# How a Motor or Generator works?

#### Moni

How a Motor or Generetor works ???

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#### kyle_soule

Re: M/g

Originally posted by Moni
How a Motor or Generetor works ???
I'm assuming you mean an electric generator as opposed to a generator ran by fuel?

In this case I searched google and found this site:
How a generator works.

Also, if this is not what you wanted a google search (with quotes " ") will do wonders for you, the sites usually provide for pictures, which don't seem to work well on PF.

#### russ_watters

Mentor
Re: M/g

Originally posted by Moni
How a Motor or Generetor works ???
Since harnessing and creating electricity work the same way, apply electricity to a motor and it spins. Spin a motor and it becomes a generator.

Its just rotating electromagnets.

#### Moni

But what is the basic difference between AC and DC machines???

What is eddy current loss???

why tranformer rating is not KW why it is KVA???

#### russ_watters

Mentor
Originally posted by Moni
But what is the basic difference between AC and DC machines???

What is eddy current loss???

why tranformer rating is not KW why it is KVA???
ac is alternating current, dc is direct current (constant). KVA is used because KW doesn't take into account phase for ac.

Maybe you should use google. It sounds like you have a lot of basic questions and you can find some quick answers there.

#### dav2008

Gold Member
Yea...DC has a constant voltage(like when u connect a circuit to a battery...its always going to be , say, 12 Volts...(well not really since the battery has internal resistance, and i think the voltage goes down as the battery gets older...maybe not...))..
But in AC the voltage varies sinusoidaly...For example, most american outlets are 120 V and 60 hz..this means that the voltage goes between 120 and -120 60 times in a second...(correct me if im wrong, please..i might be mistaken on some details_)

#### drag

Hertz is a unit of frequency - a full
position - back AND forth.

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