Generators Amd Microphomes Flashcards
What do alternators do
Rotate a coil in a magnetic field
As the coil or magnet spins what does it induce
A current in the coil that changes direction every half turn
What do ac generators have instead of split ring commutator
Slip rings and brushes so the contacts don’t sway every half turn
What does this mean
They produce an alternating potential difference
What do dynamos have instead of slip rings
Split ring communicagor
What do dynamos produce
Direct currents
What do the split ring communicators do
Seal the connection every half turn to keep the current flowing in the same direction
What do oscilloscopes show
How the potential difference generated in the coil changes over time
What does the ac trace show
The line goes up and down crossing the horizontal axis
What does the dc line show
Stays above the axis because the pd is always positive
What does increasing the frequency of revolutions increase
The overall pd but also creates more peaks
What doe the height of a line show
The generated potential difference at the time
What are microphones
Loudspeaker in reverse
What do the sound waves hit
A flexible diaphragm That is attached to a coil of wire traps around a magnet
What does this cause the wire to do
Move the magnetic field which generates a current
