Final Flashcards
Ohm’s Law
The flow of current through a conductor is directly proportional to the voltage and inversely proportional to the resistance.
Conventional Flow VS. Electron Flow
Conventional flows positive to negative, Electron negative to positive.
Electromotive Forceel
The force that causes electrons to move in an electrical circuit.
Kirchhoff’s voltage law
The sum of the voltage drops around any loop of a circuit is equal to the voltage source. Parallel circuits.
Kirchhoff’s Current Law
The current leaving any point is equal to the current arriving at that point, which means current is the same anywhere in a series circuit.
Impedance in a AC circuit
Resistance, inductive reactance, capacitive reactance
Thermocouple
A device consisting of two different conductors that produce a voltage.
AC Power Generation
Relative motion between a wire and a magnetic field generates an EMF and a flow of current in a closed circuit.
Transformers
Voltage is proportional to number of turns and current is inversely proportional.
Output of power generations is determined by?
Strength of the magnetic field, number of conductors, and the speed that the magnetic field is crossed.
Pulsating DC
DC whose voltage periodically changes, but whose electrons always flow in the same direction.
What is a commutator?
A mechanical rectifier mound on the armature of a DC generator.
Pro’s of using AC generators
Produce high voltage so less current can be sued, smaller wires, easily transformed, simpler and more reliable.
Series wound
not practical because they can’t be controlled
Compound wound generate
They are normally starter-generators
Residual magnetism
The magnetism that remains in the field frame of a generator when no current is flowing in the field coils
Residual Voltage
The voltage produced in a generator armature when the armature when the armature is rotated in the residual magnetism.
Voltage Regulator
A normally closed switch that is opened whenever there is a voltage greater than desired in a parallel circuit. This limits current going to the magnetic field.
Current Limiter
A normally closed switch that is opened whenever there is current greater than desired in a series circuit. Limits current going to the magnetic field
Reverse current relay
A normally open switch which is held closed by a magnetic coil whenever there is sufficient output from the generator going through a parallel and a series circuit
Why do aircraft use single wire systems?
Circuits are completed through the ground.
What is a shunt?
A conductor with a known resistance
What had to be done on parallel buy systems?
Generators synced for phase a frequency
Ground waves
Travels close to gorun
VLF and MF waves
Sky waves
Bounce of Ionosphere
HF waves
Transcontinental
Space waves
Line of sight
VHF to EHF
Talk to tower,ground, or other aircraft
