Practical Coilgun Design 

Theory

Wire SizeHow do you choose the wire diameter? Suppose you know the desired coil dimensions and want to achieve a certain coil resistance by filling that volume with wire. Find Resistance, Given Coil Dimensions and WireLet's start with the basic equation for d.c. resistance of a coil: R = (4 D T ω) / d^2 Substitute turns T = L l / d: R = (4 D L l ω) / d^3
Find Wire Diameter, Given Coil Dimensions and ResistanceSolve the above equation for d, wire diameter: d = cube root( 4 D L l ω / R ) Note result goes as the cube of the wire diameter which makes diameter tolerance important. 



Last Update 20140627
©19982021 Barry Hansen 