23-07-2025, 01:04 PM
(This post was last modified: 23-07-2025, 01:11 PM by Mike Watterson.)
Note that unless a pair of windings are bifilar to make a centre tap, that the same turns ratio (needed for true centre-tap) on a normal core results in different resistances, because one winding is on top of the other, and thus needs more wire for the same number of turns.
Also for audio, the actual inductance isn't the most important aspect, but that at the lowest frequency the core doesn't saturate. With too many turns you have issues with the self capacitance and too much inductance for the high end of the frequency response. The thickness and material of core laminations and air spacing etc affects linearity and saturation. A core with DC saturates more easily. In this respect the driver for a push-pull has more issues with DC than the output transformer, because if the o/p is wound correctly the DC magnetisation currents cancel and the core only needs to cope with AC.
Also for audio, the actual inductance isn't the most important aspect, but that at the lowest frequency the core doesn't saturate. With too many turns you have issues with the self capacitance and too much inductance for the high end of the frequency response. The thickness and material of core laminations and air spacing etc affects linearity and saturation. A core with DC saturates more easily. In this respect the driver for a push-pull has more issues with DC than the output transformer, because if the o/p is wound correctly the DC magnetisation currents cancel and the core only needs to cope with AC.
