What is the working principle of an engine ignition coil?
1 Answers
The ignition coil is essentially a transformer that operates on the principle of electromagnetic induction. It converts the 6-volt low-voltage current from the battery or magneto into a high-voltage current ranging from 11,000 to 15,000 volts. The ignition coil primarily consists of a low-voltage coil (also known as the primary coil), a high-voltage coil (also known as the secondary coil), and an iron core. The low-voltage coil is wound with thicker copper enameled wire and has fewer turns. One end of this coil is connected to the power source, while the other end is linked to the circuit switch (breaker). The high-voltage coil, on the other hand, is wound with finer copper enameled wire and has many more turns. One end of this coil is connected to the spark plug, and the other end is grounded to the vehicle body. Below is a brief introduction to the ignition coil: 1. Function: It transforms low-voltage direct current into high-voltage electricity, which can reach tens of thousands of volts, and uses the spark plug in the cylinder to ionize and break down the air, generating an electric spark. 2. Transformer: Ordinary transformers operate at a fixed frequency of 50Hz, also known as power frequency transformers. In contrast, the ignition coil operates in a pulsed manner and can be considered a pulse transformer. It repeatedly stores and releases energy at varying frequencies depending on the engine's speed. When the primary coil is connected to the power source, a strong magnetic field is generated around it as the current increases, and the iron core stores this magnetic field energy.