Digital to analog conversion

Hi , 

I am interfacing the CT sensor and arduino to the matlab and would like to get the original signal obtained from a CT sensor in the Matlab. Can anyone guide me on the steps to be performed initially for the digital to analog conversion and getting back the original signal in Matlab. 

 

Thank you for your guidance. :) 

Robert Wall's picture

Re: Digital to analog conversion

That is going to be difficult without knowing exactly what you want to do with it once you have it. The standard sketch gathers around 2500 sample pairs (voltage and current) per second, sampling current only would approximately double that. But you then have the problem of getting the numbers out to do anything with them. If you want only one cycle or so, what I've done in the past is store the data in an array and read it back at leisure (i.e. not real time). Or you could go down the route I used for the pictures in the report on the ct, which is feed it into a PC sound card and capture the data from that - you can then easily have 48k samples per second, and that completely bypasses the Atmega 328.

hmaggo92's picture

Re: Digital to analog conversion

I just want to perform the FFT analysis of the original current signal after obtaining the signal after D/A processing in Matlab. I have successfully tried reading and storing the data in an array in Matlab for two cycles, and those are sufficient for me.

Any suggestion on how to obtain the signal approximate to the original current signal in Matlab ?

sunnyflad's picture

Re: Digital to analog conversion

...connect the current transformer output to the audio input of a PC, and capture a WAV file (open source Audacity is very good for this- can even do a basic FFT if you wanted)

sunnyflad's picture

Re: Digital to analog conversion

off and you can use more highPlug the CT into  power kit why not  plug the Current TX into a PC and use open source Audacity to record as much as you like as "audio"? Audacity can do a simple FFTplesor easy to export from there as .wav samples

Robert Wall's picture

Re: Digital to analog conversion

Isn't that almost exactly what I suggested above? Try reading the report on the YHDC ct for details of how to do it. The phase angle measurements came out of a spreadsheet doing the DFT calculations, the original data was captured as explained in the report.

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