Are you a differential equations god or do you just have the biggest reference manual on earth?
Hi again,
Not sure what you mean here. I am using circuit analysis which may or may not need differential equations. There's also Laplace Transforms which helps a lot for these smaller tasks. This involves solving the circuit for whatever variables you think you can measure and then simplifying as much as possible to get the solution you want.
I was editing my previous post adding stuff you probably didnt see before you replied so i'll repeat the sine wave test part here. It's not that hard to comprehend so you dont need a full reference i dont think.
When using a sine wave, the amplitude of the current is:
Ampl=(E/R)/sqrt(w^2*R^2*C^2+1)
and the phase shift:
TH=atan(w*C*R)
where TH is the angle beween current and voltage.
From the amplitude we get:
C=sqrt(Ampl^2*R^2-E^2)/(w*E*R)
where
E is the input sine amplitude (volts peak or rms volts),
Ampl is the current response sine amplitude (same peak or rms as E except amps),
R is the load resistance in ohms,
w=2*pi*f,
f is the frequency in Hertz
It's also a little interesting that the resistance is:
Rx=E/(Ampl*abs(cos(TH)))
However, if the input surge during startup is a major concern then it should be tested at turn on not during normal operation.