STEORN DEMO LIVE & STREAM in Dublin, December 15th, 10 AM

[gyulasun]

Hi Omnibus,

your coil data gives 71.6uH inductance.

OD=46mm
length=17mm
N=36 turns

I used this link but several other similar online single layer air core calculators give the same 71.5-71.6uH inductance.

http://www.captain.at/electronics/coils/

Gyula

EDIT: I used a wire diameter of 0.472mm.

[Omnibus]

That's correct, and therefore the inductance can practically be ignored. Now, all the problem stems from my lacking of a current probe which is more expensive than the scope itself. I tried measuring the current by adding a resistor in series with the coil in question and measuring the voltage drop across it to divide by its resistance. The voltage in this case is measured across the coil and the resistance in series. However, if you do the measurement in this way you add active resistance to the active resistance of the coil and this is something you don't want to do because that changes the circuit and that new circuit may not be giving the effect.

Also, the formula for calculating the inductance value isn't a function of frequency so it seems there shouldn't be any concern regarding frequency effect on inductance.

[Omnibus]

Now, watch this. This is with active resistance as load only:

[Omnibus]

And the corresponding Excel data.

Seems we're getting beyond the limits here with these microjoules.

[X00013]

http://www.youtube.com/watch?v=Wu1tiMXqNEc