When the ignition switch is turned to the start position or returns to the ignition position after starting, the ignition circuit operates by supplying power to the battery (+), ignition switch contact 30, and the ignition controller and Hall pulse generator via the first circuit; the second circuit supplies power to the primary winding of the ignition coil, the ignition controller, and the battery (-). The iron core in the ignition coil generates a magnetic field under the influence of this current. When the distributor rotor interacts with the Hall element, the ignition controller disconnects the operating current in the primary winding of the ignition coil. The magnetic field in the iron core of the ignition coil quickly disappears. The secondary winding of the ignition coil then generates high voltage, which is distributed to the spark plugs of each cylinder according to the engine's firing order via the distributor rotor. This breaks down the gap between the center electrode and the side electrode of the spark plug, generating a spark that ignites the combustible mixture.
Power supply circuit working principle
The automotive power system includes two power supplies: a battery and an alternator. The alternator's operating circuit is as follows: When the ignition switch is in the ignition position, the alternator's magnetic field circuit operates via the battery (+) terminal, ignition switch contacts 30 and 15, alternator fault indicator light 1, alternator magnetic field winding 1, voltage regulator, and battery (-). A magnetic field is generated in the alternator's rotor core, which, driven by the engine crankshaft pulley, generates a voltage in the three-phase windings of the alternator stator. In the circuit design, the alternator output terminal is connected to the battery electrode (+).
When the generator is working normally, the two sides of the generator fault indicator light are at the same potential, so the fault indicator light does not light up; however, when the generator malfunctions and cannot work normally, the operating current in the fault indicator light circuit flows in the same direction as the magnetic field excitation current when the generator starts working. At this time, the fault indicator light will light up.
Instrumentation Circuit
The instrumentation circuit consists of an ammeter, an oil pressure gauge and oil pressure sensor, a low oil pressure gauge and sensor, and a water pressure gauge and sensor. Its function is to monitor and indicate the operating conditions of each system. Except for the ammeter, all other instruments are connected in parallel, but each instrument and its sensor are also connected in series, thus maintaining the independence of each instrument's operation. The circuit diagram also includes a low oil pressure warning light and its sensor. The inclusion of warning devices in the instrumentation circuit reflects a trend in the development of electrical equipment.
Lighting and signal system control circuit
The lighting and signaling system, commonly known as the lamp system, includes all electrical components of the vehicle's lighting and signaling systems, switches, fuses, etc. The main lighting switch is the central control point for the lighting equipment. In addition to bimetallic fuses protecting the lighting circuits, each individual lamp circuit is also protected by fuses.
