Ok, First of all, this is my first post, i hope you will forgive me if this has already been done but i searched electromagnet and there were far too many results that were nowhere near relevant to building them.
Now that that is out of the way here is what i have to do.
I have been challenged to build an electro magnet and to obtain the best mass of device:mass lifted ratio. So please note THIS IS ABOUT EFFICIENCY NOT TOTAL AMOUNT LIFTED.
Specs:
The electromagnet and weight (not sure about the battery and holder) may not exceed a diameter of 100mm (5 cm radius if that helps) and may not exceed a length of 50 cm.
the entire device including weight may not exceed 5kg.
No permanent magnets are allowed anywhere in the weight or device (except the inevitable remnant magnetization)
must be powered exclusively by AAA, AA, C, or D size non-rechargeable batteries (no car batteries). they must be alkaline flashlight batteries and lithium, nickel-cadmium or nickel-metal-hydride may not be used, from any source. TOTAL VOLTAGE MAY NOT EXCEED 30 Volts.
also, no part may exceed a temperature of 50C during or after the 10 second run.
MY thoughts/ questions.
I know that the electromagnet would work best with the most current pumping through it, would anybody recommend the best combination of batteries? (i.e. 20 1.5V batteries in series, with some amount in parallel to increase amperage)
Also, I know the core would perform best if bent into a U shape.
As for the Core metal itself. Would you recommend a simple soft iron? or maybe a bar of Neodymium that was heated past the curie point (it's fairly cheap nowadays) ? what would you recommend?
obviously i want the thing to be efficient so what would be the best wire to use (it will have to be able to carry the current without heating over 50C)
That is my challenge. Does anyone have any input? ANYTHING would be appreciated.
Thanks,
Gmano