Unit 1-9 Flashcards
What are series circuits?*
What is constant in this circuit?*
One current path
All electrons (current) travel through all components of the circuit
Current is constant
What are parallel circuits?*
What is constant in this circuit?*
More than one current path
The flow of electron is divided into different paths
Current can be different for different portions of the circuit
Voltage is constant
What are series/parallel circuits?*
A combination of both series circuitry and parallel circuitry
What is polarity?
The location of the positive connection compared to the negative connection
Describe direct current
Where is DC power used?*
Is polarity constant?*
Electrons flow in one direction
Current from batteries
Can be constant or pulsating
Portable/movable (satellites, airplanes, UAVs,
spacecraft) systems use DC
The polarity of the voltage is constant
Describe AC current
Where is AC power used?*
Is polarity constant?*
The current flows in one direction, reverses, and flows in the other direction
AC is the current of houses, large aircraft
The voltage constantly changes
The polarity reverses once every cycle
What is the frequency of AC voltage?
The speed at which the polarity reverses
Must be a constant for any given systems
Measured in Hertz (Hz) or Cycles per second (CPS)
What is rectification?*
Circuits to change AC to DC
Use rectifiers
Typically employ diodes
Full wave – most efficient
What is inversion?*
Circuits to change DC to AC
Use inverters
Complex
Low efficiency (heat produced as a waste produce)
What are advantages of DC power?*
Batteries can store DC
Batteries in most portable items
Used for A/C backup power
Used to start the engine
What are advantages of AC power?*
Easily converted to different voltage levels through transformers
Higher voltage is “easier” to transmit through wires Higher voltages, lower amperages
Brushless motors
Three phase systems (more power)
