The voltage in this winding is much higher than that in the primary winding. This is because there are more turns of wire in the secondary winding for the field to act on. The way the current supplied to the primary winding is interrupted depends on the type of coil. In induction coils used to fire the spark plugs in some automobile engines, for example, the primary current is interrupted by mechanical breaker points that are opened and closed by the car's distributor. In induction coils used to ignite gas stoves, jet engines, and oil burners, the primary current is broken by a magnetic vibrator similar to the type used in doorbells.
Some induction coils use a transistorized electronic circuit to interrupt the primary current.
How to cite this article.