Okay, here the grand finale.
An oscilloscope is not the best tool the measure phase. But here is the best setup using it
1. Measure current with a non inductive resistor (test the phase of it on an LCR meter!)
2. Measure total voltage and current using the same model voltage probe. This will...
I measured the phase vs. frequency for the current probe before the voltage probe.
https://www.physicsforums.com/file:///C:\Users\Husain\AppData\Local\Temp\msohtmlclip1\01\clip_image001.jpg
The curves going from down to up, go in decreasing resistance values (all noninductive precision...
I tried a differential voltage probe, it did not fix the problem. I know that my problem is not delay because the delay times vary with frequency. The phase error has a strong dependence on both the impedance of the DUT and the frequency. Also, the error is way beyond reasonable delay...
I have a Tektronix current probe TCP305A w/ TCPA300 amplifier and a standard 10x voltage probe. After speaking with a friend about proper grounding practices, I was able to keep my phase error between -0.5 and 0.5 degrees between 1kHz and 100kHz. On an impedance analyzer(extremely accurate)...
I am not measuring radio frequency, rather I am using 1kHz to 100kHz range. I measured the phase lag from the current probe and voltage probe at different frequencies and for a noninductive resistor and other tests for very low loss capacitors. I get phase lag in each case, and it is not...
Thank you for those notes. We know that the way a circuit is setup (shielding, ground paths etc), the phase measurement suffers quite a bit, but the amplitude is not affected near as much. I am having trouble measuring phase (to measure power) using a passive voltage probe.
In a simple...
Hi all,
I found online that most professional websites suggest using differential probes to calculate power, along with a current probe, for a DUT. What advantage does the diff probe give us for power calculation?
Thanks
Hi all,
I have a general question about material properties.
We know that the material property value depends on the input level. For example, the permittivity in a dielectric material changes depending on the applied electric field.
That being said, when we apply an alternating electric...
I figured out that the voltage probe used to measure current through a resistor is sucking significant power (5mW depending on the phase).
I have decided to use the current probe with a 10x wire wrap. However, I get a imposed high frequency(3times my signal freq) sine wave on my signal. How do...
Thanks for your comment. I am sure I have the anti-resonance and resonance.
Using the voltage monitor at resonance (low voltage), the signal get noisy, meaning random DC biases. Using AC coupling does not solve this. Using the oscilloscope averaging and AC coupling, we get a random DC bias...
Hi All,
I am measuring the impedance response of a piezoelectric component. It has a unique impedance response having a resonance portion (low impedance ~10-30ohmns) and large impedance (100k-200kohmns) within a 2kHz bandwidth. See the webpage for a figure showing the impedance behavior. The...
I think your understanding of piezoelectric is not accurate. Piezoelectric is caused by an alignment of spontaneous dipoles. Most crystals have not spontaneous dipoles. For example, if you squeeze rocksalt, the net dipole in the material is still zero. Check out wikipedia for getting a basic...
Okay. When an open circuit is introduced, it is like the edges of the pipe are clamped.
Since the water at both sides of the membrane are at equal pressure, the forces on the membrane cancel and the membrane does not move. When the pressure is made to fall on one of the sides, the membrane...