In a message dated 97-10-31 07:22:35 EST, jruwaldt@indiana.edu writes:
> I understand all that, but why do we call them "alternators", when they
> produce direct current?
Jim:
As a matter of fact, generators also produce AC voltage. The conversion to DC
is provided by segmented slip rings, rather than diodes. Just as the
generator rotates to complete the positive cycle and begin the negative, the
brushes slip from one segment to the other, reversing the polarity of the
output. The generator ouput is reversed by rotation, and reversed again by
the brushes, so the end result is a constant polarity output, or a pulsating
DC, just as in the alternator.
NOTE: The following contains NO LBC content!
For all you Steve Vai and Joe Satriani wanna-bes, this is how the humbucking
pickups on your guitars work. Each pickup consists of two seperate pickups,
wired together. The magnets in each are placed in opposite directions, the
south pole of one next to the north pole of the other. When a string is
plucked, the output produced by the magnets is of opposite polarity. However,
the wire coils are also wound in opposite polarity, so the signal is put back
in phase, and you get the full output. When electrical interference is
encountered, such as you get when playing in a room that is lit by
flourescent lights, the output signal generated the electrical fields cutting
through each winding is cancelled because of the polarity reversal of the
winding connections. The magnets are not involved in picking up interference.
Les Paul was a clever guy!
Dan (a frustrated Vai/Satriani wanna-be!) Masters
Alcoa, TN
'71 TR6---------3000mile/year driver, fully restored
'71 TR6---------undergoing full restoration and Ford 5.0 V8 insertion - see:
http://www.sky.net/~boballen/mg/Masters/
'74 MGBGT---3000mile/year driver, original condition
'68 MGBGT---organ donor for the '74
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