I have been looking at the Open Source Energy Monitor project and wanted to do a similar sort of thing, however using a slightly different method.
I am planning to use the 0-100A CT from Seedstudio, which from what I can tell is Current/33mA. http://www.seeedstudio.com/depot/noninvasive-ac-current-sensor-100a-max-p-547.html?cPath=144_154 From what I have read, does this mean that at 100A input, the sensor will report 33mA current output?
So by putting a shunt resistor across the output, it will gives a voltage output which I can then read.
Where the Open Source project is going into the Arduino ADC, I am planning to put mine into a 12bit IC, which then talks to the Arduino over I2C. The IC is a MAX127ACNG+ by Maxim. http://datasheets.maxim-ic.com/en/ds/MAX127-MAX128B.pdf The 12bit ADC I have can take a range on inputs, you can effectively program the range in when you communicate to it over I2C – rather nice really. It can take 0-10V, +/-10V, 0-5V and +/-5V
So taking this into account, I would ideally like the CT to provide +/-10V output, or failing that 0-10V output.
What I am posting about is hopefully for someone to assist with helping me achieve that from the Seedstudio CT Model: SCT-013-000. This is one side of things I have never played with before and am wanting to learn about.
Do I have this correct:
At 100A, it will output 33mA? V=IR, so 10V = 33mA * R So 10/0.033 = 303ohm
So if I put a 300ohm resistor in for the shunt resistance, and attach one side to a 10V supply, does that mean I will get +/-10V output over the 0-100A range, due to this sensor outputting AC? Looking a this further, I am not 100% sure about this. Do I simply put this into a Non-Inverting Op Amp setup, to achieve a +/-10V output?
Forgive the ignorance, as mentioned, not something I have played with before.