I am planning to do a current measurement with Arduino. The board I'm using is mega 2650, operating voltage is 5V (I/O pin limit is 3.3V). And the CT I'm using is exactly the same as this tutorial, the only difference is that the output of the CT is limited to 0-1Vac.
Now, I'm thinking if it is possible to directly connect the CT to the Arduino board? What would be the outcome if I connect a AC voltage source to it?
Moreover, if direct connection is not possible, then a simple bridge diode could turn AC to DC. But again, a ripple signal will be resulted and with a measuring current of 0-100A ac and output signal of 0-1Vac ( meaning 1A ac measured current only result in 0.01Vac). What would be the resulted accuracy? Best if could archive measuring accuracy to +-0.1Aac.
Best Answer
You can do something like this. The 1VAC signal will then be between 2 an 3v so the arduino wont have a problem reading it in.
edit: The resistor should be around 1k - 10k
simulate this circuit – Schematic created using CircuitLab