Electromagnet Design

[Robert Blass]

Electromagnet Design Question.

I have a power source of either an actual car battery of around 600
Cold Cranking Amps OR a power supply which is rated to be equal to
that of a car battery [it's used to power devices that would normally
be connected to a cigarette lighter adapter inside of a car]

What I really am asking is a few very basic question about the design.

1. What kind of core metal material would be best from both a safety
and performance standpoint?
2. Should I measure and adjust the amp's or simply go with what I
have.?
3. What would be an appropriate amount of amps to test with? Something
that wouldn't kill me via the amps or the heat created?
4. How many turns?
5. Should the metal core be straight like a nail or should I curve it
around in the shape of a U or even a Teardrop?
6. If curved around, should I connect the power to both the ends and
the curved portion or are the various images of this I have seen just
exaggerating the design?

I'm trying to learn some concepts regarding electro magnetism.

Thanks.

 

[Jon Slaughter]

"Robert Blass" <blame@messenger.xcx> wrote in message
news:vlshe4dhsc7jvgpa0b49rq0iu7f1f79b0c@xxx.org...

Electromagnet Design Question.

I have a power source of either an actual car battery of around 600
Cold Cranking Amps OR a power supply which is rated to be equal to
that of a car battery [it's used to power devices that would normally
be connected to a cigarette lighter adapter inside of a car]

What I really am asking is a few very basic question about the design.

1. What kind of core metal material would be best from both a safety
and performance standpoint?
2. Should I measure and adjust the amp's or simply go with what I
have.?
3. What would be an appropriate amount of amps to test with? Something
that wouldn't kill me via the amps or the heat created?
4. How many turns?
5. Should the metal core be straight like a nail or should I curve it
around in the shape of a U or even a Teardrop?
6. If curved around, should I connect the power to both the ends and
the curved portion or are the various images of this I have seen just
exaggerating the design?

I'm trying to learn some concepts regarding electro magnetism.

Then the best way is to experiment.

Just make sure you use enough turns so that the resistance is high enough to
prevent a huge current. e.g., use an ohm meter to measure the resistance and
plug it into ohms law. I = V/R. If V = 12 and R = 1 Ohm then I = 12A. The
power dissipation in the wire will be 144W. This is enough to get warm and
then hot pretty quick.

(note that 1 ohm is a lot of wire if it is thick. I wouldn't draw mess with
anything over 30 amps(R about 1/3 Ohm) to start with... if that(you can get
a decent magnet to play around with with just a few amps))

Most of all use your brain and think about what you are trying to do and
what is going on.

 

[Jon Slaughter]

"Robert Blass" <blame@messenger.xcx> wrote in message
news:q88ie41gmbbk300brujm12amifol5a113d@xxx.org...

On Sun, 5 Oct 2008 12:24:24 -0500, "Jon Slaughter"
Jon_Slaughter@Hotmail.com> sayd the following:


"Robert Blass" <blame@messenger.xcx> wrote in message
news:vlshe4dhsc7jvgpa0b49rq0iu7f1f79b0c@xxx.org...
Electromagnet Design Question.

I have a power source of either an actual car battery of around 600
Cold Cranking Amps OR a power supply which is rated to be equal to
that of a car battery [it's used to power devices that would normally
be connected to a cigarette lighter adapter inside of a car]

What I really am asking is a few very basic question about the design.

1. What kind of core metal material would be best from both a safety
and performance standpoint?
2. Should I measure and adjust the amp's or simply go with what I
have.?
3. What would be an appropriate amount of amps to test with? Something
that wouldn't kill me via the amps or the heat created?
4. How many turns?
5. Should the metal core be straight like a nail or should I curve it
around in the shape of a U or even a Teardrop?
6. If curved around, should I connect the power to both the ends and
the curved portion or are the various images of this I have seen just
exaggerating the design?

I'm trying to learn some concepts regarding electro magnetism.


Then the best way is to experiment.

Just make sure you use enough turns so that the resistance is high enough
to
prevent a huge current. e.g., use an ohm meter to measure the resistance
and
plug it into ohms law. I = V/R. If V = 12 and R = 1 Ohm then I = 12A. The
power dissipation in the wire will be 144W. This is enough to get warm and
then hot pretty quick.

(note that 1 ohm is a lot of wire if it is thick. I wouldn't draw mess
with
anything over 30 amps(R about 1/3 Ohm) to start with... if that(you can
get
a decent magnet to play around with with just a few amps))

Most of all use your brain and think about what you are trying to do and
what is going on.


With all of what you said in mind, wouldn't my use of a car battery be
very dangerous to me?

No.. unless you short the battery and it overheats and explodes. 12V is not
enough voltage to cause shock. You can walk up to a battery and grab both
ends... even wet... but if you drop a wrench across the terminals it will
either melt or possibly explode(from the hydrogen given off and the heat).

Also that power supply which is 12 volts puts out about 12-15 amps.
With that being the case I would assume it would be safe?

You need to learn ohms law, V = I*R. Know any 2 and you can solve the
other. For a car battery of about 12V or your power supply and with, say, R
= 1 Ohm, I = 12/1 = 12A. It doesn't matter which type of supply it is except
that the power supply *might* be safer since it probably will have over
current protection or smoke before it reaches the output capacity of a
battery.

So if you have the power supply then you can use it and it's probably the
best option unless you need more current.

And you're also saying that as long as I use a ton of windings that I
should be relatively safe as far as heat and melt down is concerned?

Trust me, I don't want to burn myself or catch something on fire..

