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Apr19-08, 07:56 PM
P: 8
Thank you for the advice freinds,

I have now determined from what you told me and also some further research that i have built my coil correctly (except for the soft plastic part) I have replaced the coke lid makeshift washers at each end of the coil with Neoprene washers with far more durability. I have also scrapped running it from the pc power supply as 8 amps and also 20 amps seem to be too large to run through a single coil with no resistor. Also I am unsure of whether the output from the power supply is ripple current or AC, the labels on the power supply were half torn and all I have is that it is a 200W psu with 8 Amps on the +12v rail and 20 amps on the +5v rail, and as such I am going to opt for a large 12v battery instead like the kind in the bottom of electric lamps, look like a brick with two springs in top for terminals. 5cm x 5cm x 15cm approx.

However, I am a little stuck on my mathematical formula's and want to know from anyone who can tell me:

Is there an equivalency chart anywhere for Teslas, or Henries? What I mean is this, are there any guides that say 1kg of push power from the magnet = x amount of Tesla/Henries? I know the approximate weight I want to push with my electromagnet but I need to use this figure with the input voltage to calculate the turns in my coil. I hope that makes sense.


I have an input voltage of say 12v @ 2a (on a recharger circuit that keeps the 12v constantly at no lower than 75% charged) and it will run to a coil with 0.4mm SWG22 enameled copper wire of 200 turns. What is my push power in kg or grams?

For that fact does anyone have any links that will explain what parts of magnetism can be measured and what formulas to use. For istande in straight wire we can measure Resistance using Ohms Law, when using gravity, what can we measure and what formula do we use to measure it? Any links would be greatly appreciated.

Thanx again freinds..... :)