Unit 1-8 Flashcards
What does the regulator do?*
Control the input (field) current and change gen/alt output (voltage/current)
Determines the strength of the output of the coil
How would you identify a generator from a picture?
Alternator?
Magnets on the outside, armature (coil) on the inside is generator
Magnets on the inside, armature (coil) on the outside with three outlets for current is alternator
What are the inputs of a regulator?*
Outputs?
Inputs:
Mechanical energy
Engine driven/RPM, APU driven, RAT (ram air turbine) driven
Electrical energy
Field current, main bus (electrical distribution bar)
Output
Voltage/current from armature – to power systems
What are the two basic types of alternator regulators?
Mechanical (vibrating)
Solid State
What parts make up a three-unit regulator?*
Reverse current relay (RCR)
Current limiter
Voltage regulator
Why were vibrating regulators replaced with transistorized regulators?
Cheaper (no coils)
Better
Lighter
More reliable (no mechanical movement/vibration)
Longer MTBF (mean time between failures)
Describe a mechanical (vibrating) regulator
What is their function?
Vibrating points that close electrical contacts
Moving connections (old school)
Basically relays with contact points
Control input to control output
Control field current – controls armature output
More Field – more alternator output
Describe a solid state (transistor) regulator
What is their function?
No moving parts
Transistor replaces the relay (vibrating regulator) to control field current
Smaller input, larger output
No moving connections
Control input to control output
Control field current – controls armature output
More Field – more alternator output
What is a Zener diode?*
Most solid state voltage control units
Voltage sensitive diode
Controls the transistors
Looks like a diode with a “Z” instead of a line
What is a loadmeter?*
What does it do?*
What does a higher number mean?
Scale beginning with zero
Used in light aircraft
Shows the load being placed on the alternator/generator
Measure alternator output current in amps
More things running (radio, charger), higher number
Want it as low as possible
What is an ammeter?*
What does it do?*
What does a positive/negative number mean?
Scale is from negative to positive with zero in the center
Monitors the performance of the electrical system
Want the number to be higher than zero or at 0
Positive = the charging rate of the battery
Negative = more current being drawn from battery
What is a voltmeter?*
What does it do?*
Measures voltage on a scale beginning with zero
Want to be in the green arc
Voltmeter measures in volts
Indicates the voltage of the working alternator system
A working alternator system must maintain voltage slightly higher than battery voltage
