Original poster: "Gerry Reynolds" <gerryreynolds@xxxxxxxxxxxxx> Hi DC,I've been thinking that the relationship of inductance to number of turns squared has a lot of error in it for tall skinny coils. I believe the equation of:
L = uo*N^2*Area / lengthassumes that the coupling from each turn on the solenoid is 100% into all the other turns so that the total flux thru any one turn is proportional to the number of turns. For a very short and very fat coil, I believe this relationship would be close. For TC secondaries with H/D ratio of say 5:1, there is a lot of error in the number_of_turns squared relationship. I bet the real exponent is between 1 and 2 for typical TC geometries. I might try to plot this using JavaTC and see if there is an effective exponent given H/D.
Gerry R.
Original poster: "resonance" <resonance@xxxxxxxxxxxx>Also, inductance varies as the square of the number of turns, so you want a lot of turns on the sec.