AC Motors

[yakobiana]

Hello
I hope my question will not be stupied.
I dont understand how can it be that ac motors dont need groung ponit
as
in DC motors.
Maby i dont understand the meening of ac current , does ac current
needs groud
to work and if yed than whay? i can understand why it is needed for dc
current but why for ac ?

If someone can light my eyes please.

yakobiana@leadcom-is.com

 

[John Popelish]

yakobiana wrote:

Hello
I hope my question will not be stupied.
I dont understand how can it be that ac motors dont need groung ponit
as
in DC motors.

Ground has nothing to do with motor operation, either AC or DC.
Motors need a source of potential difference (voltage) to provide the
electromotive force to drive current through the motor. Every time
the coils turn over (with respect to the magnetic field), the voltage
needs to be reversed. In a DC motor, this reversing is done with
brushes and commutators, or with solid state switches. In AC motors,
the reversal comes from the sine wave voltage changing polarity.

Maby i dont understand the meening of ac current , does ac current
needs groud
to work and if yed than whay? i can understand why it is needed for dc
current but why for ac ?

Dc motors can run off a battery that has no connection to ground. AC
motors can run off a transformer winding that has no connection to
ground.

If someone can light my eyes please.

yakobiana@leadcom-is.com

--
John Popelish

 

[John Popelish]

yakobiana wrote:

Hello
I hope my question will not be stupied.
I dont understand how can it be that ac motors dont need groung ponit
as
in DC motors.
Maby i dont understand the meening of ac current , does ac current
needs groud
to work and if yed than whay? i can understand why it is needed for dc
current but why for ac ?

If someone can light my eyes please.

yakobiana@leadcom-is.com

This may help:
http://electronics.howstuffworks.com/framed.htm?parent=motor.htm&url=http://e-www.motorola.com/collateral/MOTORPRINTUT.html
--
John Popelish

 

[Peter Bennett]

On Fri, 19 Sep 2003 12:36:24 GMT, John Popelish <jpopelish@rica.net>
wrote:

yakobiana wrote:

Hello
I hope my question will not be stupied.
I dont understand how can it be that ac motors dont need groung ponit
as
in DC motors.

<snippage>

Maby i dont understand the meening of ac current , does ac current
needs groud
to work and if yed than whay? i can understand why it is needed for dc
current but why for ac ?

Dc motors can run off a battery that has no connection to ground. AC
motors can run off a transformer winding that has no connection to
ground.

We often _call_ one side of a DC supply "ground", whether or not it is
actually connected to the earth, whereas with AC power wiring,
"ground" is a non-current-carrying conductor. In AC wiring, the
equivalent to the DC "ground" is often called "neutral" - perhaps this
is the cause of your confusion?


--
Peter Bennett VE7CEI
GPS and NMEA info and programs: http://vancouver-webpages.com/peter/index.html
Newsgroup new user info: http://vancouver-webpages.com/nnq

 

[John Popelish]

Peter Bennett wrote:

On Fri, 19 Sep 2003 12:36:24 GMT, John Popelish <jpopelish@rica.net
wrote:

yakobiana wrote:

Hello
I hope my question will not be stupied.
I dont understand how can it be that ac motors dont need groung ponit
as
in DC motors.

snippage

Maby i dont understand the meening of ac current , does ac current
needs groud
to work and if yed than whay? i can understand why it is needed for dc
current but why for ac ?

Dc motors can run off a battery that has no connection to ground. AC
motors can run off a transformer winding that has no connection to
ground.

We often _call_ one side of a DC supply "ground", whether or not it is
actually connected to the earth, whereas with AC power wiring,
"ground" is a non-current-carrying conductor. In AC wiring, the
equivalent to the DC "ground" is often called "neutral" - perhaps this
is the cause of your confusion?

Your mind reading skills may be lots better than mine.

--
John Popelish