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Hi all,
I'm making two solenoids whose inductance I
want to measure. The way I do it is connecting a
solenoid in series with a resistor and then feeding
this circuit with a pulse signal(i.e. 1-0, 1-0,etc.)......
The small one seems to give a neat decay curve with a time
constant of 2microsec. using a 100 Ohms resistor. Well that means
L=t*R =0.2 mH..Disregarding the increase on L due to the different
layers with increasing section, I expect a value of
muo(pemeabilty of vacuum=4*pi*e-7 Wb/A)
n (density of turns)
S (Section of the solenoid)
L=muo*n*S=muo*(300/11*1e+2)*(pi*1e-4)=8e-7 H !!
This is the first problem.Huge discrepancy, isn't it?
The second is that I cannot get a clean decay curve with
the second solenoid. It is usual to see damped-like oscillations
but here indeed I get a more abrupt oscillations intead of the
smooth ones. And this with any freq.(50-2k Hz range scanned.
Although most measurments were taken around 1K;may high-freq.
effects already be important?)
Any Idea of how coul I get a smoother decay?
Should I try to get L via phase-differences between the
current through R and L,rather than measuring decay time?