Need help with a school project

10 Mar 2024

Hello. I am currently a student and need help in the subject of electromagnetism. What can be the maximum weight a homemade electromagnet can carry given by the power source of a 2 x 1.5 AA Battery? Afterwhich, may I ask for the type of wire, core, and additional tips for creating this magnet?

Top Comments

dougw 8 months ago +1

Look up how much current your batteries can supply. Look up what is the smallest diameter wire that can carry that current. Based on the resistance of that wire calculate how much wire would it take for…

beacon_dave 8 months ago in reply to shabaz

...Very interesting video...

The follow-up video was using two of them to make a magnetic drill vice:
https://www.youtube.com/watch?v=orsmjiCMotM

...raw material if the OP wishes to custom-wind...

Need to build the DIY winding machine first
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shabaz 8 months ago in reply to beacon_dave

Novel way to make an electromagnet! : ) Very interesting video.

A few years back I was tasked with making one to pick up a little ball-bearing. I think (can't recall 100%, since I tried a few things at the time) I ended up pulling a relay apart and using its coil. Althiough I think electronics stores used to sell various general-purpose solenoids, I've not seen many/any recently. Maybe even take apart a door chime.

Nice for the OP to try things even if they are at a different scale to what's desired, to learn what impacts the ability to lift loads. Also there are hobby science stores (mindsetsonline, etc) who sell raw material if the OP wishes to custom-wind!
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beacon_dave 8 months ago in reply to M_G

Perhaps look closely at the individual weight of the materials you plan to use. It all adds up to the total.

You may also need to verify what it is that you are trying to attract with the electromagnet, how long you need to hold it for, and how the electromagnet itself is to be mounted.
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beacon_dave 8 months ago

Might be worth looking at salvaging a transformer from an old electrical appliance and turning it into an electromagnet.

This microwave oven one is too big and heavy but it may give you some ideas:
https://www.youtube.com/watch?v=DT0QHsN3vcE
Impressive result though.

Perhaps choose your batteries wisely as some will be able to deliver more current than others.

If it is more theoretical, then this may be of interest:
https://engineering.purdue.edu/~sudhoff/ee630/Lecture08.pdf
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dougw 8 months ago

Look up how much current your batteries can supply. Look up what is the smallest diameter wire that can carry that current. Based on the resistance of that wire calculate how much wire would it take for the resistance to be equal to the battery voltage divided by the current. Wind the maximum number of turns you can with that wire. Wind on a core that won't saturate. Calculate the inductance. Calculate the magnetic field. Calculate the force on the material you wish to attract.
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