magnets?
- Thread starter fireboy81
- Start date
i see no reason why they wouldn't.
a magnet is a magnet is a magnet.
if you placed a south pole of an electromagnet against the south pole of a permanent magnet then yes, like poles repel.
it seems like it would.
the limiting factor would be the flux density.
if the PM is at its maximum density then any increase in coil current will not increase it. the above isn't a misprint.
you are talking about winding a coil around a PM to increase its strength, right?
Yes, and if you reverse the current through the electromagnet then it will attract the magnet. That's how most speakers work. You have to be carefull though. It is possible to overwhelm permanent magnets such that you demagnetize them, especially when the electromagnet and magnet are in repulsion.
kevin,
the limiting factor will be core saturation.
the fields will add and subtract, but only up to the saturation point of the core.
this effect is non existant in air core transformers.
yes, i know, we aren't talking about transformers, but the effect is still the same.
i cannot seem to recall the terms to search on to provide any links.
edit:
here is something at least:
http://www.physicsforums.com/archive/index.php/t-111321.html
and this:
http://www.beigebag.com/case_xfrmer_4.htm
the limiting factor will be core saturation.
the fields will add and subtract, but only up to the saturation point of the core.
this effect is non existant in air core transformers.
yes, i know, we aren't talking about transformers, but the effect is still the same.
i cannot seem to recall the terms to search on to provide any links.
edit:
here is something at least:
http://www.physicsforums.com/archive/index.php/t-111321.html
and this:
http://www.beigebag.com/case_xfrmer_4.htm
The industrial electromagnets are using alloys with higher saturation ability, higher magnetization and lower remanence. You must also consider whether the magnet is to run on DC or AC power. If the magnet is to run on AC, and the application is critical, then the core should be composed of isolated stripes or wires due the limitation of eddy currents, hysteresis losses, and the additional inductive impedance of your magnet.
It depends on the potential usage of such electromagnet. Currently I've no idea, what purpose such electromagnet is supposed to serve for.
Use your solid half inch iron bar. Wrap the bar in wire. The more turns, the greater the strength of your magnet. Up to a point (where it either saturates or you start limiting current due to the wire resistance) You need to be aware of these things:
- The wire will get hot (and even glow!) if you don't use enough turns to provide enough resistance to limit the current. I = V/R. Use enough turns to make sure you don't exceed the current-carrying rating of the wire, lest it melt.
- Thicker wire has a lower resistance per foot and a greater ability to dissipate heat.
- With thinner wire you can usually squeeze more turns on your core.
Other than that, your best bet is to wind some magnets with different gauge wires and see if you can get the strength you need given your core size.
Have fun!
just for fun my dear friend im teaching the kids at a school for disadvantaged about how to make different types of water pumps and using magnets was one of there ideas so i said we would try to find out how to make our own motor out of old scrap bicycles and scrap iron and wire and stuff gonna try use a gearing system to attach it to a centrifugal pum see how it goes prob wont work but they love trying lol just my physics is a bit rusty as almost eight years outta school thanks for your help
thanks
hey thanks im gonna just use some copper wire i got from flexing which is insulated we have already established how to use the whole iron nail part and worked well now we trying to rig up a switch to atract and repel each other as they rotate past eachother (the permanent past the electromagnet) but was trying to get as much repulsion from the electromagnet as i can to get the wheel moving stronger. thanks for your help though will try the thicker iron core see what happens
hey thanks im gonna just use some copper wire i got from flexing which is insulated we have already established how to use the whole iron nail part and worked well now we trying to rig up a switch to atract and repel each other as they rotate past eachother (the permanent past the electromagnet) but was trying to get as much repulsion from the electromagnet as i can to get the wheel moving stronger. thanks for your help though will try the thicker iron core see what happens
That's a good idea. Little strips of black electrical tape works well too, but tends to get mangled after a few minutes of running.