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Electronic ignition system


Electronic ignition system

1. controller

2. electromagnetic valve EPHH

3. screw sensor

4. coolant temperature sensor

5, 6. inductive reference and angular pulse sensors

7. ignition coils

8. spark plugs

9. ignition switch

10. battery

11. fuse and relay block


In the electronic ignition system, which is one of the most important components of a modern car, high voltage current is created and distributed thanks to electronic devices. The electronic system has many clear advantages and also makes it easier to start the engine in winter.

An electronic ignition system is a system in which high voltage current is generated and distributed by electronic devices. The electronic ignition system of modern cars, which controls the injection and ignition systems, is an important component of the engine management system. On cars of the latest models, the same system is responsible for the operation of the intake and exhaust systems, as well as the operation of the cooling system.

Today, the market offers such ignition systems as Bosch, Simos, Motronic, Magneti-Marelli, each of which is structurally different from the others. In general, we can say that electronic ignition systems are divided into direct ignition systems and distributor systems. The latter operate from a mechanical distributor , which supplies high voltage current to a specific spark plug. If we are talking about direct ignition systems, then the current is supplied to them directly from the ignition coil.

Electronic ignition system device

Any electronic ignition system includes components such as a power supply, input sensors and ignition switch , electronic control unit, igniter, coil and spark plugs . Some systems also have high voltage wires .

Input sensors are responsible for recording the current engine operating parameters, converting them into electrical signals. The range of sensors may vary slightly depending on the car model.

The electronic control unit processes the signals coming from the input sensors, influencing, in turn, the igniter. The igniter, which is based on a transistor, is a kind of electronic board that turns the ignition on/off. When the transistor is open, current flows through the primary winding of the coil. If the transistor is closed, it is cut off, and the current is induced through the secondary winding of the coil.

The electronic ignition system can have different coils: one common, individual or dual. Common coils are used in systems that have a distributor. Individual coils are installed directly on the spark plug, so high-voltage wires are not used in such a system.

Twin coils are used in direct ignition systems. If the engine has four cylinders, one coil is installed on the 1st and 4th, as well as on the 2nd and 3rd cylinders, each of which is responsible for creating current at two terminals, which is why ignition sparks appear simultaneously in two cylinders In one, the fuel-air mixture ignites, in the other, ignition occurs idle.

Principle of operation

The electronic control unit responds to sensor signals, calculating the optimal parameters for the operation of the system. First of all, the control unit acts on the igniter, which supplies voltage to the ignition coil , in the primary winding of which current begins to flow.

When the voltage is interrupted, a current is induced in the secondary winding of the coil. Directly from the coil or through high-voltage wires, the current is sent to a specific spark plug, in which a spark is formed that ignites the fuel-air mixture.

If the speed of rotation of the crankshaft changes, the sensor responsible for its rotation frequency, as well as the sensor that regulates the position of the camshaft, send signals directly to the electronic control unit, which changes the ignition timing.

If the engine load increases, the ignition timing is controlled by an air flow sensor . The knock sensor provides important additional information about the ignition and combustion of the fuel-air mixture.

Advantages of electronic ignition systems

Electronic ignition systems have many advantages:

  • possibility of use on any type of carburetor engines.
  • increase in secondary voltage by 1.3-1.5 times, which can be 20-30 kV in any engine operating mode.
  • long service life of the breaker contacts, which can reach 150 thousand km or more.
  • an increased gap is observed between the electrodes of the spark plugs , reaching 1-1.2 mm.
  • in winter, the engine starts easier.
  • saving time when carrying out preventive and adjustment work.

Among the disadvantages of electronic ignition systems, the complexity and high cost of the system primarily stand out, but all the disadvantages are compensated by the above advantages.



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