I have tried to measure the phase between the source voltage (a sine voltage) to the voltage on the capacitor and resistor.
by my understanding the phase between the source and the resistor is
arctg(1/(wRC)) (which i actually received)
and between the source and the capacitor the phase is
arctg(1/(wRC))-pi/2
but this result I dont receive. I get something different that when w->infinity the phase goes to zero
can someone first approve my understanding of the theory and try to explain it?
I mean the phase shift between the entering voltage (the source) to the received voltage on the resistor or the capacitor
for the resistor I get good results
phase=arctg(1/(wRC))
but not for the capacitor which in my understanding should be
phase=arctg(1/(wRC))-pi/2
it's not so hard because the scope generates a file that can be used in matlab to get the result.
the circuit is connected correctly if this is your question.
this is the graph I receive **broken link removed**
it's close to the expected one except the part that raises back up.. I think it should keep go down to -pi/2
Try this. Duplicate your circuit by a magnitude of say ten. Then measure phase. I still question the scopes ability to distinguish small phase changes. At minimum, have you checked scopes specification for phase measurement?
If that's a low pass RC filter than you expect the wrong thing.
The phase is -atan(w*R*C), not what you are showing.
Check my circuit drawing above and tell us if that is the circuit,
or else draw the circuit yourself so we know.
With the scope ground connected to the signal generator ground and
the scope probe connected to the junction of the resistor and
capacitor (this will be looking across the capacitor) you will see the
phase as -atan(wRC). This is the normal way to look at the output
of a low pass filter anyway.
If you would like to post your resistor value (ohms) and capacitor
value (farads or microfarads) and choose some frequency f and
tell us that too and we can calculate the phase and then you can
compare to your own readings.