Ignition & Starting Systems Flashcards
- What is a magneto?
Self contain AC generator that provides ignition to the engine
- Why are magneto ignition systems preferred over battery type ignition systems for reciprocating engine?
Magnetos are independent ignition source & do not rely on battery power
- What can cause a reciprocating engine to continue to run when ignition is in the off position?
P-lead break needs ground to shut off
- What is the purpose of the condenser in a high tension magneto electrical system?
Prevent arcing at the points & hasten magnetic field around primary coil
- Where is the e gap position?
Poles of rotating magnet are few degrees past neutral
Points start to open
- What are the three major circuits of a high tension magneto system?
Magnetic
Primary
Secondary
- What are the components of a high tension magnetic circuit?
Permanent rotation magnet
Soft iron core
Pole shoes
- What happens when the primary breaker points open in a magneto?
Stops flow of current in primary coil
Magnetic field collapses creating induce pulse of high voltage current creating spark
- What is the position position when the spark occurs in a cylinder?
Specified # of degrees before TDC
- What is a dual magneto?
Two magnetos in one housing
- What is the difference between a low tension and a high tension ignition system?
High tension - high voltage from magneto to plugs
Low voltage - low voltage from magneto to transformer coil near plug then increased to high
- When the ignition switch is OFF position, what is the condition of the primary circuit?
Completed through ignition switch to ground
- What three conditions are required to fire plugs in a cylinder when the piston is in the prescribed position?
E gap
Breaker points open
Distributor rotor aligned with electrode
- What is a dual ignition system, and what part of the system is grounded when the ignition switch is placed in the RIGHT position?
The left magneto is grounded meaning OFF
- What is internal timing of a magneto?
Adjusting the breaker points to open with poles of magnet
- What is the purpose of an impulse coupling used with a magneto?
Retard the timing of the spark till after TDC for starting
- What is staggered ignition timing?
Fires one spark plug before the other vs all at same time
- What is the proper spark plug reach?
When electrode end of the plug inside the cylinder is in the best opposition for ignition
- Why is it important to keep track of the cylinders that spark plug are installed in?
Spark plugs provide health information about that cylinder
- What type ignition system is used in most turbine engines?
Electronic capacitor type ignition system
- What is the function of the igniter plugs in a turbine engine?
Provide discharge gap for current
- When are turbine engine ignition system normally used?
For starting or restarting
- What are two types of igniters plugs?
Annular gap
Constrained gap
- What is the purpose of the dual magneto configuration?
Redundancy
- How can you tell if a starter commutator is dirty or worn?
Excessively noisy starter
- What does it mean when the starter relay clicks when the starter switch is placed in the START position?
Supply voltage too low
- What is an advantage of air turbine starters, when compared to electric starter, for large turbine engines?
Light weight
- Why do turbine igniters not get carbon fouled as often as reciprocating singe spark plugs?
Due to High rates of electrical discharge
- What are the three parts of an ignition system of a turbine?
Exciter
Ignition lead
Igniter
- What is the difference between a temporary magnet and a permanent magnet?
Permanent retains its magnetic properties
Temporary acts as permanent when within magnetic field of permanent magnet
