These notes will help you all in your semester as well as in DGCA examinations.
These are refined notes which I had made with lot of efforts and hours of study.
Whomsoever, get through these notes will definitely boosts up to face such examinations.......
Here, I begins......
- Generating system of an aircraft charges the battery is designed for Varying current
- DC armature winding is closed one
- Lap winding works on Low voltage & High current
- Wave winding works on High voltage & Low current
- Coil sides are pole pitch apart ( DC armature) from Full pitch winding
- Commutator in Dc Generator converts Induced AC into DC
- For coil span equal to pole pitch, Black pitch should be equal to commutator bars/poles.
- Wave winding should have at least TWICE around the armature before it closes back.
- Critical resistance of DC generator equal to Field resistance.
- In DC generator, generated EMF is directly proportional to Pole flux.
- Efficiency of shunt generator is maximum when, Variable loss = Constant loss.
- Series field of short shunt DC generator is excited by Load current.
- Shunt generator in a stable parallel operations shows Dropping voltage characteristics.
- Shunt generator in unstable parallel operations shows Rising voltage characteristics.
- Equalizer bars in parallel operations Stabilize operation of 2 over- compounded DC generators.
- 2 parallel shunt generators divide the total load equally in proportion to their KW output ratings only when they have same Rated voltage.
- Under compound shunt generator not use equalizer for stable parallel operations.
- Over-compounded shunt generator use equalizer for stable parallel operation.
- Ohm-meter used to check Continuity and Resistance.
- Reading of Ohm-meter in open-circuit condition--Infinite resistance
- Reading of Ohm-meter in short/continuous condition--Zero.
- In aircraft, protection of batteries should be done against--Internal resistance.
- High frequency & Low current measurements should be done by Thermocouple meter.
- Speed control of DC motor done by- Thyristor
- Power/Voltage transformer is a Constant power device.
- Voltage applied to LCD should be of Low voltage, Low frequency, Out of phase AC and AC with opposite polarity.
- Series generator have Poorest voltage regulation.
- Ideal generator have Zero voltage regulation.
- Compound DC generators are mostly used because Degree of compounding can be adjusted by using a divertor across a series field.
- In DC generator, voltage buildup process is Cumulative.
- Voltage regulator in a circuit is located parallel to the output.
- When a battery is nearly discharged, the voltage reduces with load.
- If aircraft is not bonded correctly, will lead aircraft skin to be corroded.
- Circuit which has the earth going to the aircraft structure is known as Single Pole.
- Static wick discharger, discharges in flight only.
- Screening is used to reduce radio interference.
- Circuit Breaker(CB) is resettable.
- Battery protection unit protects batteries against an internal heat.
- Motor used for engine starting is Series wound.
- Relay is an Electromagnetic Switch.
- Fuses are rated according to Amount of current they carry( in amps.)
- Purpose of a Differential Cut-Out------It ensures that the generator are nearly the same before they come alive.
- A magneto is switched off by Open circuiting the primary circuit.
- An impulse coupling in a magneto is provided to Generate high voltage for starting.
- Loads on aircraft busbar should be in Parallel to reduce current.
- Extinguishant use on magnesium fire----- Sand.
- Extinguishant use on brake fire----- Dry powder.
- Passenger Oxygen drop down mask stowage doors are released-------a) Electrically for chemical oxygen generators. b) Pneumatically for gaseous systems.
- Type of smoke detection system fitted to an aircraft--Optical & Ionisation type.
