary.
The primary coil is commonly manufactured from a very heavy gage of copper that is insulated in protective materials that disable the current flow from jumping from one loop to another and consequently shorting out the system. The primary coil generally contains about one hundred to one hundred and fifty turns, or coils of wire.
The secondary coil, on the other hand, is typically manufactured from a very fine gage of copper, which must also be insulated to protect against shorting the system. The secondary coil contains many more turns than the primary coil, generally ranging from fifteen thousand to thirty thousand. The secondary coil is fitted inside the turns of the primary coil and both coils are wrapped around the core.
Typically cylindrically-shaped, the core of an ignition coil is manufactured from soft iron that is filled with oil that serves as a coolant enabling the core to withstand the extreme temperatures reached by the current flow.