How to find RMS, and Peak Voltages of this signal?

• Engineering
• CricK0es
In summary, the speaker is seeking advice on how to extract RMS and Peak Voltage from a complex waveform. The signal can change over time, so the speaker wants to analyze each setting separately. They plan to use FFT and Parseval's theorem to obtain RMS and peak values, but are unsure about adapting to changes in the signal's period. They also mention using a Hilbert transform to estimate dynamic periods. The conversation ends with the speaker asking for clarification on how to process the ADC data to get the desired values.
CricK0es
Homework Statement
RMS and Peak voltages of time slice in dynamic periodic signal
Relevant Equations
Parseval Theorem?
Hi all!

I have a complex waveform, something like what I have attached, and I need to extract the RMS and Peak Voltage from this. However, this signal can and will change after a number of cycles on a certain setting. So, this means the period and duration of pulse can change and so can the RMS/Peak. Imagine the entire signal is saved and I can scroll through it and perform DSP at will, but I don't want an average over this. I want specific analysis of each setting.

After I have run the signal through my variable op-amp and ADC (they aren't a problem. Assume sample error find is +/- 0.5% // negligible), conceptually how would I obtain these things using a programmed FPGA? Essentially, how can I ensure I am making the correct time slice for analysis?

Currently, I am thinking about using FFT & parseval's theorm to obtain RMS from my signal slice, with peak just being a max{} search of the slice data. Therefore, I guess my main issue is ensuring that I am able to adapt to slice out the correct period as the signal changes it's period. In my research I have seen a lot of things about using a Hilbert transform and estimating changing/dynamic periods from envelope maxima. Is that along the correct lines?

Nonetheless, thank you for your help. Apologies if it is unclear as naturally it's hard to explain something for which you lack understanding.

Attachments

• VoltageCurrent Blend.png
34.5 KB · Views: 156
If you have the ADC data, you just process it to get the values you want, no? I guess I don't understand the subtleties of your signal changes and time windows...

BvU

1. What is RMS voltage and how is it different from peak voltage?

RMS (Root Mean Square) voltage is the measure of the effective or average voltage of an alternating current (AC) signal. It takes into account both the magnitude and duration of the voltage. Peak voltage, on the other hand, is the maximum voltage reached by the signal at any given time.

2. How do I calculate the RMS voltage of a signal?

To calculate the RMS voltage, you need to square the values of the signal at different time intervals, add them all together, divide by the number of intervals, and then take the square root of the result. This can be done using a mathematical formula or with the help of a digital multimeter.

3. Can I use a voltmeter to measure both RMS and peak voltages?

Yes, a digital multimeter can measure both RMS and peak voltages. However, it is important to make sure that the multimeter is set to the correct AC voltage range and that the signal being measured is within the range of the multimeter.

4. What factors can affect the accuracy of RMS and peak voltage measurements?

The accuracy of RMS and peak voltage measurements can be affected by factors such as the quality of the signal, the frequency of the signal, and the accuracy of the measuring instrument. Additionally, any external interference or noise in the circuit can also affect the accuracy of the measurements.

5. Can I use the RMS voltage as a measure of the signal's power?

No, RMS voltage is not a direct measure of the power of a signal. It is only a measure of the effective voltage. To calculate the power of a signal, you would need to multiply the RMS voltage by the current in the circuit. Alternatively, you can also use the peak voltage to calculate the power of the signal.

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