Build a simple electromagnet?

Question

i have to build an electromagnet for physics and there are some requirements.first of all the larget voltage i am aloud to use is only 1.5 volts. and to get an A(which i desperatly need)i need to beable to pick up at least 200 grams(40 nickles, 200 paperclips etc...)i am wondering what is the best battery to use,ie triple A, double A, C or whatever, what size wire works best, and how many turns i need around my steel/iron bar,and how to strengthen the current. any help is appreciated

Answer 1

Like the previous posters said, the larger the battery the better. If you cannot get a large battery, multiple size D batteries connected in parallel will still provide 1.5 volts but at much greater current capacity.

I would go to Radio Shack and buy Catalog #: 278-1218 hook up wire. Then I would go to the hardware store. Find the largest diameter bolt that they carry, and get it in the longest length they have to use as your core.

I would unroll the wire and cut it in half. Wind one piece of wire around the core. Test your magnet. If it is not strong enough, then wrap the other piece around also; then connect the 2 windings together in parallel and retest.

Hints for winding:

Be careful that all windings have current flow in the same direction, clockwise or counter clockwise. If you accidentally get confused after you start winding and start winding in the opposite direction then those windings will negate the effect of the previous. If you use the second wire then it should nearly double the strength. If instead it weakens it then you have the current in the second layer going in the wrong direction and you ned to reverse its connections.

Windings have a habit of coming loose and tangling. So have electrical tape handy when winding. As soon as you finish each layer of windings wrap the tape around the entire thing to hold all of those windings in place. Then start wrapping the next layer. Wrap the last layer also.

Answer 2

This is a very simple operation. use a screwdriver 6 inches long as your steel bar,use a wire # 18, peel of the ends, turn the wire all over the screwdriver from the base of the handle to the end, use a new battery size D and connect the two peel of ends to the battery one end at the + the other at the - and your temporary electromagnet is ready. If you want to have more power, make the loop tighter to each other than possible.
Good luck

Answer 3

I would recommend the hobby battery suggested above. I did a similar experient in elementary science, but it was so many years ago I couldnt tell you exactly how to build this. I do know that I would use a hard metal for the core of the magnet, perhaps a STEEL rod. Secondly, the amount of coils DOES effect the magnets strength. Also, use a solid wire to wrap around the core, make sure its not made of of strands.

To be safe I would build one at home, and try to pick up the mass or similar at home.

Answer 4

You need as many turns of 28 to 32 GA. enameled (insulated) wire as you can wrap around the iron core, to decrease the current in the wire by increasing the resistance. Bigger gage is smaller wire. Inductance offers no resistance to direct current & large wire diameters will quickly drain or short out your battery. This will only pick up items containing iron so stick with paper clips, as nickles are not attracted by magnetism.
Previous posters are correct, use the larger battery. I suggest you install a switch to apply current to the magnet when you wish to use it. It will not last long in the continous on state.

Answer 5

A 1.5 volt "D" cell has a bit more capacity than the smaller batteries, so it will last longer, particularly if it is an alkalyne cell.

It is good to keep the voltage low for safety reasons. Just follow the directions and safety cautions in the attached URL and I have no doubt you will succeed.

Afterthought: The "hobby" battery Mr. Hildebrand shows is better than the "D" cell I suggested because it has even more capacity and terminals for ease of connection. I didn't know they still made those.

Answer 6

A "D" battery will supply the most power in the little cartridge type batteries. If you really want to make sure use one of these:
http://bigboystoysnm.com/index.php?main_page=product_info&products_id=1228
It will give you far more current. You may have to use a much longer wire to limit the current flow but if this is uded for windings you'll have a much more powerful magnet to use.

Answer 7

Crane manufacturers and end users today have the ability to apply a variety of new control strategies based on variable speed drives with powerful built in crane control applications. Making the best choice in control strategies can give important advantages for both safety and control operations.