Physics Help Forum Neodymium magnet and electromagnet experiment

 Electricity and Magnetism Electricity and Magnetism Physics Help Forum

Nov 23rd 2017, 07:14 PM   #31
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Join Date: Apr 2017
Posts: 401
 Originally Posted by yafimski Hi oz93666, Sadly I am in the Netherlands. Only bikes here :/ I don't have somewhere to get a car battery, but I also didn't find one on ebay/amazon when I searched. Can you recommend a place to buy one online...?
I did live in The Netherlands for a few years many cars everywhere ... and many shops selling car batteries , scrap yards with old batteries ...

Cannot buy lead acid battery online , postage would cost more than the battery!!

It really would help if you gave more details of what you want to do , it could probably be powered directly with mains electricity (230V)...

Last edited by oz93666; Nov 23rd 2017 at 07:16 PM.

 Nov 24th 2017, 12:20 AM #32 Junior Member   Join Date: Sep 2017 Posts: 25 Dear oz93666, I am attaching a photo to better describe what I wish to achieve as the experiment. The trial I made so far involved the nail, copper coil, and simple 9v battery, which turned out way too weak. Does this help to figure out which power supply I need...? Thanks! Attached Thumbnails
Nov 24th 2017, 04:46 AM   #33
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Join Date: Apr 2017
Posts: 401
 Originally Posted by yafimski Dear oz93666, I am attaching a photo to better describe what I wish to achieve as the experiment. The trial I made so far involved the nail, copper coil, and simple 9v battery, which turned out way too weak. Does this help to figure out which power supply I need...? Thanks!
Thanks...I'm a little clearer ... you want to achieve some movement in a ring magnet ... My first comment is the coil needs to be much bigger . put "solenoid coil " in ebay and you'll find many , this one is 2 euros ...

or this one 3 euros ...it takes only 0.25 A .. possible with small domestic batteries ...it has many hundreds or perhaps thousands of turns in the coil...It would be very difficult , more expensive and time consuming for you to make one yourself that will produce the same effect

Last edited by oz93666; Nov 24th 2017 at 04:50 AM.

 Nov 24th 2017, 11:18 AM #34 Junior Member   Join Date: Sep 2017 Posts: 25 Thanks! I found these: coil 1 coil 2 coil 3 which one would you recommend for the biggest effect?
 Nov 24th 2017, 06:34 PM #35 Senior Member   Join Date: Apr 2017 Posts: 401 coil 1 is $2.34 free postage .. coil 2 is$15 +46 postage (rule #1 ,never buy from US postage is a joke) coil 3 is $15 +$25 postage Since you are just experimenting I would suggest you buy perhaps 3 of the cheapest coils , coil 2 and 3 are not better quality, coil 1 looks fine , I would get that , and a few others types for 2/3 euros each ... You need to also think about power ...surely you have an old laptop charger , or a charger for an electric drill these would be perfect to try with the ebay coils.... any sort of charger
 Nov 25th 2017, 01:54 AM #36 Junior Member   Join Date: Sep 2017 Posts: 25 Thanks! I'm ordering them About the charging, can you explain what's the connection sequence of these elements? Maybe a quick sketch of how the charger should connect to the coil..? Or maybe it's a straight forward +/-. Also - do I still need a nail to get it electromagnetic enough in order to effect the neomagnet?
 Nov 25th 2017, 04:05 AM #37 Senior Member   Join Date: Apr 2017 Posts: 401 just plug the charger strait into the coil ...it would help to buy a multimeter , then you can see what amps and voltage you have ...another 4or 5 euros from ebay ....I you probably don't need the nail , depending on the coil design ...
 Nov 25th 2017, 05:40 AM #38 Junior Member   Join Date: Sep 2017 Posts: 25 Thanks a lot! Will update with results!
 Jan 13th 2018, 08:01 AM #39 Junior Member   Join Date: Sep 2017 Posts: 25 Hi, Sorry to ask these simple questions again but I'm not sure what to do. I have the 'coil 1' I mentioned in the above posts. It's a tiny solenoid with DC12V on it. I tried to attach the coil to the +/- of the battery and just bring it close to the magnet but it didn't differ from my previous trial - meaning the magnet just doesn't seem to be affected by the coil's magnetic field. The battery I used is still the 9v. Should I split an old laptop charge's cable and connect it to the wall? Thanks
 Jan 26th 2018, 11:48 AM #40 Junior Member   Join Date: Sep 2017 Posts: 25 oz93666 Do you mean I should split the end of a laptop charger, attach the solenoid to it and plug it into the wall? Isn't that dangerous...? Thanks