Chapter 4 Electrical Systems Flashcards
Load meter needle deflections less than the summed amperage of active and properly working electrical equipment imply that the ___ will eventually be ___.
Battery, drained
The load meter shows the ___ pulled from the alternator by the airplane’s electrical system.
current
Between the positive terminal of the battery and the primary bus is an ammeter, called a ___ ammeter.
Charge-discharge
Amps are a measure of ___ flow.
current
What part of the airplane is generally used as a ground?
metal frame
How long will a typical C-172’s battery last if the alternator fails (with all unnecessary equipment turned off)?
30 minutes
A negative needle deflection on the charge-discharge ammeter usually implies that the [battery/alternator] is supplying the primary bus with electrical current.
battery
While airplane batteries are rated at 12 or 24 volts, airplane electrical systems (their alternators) are rated for ___ or ___ volts.
14,28
Voltage regulators help alternators maintain a ___ voltage output under varying RPM conditions
Constant
The greater the ___ in a line, the greater the amount of ___ that flows.
voltage, current
Your high-voltage warning light may be a sign that your _____ is putting out excessive voltage or your voltage regulator is malfunctioning.
alternator
A load meter is located between the ___ and the ___ of the electrical system.
alternator, primary bus
Load meters with a zero or full-left deflection indicate the alternator [is/isn’t] providing current to the primary bus
isn’t
If the battery is dead, the ___ isn’t going to work.
alternator
Suppose the load meter’s needle deflection is greater than the needs of the electrical equipment. This can lead to…
Evaporating battery fluid or battery and electrical fires
As the name implies, the charge-discharge ammeter tells you if electrical current is flowing into or out of the ___
battery
If you need the equipment that was disable by the popped circuit breaker, a good recommendation is to never reset the circuit breaker ___
more than one time
If faced with an errant voltage regulator in flight which forces you to deactivate the alternator, what should you do?
Turn off all nonessential electrical equipment
A zero reading on the load meter (a full left deflection) means that the alternator [is/isn’t] providing current to the electrical equipment.
isn’t
Most airplane operation manuals suggest that after approximately ___ of cruising flight, the ammeter needle should return to within a two-needle-width deflection from center on the positive (+) or charging side.
30 minutes
If the voltage regulator goes bad and the alternator produces too much voltage, how do you deactivate the alternator?
Turn off the alternator switch or pull the Main Alternator fuse.
A needle deflection on the ___ side means current is flowing out of the battery onto the primary bus
negative (-)
With two radios, two nav radios, one electric gyro, a transponder and an autopilot in use, a 16 amp deflection should be shown on the load meter. A needle deflection less than 16 amps implies that the ___ isn’t providing enough current to run the equipment
alternator
During flight with the electrical equipment in use, a full left deflection of the load meter needle is similar to a charge-discharge ammeter reading pointing to the ___ side of its scale.
negative (-)
If your airplane has a low-voltage light, it can illuminate…
During low engine idle, and When the alternator has been taken offline
Normally, the needle of the charge-discharge ammeter should be resting near the ___ or ___ mark. This implies that the battery is neither being charged nor discharged (a good sign)
zero, center
If the alternator fails in flight, the _____ must power all of your electrical equipment.
battery
Electrons flow from the ___ to the ___ side
Negative, positive
Alternators need a little bit of electricity running through them before they’ll start producing electricity. This small amount of electrical prime is called the ___
Alternator field current
A positive deflection of the charge-discharge ammeter usually implied that the battery is being…
charged
Radios typically consume ___ amp(s) of current while receiving about ___ amp(s) while transmitting
one-half, 5
After startup, the battery is sure to be slightly drained. You can expect to see a ___ needle deflection of 5-7 needle widths on the ammeter right after engine start
Positive (+)
Circuit breakers protect electrical equipment and wires from receiving more ___ than they can safely handle
current
a 35 amp hour battery should (in theory) provide ___ amps of continuous current to the electrical system for one hour
35
