Magneto Ignition System Construction, Working, Applications, Advantages and Limitations
Working of magneto ignition system
Working Magneto ignition similar to the battery ignition system except in the source of energy for operation. The magneto ignition system has its own generator (magneto) to supply necessary energy for the system. There are three types of magnet ignition system- Rotating magnet
- Rotating armature
- Polar inductor type
The figure shows a schematic diagram of a rotating magnet type magneto ignition system. Here a permanent magnet is coupled to the engine by a cam. When the engine runs, the magnet also rotates. With the help of contact breaker, the rotation of magnet causes strong magnetic fluctuations, which induce a high voltage in the secondary coil. The secondary coil is connected to a distributor. The distributor distributes the induced high voltage to the individual spark plug of the engine according to the firing order. The high potential difference between the electrodes of spark plug then cause a spark and then ignite the air-fuel mixture.
🔗Difference between battery ignition system and magneto ignition system
🔗What are the Requirements of an Ignition System?
Applications of magneto ignition
Magneto type ignition finds applications in the engine where other means of electricity not available, such as lawnmowers and chainsaws. Since it self-powered. Operation of magneto offers good reliability. It is also used where other means of electric supply is available, for example, aviation piston engine. The spark intensity of magneto ignition system increase with speed of the engine, so it is used in racing cars.Advantages and disadvantages of magneto ignition
Advantages- It is a self-energizing type ignition system, so there is no need for an external energy source/ heavy battery, and it is compact.
- More reliable as there is no battery.
- It gives good quality spark at high speed.
- Since there no battery, it does not require high maintenance.
Limitations
- Quality of spark at starting is poor.
- The adjustment of spark timing has a significant effect on spark voltage.
- Powerful spark at high engine speed may damage the electrode.