J
JorgensenSteam
Guest
They use to use generators on automobiles, but they did not put out much voltage at low rpm, so they changed to alternators.
Both type devices move energized coils of wire or magnets past other coils of wire, inducing a current.
The current is the same, however, the generator has a commutator (the banded looking thing on the shaft) which reverses the polarity as the generator revolves, thus producing a voltage that does not change polarity (DC = direct current).
An alternate does not have a commutator, but only needs two slip rings, and produces alternating current and voltage that changes polarity as the alternator rotates. Direct current is produced by passing the alternating current through a bridge rectifier circuit, which has the mechanical analogy of a check valve.
Here is a nifty Cretors I ran across at a local Electrical Contractors office a few weeks ago.
If you push the button, an air compressor comes on, the engine runs, and the generator powers the street lights.
I told them I need to come over and take some measurements.
Both type devices move energized coils of wire or magnets past other coils of wire, inducing a current.
The current is the same, however, the generator has a commutator (the banded looking thing on the shaft) which reverses the polarity as the generator revolves, thus producing a voltage that does not change polarity (DC = direct current).
An alternate does not have a commutator, but only needs two slip rings, and produces alternating current and voltage that changes polarity as the alternator rotates. Direct current is produced by passing the alternating current through a bridge rectifier circuit, which has the mechanical analogy of a check valve.
Here is a nifty Cretors I ran across at a local Electrical Contractors office a few weeks ago.
If you push the button, an air compressor comes on, the engine runs, and the generator powers the street lights.
I told them I need to come over and take some measurements.