Motors

I don't know if this is the right place to ask this, but I'm wondering how drills and circular saws work?.. How they turn electricity into rotational
motion of the tool. Chainsaws, weedwackers, and such are easy - they use internal combustion and turn that combustion energy into rotational motion through a piston, cylinders and rods. I do not know how you turn electricity into rotational motion in tools like a drill or a circular saw. Brian White
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Brian White wrote:

Some info here:
> http://electronics.howstuffworks.com/motor.htm
Dean
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in article 4_zee.8229\$db7.4552@trnddc01, Brian White at snipped-for-privacy@hotmail.com wrote on 5/5/05 6:44 PM:

Use a library or an encyclopedia!
Bill
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I'm wondering how

into rotational

easy - they use

rotational motion

you turn

or a circular saw.

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Brian White at snipped-for-privacy@hotmail.com

Power comes into the tool and this causes the motor to turn, unless you need the drill for a project that absoulely has to be done the next morning,and it is late and there is no other drill available. Then the drill motor merely turns electricity into heat.
I have an entry-level college physics book that explains motor therory well, but surely there is something on the net. Try google.
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saw.
When you have an electric current perpendicular to a a magnetic field , there is a force produced between the two (which is perpendicular to both). In a motor, the field is on one part (say the stationary part as is the case for for many small motors) and the current is in the winding on the other (rotating) part. Then torque (rotational force) is produced causing motion and electrical energy is converted to mechanical energy. This is very oversimplified but it is the same basic principle that you see in your car starter, alternator, household motors and industrial motors and generators. Actually chain saws and weedwhackers are more complicated machines than electric motors.
There is a lot of basic information in a simple format on line or in pretty well all encyclopedias and libraries as mentioned by others who have answered.
--
Don Kelly
snipped-for-privacy@peeshaw.ca
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this format, some or all of this message may not be legible.
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in article ZZVee.1260255\$6l.255772@pd7tw2no, Don Kelly at snipped-for-privacy@peeshaw.ca wrote on 5/6/05 7:46 PM:

