Unit 3 Flashcards
Measure of the force in an electrical system that causes current flow; measure of EMF
voltage
typical voltage
12V or 24V
Measure of electricity through a conductor
current
unit of current
amps
end of battery that electrons are attracted to
positive terminal
unit of resistance
ohm
what is resistance?
the “friction” an electron encounter as it flows
EMF must be required
which of the following best described the contributing factors to thermal runaway in a nickel-cadmium battery installed in an aircraft?
low internal resistance intensified by high cell temperatures and a high current discharge/charge rate in a constant potential charging system
what do rectifiers do
AC to DC
what do rectifiers have
transformer, stack, and cabinet
what do inverters do
increase DC voltage, then DC to AC
how is electrical energy transferred from one circuit to another without any connections?
induction
how is the voltage output of an alternator regulated?
controlling the voltage output of the DC exciter
solid state transistor and a “zener diode” to regulate voltage
purpose of circuit breakers
designed to protect the circuit from damagingly high levels of current flow
tell me about DC
single direction
constant polarity
changes magnitude when current turns on and off
tell me about AC
direction of current changes
easy to generate
easily stepped up/down with transformers
with an electromagnet, what affects the strength?
winding a coil around a soft iron core
where to find lead acid batteries
piston
NiCad CONS
low internal resistance
long life
expensive
prone to thermal runaway
where to find NiCad batteries
turbine
what is useful load
crew, usable fuel, passengers, and cargo
independent braking system
pressure only as great as foot pressure applied
boosted brakes
actuating system that augments force with hydraulic pressure
aircraft with boosted brakes
medium to large aircraft that do not require a full power system
