Another way would be to derive the current by the number of turns of the coil. Deriving the current by the resistance is not possible you guys say? due to the AC current. I have a spare motherboar with the same coil that i can unsolder. I can use it to measure the characteristics if needed.
But I thought you were talking about DC current?
Deriving the DC current is easy: you need to know the resistance and voltage and use Ohm's law.
Calculating the AC current is also not difficult but you need to know the inductance too.
The only option I have is to use a Hall Effect sensor I think, but thats my last solution because i have to place it inside a computer. THere is a great chance that interference will occur.
A Hall effect sensor will work but for AC it'll need to work up to the frequency being measured.
But why do it the hard way? It's DC so measure the resistance of the coil, the voltage across it and calculate the current.