I think that the next time asks such a question, my reply will be
F = I x B
and hope I have the sign correct. :=)
Bill
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<HTML> <HEAD> <TITLE>Re: Motors</TITLE> </HEAD> <BODY> in article ZZVee.1260255\$6l.255772@pd7tw2no, Don Kelly at snipped-for-privacy@peeshaw.ca wrote on 5/6/05 7:46 PM:<BR> <BR> &gt; When you have an electric current perpendicular to a a magnetic field ,<BR> &gt; there is a force produced between the two (which is perpendicular to both).<BR> &gt; In a motor, the field is on one part (say the stationary part as is the case<BR> &gt; for for many small motors) and the current is in the winding on the other<BR> &gt; (rotating) part. Then torque (rotational force) is produced causing motion<BR> &gt; and electrical energy is converted to mechanical energy.<BR> <BR> I think that the next time asks such a question, my reply will be<BR> <BR> <B>F</B> = <B>I </B>x <B>B<BR> <BR> </B>and hope I have the sign correct. :=)<BR> <BR> Bill </BODY> </HTML>
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Re: MotorsHowever, Lorentz is "magic" and that doesn't answer the question - we may both have problems chasing down the question of "why?" -- Don Kelly snipped-for-privacy@peeshaw.ca remove the urine to answer
have an electric current perpendicular to a a magnetic field ,<BR>&gt; there is a force produced between the two (which is perpendicular to both).<BR>&gt; In a motor, the field is on one part (say the stationary part as is the case<BR>&gt; for for many small motors) and the current is in the winding on the other<BR>&gt; (rotating) part. Then torque (rotational force) is produced causing motion<BR>&gt; and electrical energy is converted to mechanical energy.<BR><BR>I think that the next time asks such a question, my reply will be<BR><BR><B>F</B> = <B>I </B>x <B>B<BR><BR></B>and hope I have the sign correct. :=)<BR><BR>Bill </BLOCKQUOTE></BODY></HTML>
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Re: Motors
have an electric current perpendicular to a a magnetic field ,<BR>&gt; there is a force produced between the two (which is perpendicular to both).<BR>&gt; In a motor, the field is on one part (say the stationary part as is the case<BR>&gt; for for many small motors) and the current is in the winding on the other<BR>&gt; (rotating) part. Then torque (rotational force) is produced causing motion<BR>&gt; and electrical energy is converted to mechanical energy.<BR><BR>I think that the next time asks such a question, my reply will be<BR><BR><B>F</B> = <B>I </B>x <B>B<BR><BR></B>and hope I have the sign correct. :=)<BR><BR>Bill </BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>
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Re: MotorsI have a problem with what you have said below. It appears not to be gerrmane to electric motors and more of a proposed return to an aether concept. Then I saw a reference to Beardon and all becomes clear - not lucid -just where you are coming from. By the way, the background field for an electric motor is generally the magnetic field that is built into the design of the machine. Nothing to do with some elusive all pervading unknown quantity permeating space. -- Don Kelly snipped-for-privacy@peeshaw.ca remove the urine to answer
have an electric current perpendicular to a a magnetic field ,<BR>&gt; there is a force produced between the two (which is perpendicular to both).<BR>&gt; In a motor, the field is on one part (say the stationary part as is the case<BR>&gt; for for many small motors) and the current is in the winding on the other<BR>&gt; (rotating) part. Then torque (rotational force) is produced causing motion<BR>&gt; and electrical energy is converted to mechanical energy.<BR><BR>I think that the next time asks such a question, my reply will be<BR><BR><B>F</B> = <B>I </B>x <B>B<BR><BR></B>and hope I have the sign correct. :=)<BR><BR>Bill </BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>
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Don't know what you mean by a "weightless" arm, but if you have a disembodied arm trying to throw a tomato, the tomato _will_ be thrown, but the arm will also travel in the opposite direction. Conservation of momentum, equal and opposite reactions, etc. It is also how rockets work in space, (they 'throw' burning fuel) even without no air to push against. An electric motor will also work in space, but its frame will rotate in the opposite direction.
<snip rant>
This is an argument for the 'ether'. A long time ago everyone thought 'ether' pervaded all space and was necessary for light or whatever to propogate, as apparently you do. They did experiments to determine which way the ether flowed relative to the earth and surprise! They found there is no ether! A vacuum really does contain nothing.
--
-Mike

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Michael Moroney wrote:

Agreeing with your point and expanding on it:
The rocket fuel does have something to push against - the rocket. As the fuel expands. it pushes against all sides of whatever contains it and escapes at the vent. For the sake of discussion, say the vent is pointing "south" and the nose of the rocket is pointing "north" (north and south used only to indicate exactly opposite). The fuel expands and moves "south". The same force that pushes the fuel "south" also pushes the rocket "north".
I suspect "weightless" was intended to mean "massless". Maybe ??. And maybe (I'm speculating) he has the following in mind: In theory, if there could be such thing as a massless arm, then it wouldn't throw the tomato. F=MA ???
With a "real" weightless arm, if it can move it will throw the tomato. As an example, consider a mechanical arm shaped like a human arm, floating in space. In the palm of the hand is a tomato. On the back of the hand is our rocket from the previous example. The rocket pushes the hand, and the hand throws the tomato.
Ed
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This is what I was looking for (see below). So, to produce torque without an internal combustion engine, you use the same principle as an alternator or even a steam turbine generator. I was curious why internal combustion engines are so complicated with all of that linear force needing to be converted to torque. I had become curious about the rotary wankel engine and how it makes the process much simpler. Then I thought, why not use the same principle alternators use. Alas, it is already used. Simply put, it does not produce enough torque to be useable efficiently in cars where tremendous torque is needed. For instance, electric powered chainsaws are much weaker than ones that are gasoline powered with a cylinder. Now I understand. I wonder if they will ever come up with a better way to make engines where you don't need to convert linear forces like in an internal combustion engine into torque. The rotary wankel engine was a step in the right direction I believe. Any thoughts? Brian

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the
----------- The internal combustion engine has a better power to weight ratio than most electric motors and also elctric chainsaws are limited by their power supply. However, do not think that electric motors are inherently "weaker" than IC engines as it simply is not true. Note that electric motors of the order of 100,000 HP are not uncommon.
--
Don Kelly
snipped-for-privacy@peeshaw.ca
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