Generators Flashcards
The generator left-hand rule
(T)humb- direction the conductor
(I)ndex - direction of the (f)lux lines
(M)iddle- direction of induced EMF
Two instrument used to measure current
- Ammeter
2. Galvanometer
The component which converts the AC output of a simple AC generator into DC out (Not an invertor)
Commutator
The method of how a commutator maintains DC output in a basic DC generator
At any given point, the brushes only make contact with 1 side of the commutator
Although the current reverses direction in DC generator, the ________ causes current to flow in only one direction
commutator
The 4 main parts of a DC generator
- Field frame (yoke)
- Commutator
- Brushes
- Armature
The type of armature typically used in a DC generator
Drum-type
The two major components of the DC generator armature
- Iron core
2. winding
The two functions of the DC commutator split ring
- Collecting the current from the armature
2. Converting the AC current from the armature into DC output
Two typical construction materials of DC generator brushes
- carbon
2. graphite
The function of the carbon/ graphite brushes in a DC generator
To collect current from the moving commutator
The means at which the external circuit is connected to the carbon brushes
Pigtails
The 3 types of DC generators
- Series-wound
- Shunt-wound
- Compound
The DC generator with the poorest voltage regulation capabilities
Series wound
The relationship between voltage and current in a series wound DC generator
The current through the field coils increases as the load voltage increases
Typical DC generator rating
300 amps, 28 V
The function of a current limiter in a DC Generator
Limiting of the generator output current in a DC generator
The function of the Reverse-current cutout in a DC generator
The disconnection of the battery from the generator when the generator output is lower than the battery output
The reason why the reverse current cutout disconnects the battery from the generator during low generator output
If the generator output is lower than the battery output, the battery would discharge itself through the generator armature
The term for When the battery attempts to discharge itself through the generator armature and attempts to drive the generator as a motor
Motoring
The type of damage mostly found on contacts of any type
Pitting
In a DC generator, the component that is in between the carbon brushes and the external circuit
The pigtails
Brushes are held in place against the commutator via
Spring loaded brushes
When the spring tension on a DC generator is poor, the most probable damage that will occur
DC generator Arcing occurs when
