Recent content by sparks_nz

Thanks for this. I will sweep the trifilar winding with a freq gen to see if there are other resonances. I have only been focussed on the fundemental.

Thanks, It confirms what I am thinking. I wonder if this trend would just continue if the number of filar windings were increased incrementally in separately made coils (say 3 up to 10), while keeping the same number of total turns constant?

Thanks for your reply on this. Can you elaborate please on the coil's self resonant frequency in regards the difference between the trifilar coil and single wound coil of same number of total turns? I presume the trifilar will have a much lower self resonant frequency and Q?

The parallel cap was just to test the variation in freq to roughly ascertain what sort of Q the inductor had when already resonant with its internal capacitance. I am interested in experimenting with producing an amplitude modulated sinewave envelope using pwm. No particular dedicated project...

Thanks for the advice, Its appreciated. The use of 32kHz is due to the generator I am using. I will look up the suggested materials.

Thank you all for your help. I am experimenting with PWM and using the coil / transformer driven by dc pwm switched source. To answer your questions: The carrier freq is 32kHz. Yes the primary is approx 50uH. The added cap of 50pF does not dominate the self capacitance of the coil. The wire is...

I don't have a toroid winding machine. The trifilar wire is made manually by measuring out 3 equal lengths of wire, and then twisting them together. I use an electric drill for that. The effort is in holding the toroid and wire and doing the manual threading process. As can be imagined, 39 turns...

Its basically a tuned circuit, but with a 2 turn primary to energise it. Are you saying the 39T trifilar wind would have higher Q than 117T?

Im sorry I didnt explain the matter more clearly, but the crux of it is that to wind only 39 turns of x3 is much easier than winding 117T on the toroid.

Thanks, I saw the error just after posting it.

Hi, its 3 wires twisted together and wound as a single wire would be. The 3 coils therein are connected in series to form an inductor that effectivly is 3 times the amount of turns the original winding.

Hi, I am experimenting with a design for an inductor for audio applications, and am using a high permiability toroid (12,000) having a closed trifilar winding. In this instance , it is 39T x 3 twisted wires connected in series being 117 turns in total, giving approx 180mH inductance. In...