The working principle of the ignition coil: When the primary coil is connected to the power supply, a strong magnetic field is generated around it as the current increases, and the iron core stores the magnetic field energy; when the switch device disconnects the primary coil circuit, the magnetic field of the primary coil is rapid Attenuation, the secondary coil will induce a high voltage. The faster the magnetic field of the primary coil disappears, the greater the current when the current is disconnected, and the greater the turns ratio of the two coils, the higher the voltage induced by the secondary coil.
(1) Material: The additional resistance of the ignition coil is made of low-carbon steel wire, nickel-chromium wire, or pure nickel wire.
(2) Features: The resistance value increases as the temperature of the resistor itself increases, and the resistance value decreases as the temperature decreases.
(3) Function: Used to improve the working characteristics of the ignition system, so that when the engine speed is low, the resistance value increases, and when the engine speed is high, the resistance value decreases.
(4) Working process: when the engine speed is low → the contact closure time is long → the primary current increases → the current flowing through the additional resistance increases → the temperature of the additional resistance increases → the resistance value increases → the primary current decreases, which limits the primary current Increase so that the ignition coil will not overheat; when the engine speed increases → closing time decreases → primary current decreases → resistance value decreases → the primary current decreases less, avoiding the phenomenon of misfire at high speed. When starting, because the battery voltage drops a lot, to increase the primary current, the additional resistance is short-circuited to prevent the primary current from falling too much and ensure reliable ignition.
Type of ignition coil
According to the terminals of the low voltage windings, there are two types: two terminals and three terminals;
According to whether there is additional resistance: there are two kinds of additional resistance and no additional resistance;
According to the shape of the iron core, there are two types: open magnetic circuit and closed magnetic circuit;
According to ignition energy, there are two types: ordinary type and high-energy type.
2. Ordinary distributor
Composition: It is composed of a circuit breaker, distributor, capacitor, and ignition advance device. The upper part is the distributor, the middle part is the circuit breaker, and the lower part is the ignition advance device. Usually installed on the left side of the engine, driven by the engine's camshaft or oil pump.