Unit 1-4 Flashcards
What is the function of a transformer?*
What two kinds of windings (coils) does it consist of?
Increase or decrease voltage in an AC (alternating current) circuit using electromagnetic induction
Primary (high voltage)
Secondary (low voltage)
How does magnetic flux move from winding to winding in a transformer?*
The flux from the primary winding goes to the secondary winding via the transformer core, this can either drop or raise the voltage
What is a relay?
How do they work?*
A control device & a power consumer
An electrically operated switch
Current flowing through a coil creates a magnetic field and attracts a lever
Describe the schematic symbol for relay
A coil, a line, then the switch (SPDT, DPDT, etc.)
What are advantages of relays?*
Disadvantages?*
Advantages:
Can switch AC and DC
Can switch higher voltages
A better choice for switching large currents
Can switch many contacts at once
Disadvantages:
Big & heavy
Slow
Use more power due to the current flowing through coil
What is a solenoid?
What type of functions does it perform?*
What would it be used for?
An electromagnet with a movable core
A simple coil used to create an electromagnet & to create movement
Mechanical functions
High current & mechanical devices
Door latch
School bell
How is a solenoid different from a relay?*
Relay uses an electromagnet with a fixed iron core
Solenoid uses an electromagnet with a moveable core
A solenoid is much stronger than a relay
What does Moore’s law state?
The number of transistors on integrated circuits doubles approximately every two years.
What is a wire?*
What is a cable?*
A single conductor which may have an outer layer of insulation
An assembly of two or more conductors separated, insulated, and grouped together
Know the difference*
Describe a single core wire
What types of connections is it used for?*
One solid wire with a plastic coating available in a wide variety of colors
Can be bent to shape, but breaks if repeatedly flexed
Used for connections which will not be disturbed
Example: links between points of a circuit board
Describe a stranded wire
What types of connections is it used for?*
Many fine strands of wire covered by an outer “plastic” coating
Flexible - can withstand repeated bending
Used for most aircraft wiring
Aircraft can grow 2-3 inches in flight
Which Advisory Circular specifies approved wires for aircraft?
Is this approved data? Why or why not?
AC 43.13-1B
Not approved data, only manufacturer data is approved and the AC is from the FAA
What are terminal strips?*
Semi-permanent wire setting
Set of screws hold down the wires, simply loosen the screw to remove the wire
What are some types of connectors?*
Molex
AMP CPC
BNC
What are LRUs?
Where can they be found?
When would this be helpful?
Line Replaceable Units
Possible to quickly disconnect and reconnect the LRUs to the aircraft using connectors
Voltage regulators, flight management computers, inverters, and radio equipment
You have a bad radio, maintenance can disconnect it and connect a new one in little to no time