I need some baby steps. I hope to make the magnet bigger but with
safety as a goal too.

Baby steps is fine... but you also have to learn to think for yourself.

Recheck and triple check connections but don't let fear prevent you from
progress. Although if you don't have any knowledge of electricity it can be
dangerous.

Two things can cause damage and in some sense they are identical(or at least
related). They are voltage and current. Almost everything you need to know
is summed up in ohms law: V = I*R. Read about it on the web.

V is dangerous when whatever is producing it can also sustain a large
current. Such as with a car battery. 12V is not enough to shock you but is
enough to make the battery explode if it's terminals are shorted(I = 12/~0 =
very large and dangerous current that can burn and cause fire or
explosions(in the proper context))

100M volts can shock the hell out of you but in some cases can't cause any
real damage. Static electricity is an example of this but power lines is a
counter example.

Just be careful not to short the battery or power supply(although it might
be more forgiving) an you will be ok. If you are not sure then just be ready
to pull the wire off the connector as fast as possible... in fact you should
first only quickly tap the wire to the terminal and see if it sparks... if
it does you can get an idea how much current you are pulling.

In fact it's best to have something that can measure the current or to have
a power supply that can display it.

I would be concerned with damage to media, like my hard drive
platters. So should I do this far away from the computer or is there
some kind of shielding I could make or buy for the computer and other
recorded media?

No. Don't worry about it. It's not all that dangerous as you think... just
be cautious and check for things being warm and get ready to disconnect
stuff. It's not like your making a bomb...

 

[Jasen Betts]

On 2008-10-05, Jon Slaughter <Jon_Slaughter@Hotmail.com> wrote:

No.. unless you short the battery and it overheats and explodes. 12V is not
enough voltage to cause shock. You can walk up to a battery and grab both
ends... even wet... but if you drop a wrench across the terminals it will
either melt or possibly explode(from the hydrogen given off and the heat).

If wet enough you'll feel it.

Bye.
Jasen

 

[Robert Blass]

On Sun, 5 Oct 2008 15:40:40 -0500, "Jon Slaughter"
<Jon_Slaughter@Hotmail.com> sayd the following:

In fact it's best to have something that can measure the current or to have
a power supply that can display it.

I know there is a meter for V, I and R but are there meters that
measure all three?

I have one of those multi-meters, will that be good to help?
I think I measures Volts and Ohms.

Do the math since I have V and R?
thanks again

 

[Jon Slaughter]

"Robert Blass" <blame@messenger.xcx> wrote in message
news:n57ke4p1fqekk1bhldvghv3884vbc8ele6@xxx.org...

On Sun, 5 Oct 2008 15:40:40 -0500, "Jon Slaughter"
Jon_Slaughter@Hotmail.com> sayd the following:

In fact it's best to have something that can measure the current or to
have
a power supply that can display it.


I know there is a meter for V, I and R but are there meters that
measure all three?

I have one of those multi-meters, will that be good to help?
I think I measures Volts and Ohms.

They are called multimeters. Read the manual to figure it out. (not that
it's difficult but you might learn something)

Do the math since I have V and R?

Yes, basic math. Do you know it?

 

[Robert Blass]

On Sun, 5 Oct 2008 12:24:24 -0500, "Jon Slaughter"
<Jon_Slaughter@Hotmail.com> sayd the following:

"Robert Blass" <blame@messenger.xcx> wrote in message
news:vlshe4dhsc7jvgpa0b49rq0iu7f1f79b0c@xxx.org...
Electromagnet Design Question.

I have a power source of either an actual car battery of around 600
Cold Cranking Amps OR a power supply which is rated to be equal to
that of a car battery [it's used to power devices that would normally
be connected to a cigarette lighter adapter inside of a car]

What I really am asking is a few very basic question about the design.

1. What kind of core metal material would be best from both a safety
and performance standpoint?
2. Should I measure and adjust the amp's or simply go with what I
have.?
3. What would be an appropriate amount of amps to test with? Something
that wouldn't kill me via the amps or the heat created?
4. How many turns?
5. Should the metal core be straight like a nail or should I curve it
around in the shape of a U or even a Teardrop?
6. If curved around, should I connect the power to both the ends and
the curved portion or are the various images of this I have seen just
exaggerating the design?

I'm trying to learn some concepts regarding electro magnetism.


Then the best way is to experiment.

Just make sure you use enough turns so that the resistance is high enough to
prevent a huge current. e.g., use an ohm meter to measure the resistance and
plug it into ohms law. I = V/R. If V = 12 and R = 1 Ohm then I = 12A. The
power dissipation in the wire will be 144W. This is enough to get warm and
then hot pretty quick.

(note that 1 ohm is a lot of wire if it is thick. I wouldn't draw mess with
anything over 30 amps(R about 1/3 Ohm) to start with... if that(you can get
a decent magnet to play around with with just a few amps))

Most of all use your brain and think about what you are trying to do and
what is going on.

With all of what you said in mind, wouldn't my use of a car battery be
very dangerous to me?

Also that power supply which is 12 volts puts out about 12-15 amps.
With that being the case I would assume it would be safe?

And you're also saying that as long as I use a ton of windings that I
should be relatively safe as far as heat and melt down is concerned?

Trust me, I don't want to burn myself or catch something on fire..

I need some baby steps. I hope to make the magnet bigger but with
safety as a goal too.

I would be concerned with damage to media, like my hard drive
platters. So should I do this far away from the computer or is there
some kind of shielding I could make or buy for the computer and other
recorded media?

THANKS for your help.