AC vs DC to arduino pins

Forum 2005-2010 (read only) Hardware Interfacing
#1

Total newbie question. Just got my Arduino in the mail and am teaching myself electronics. My first project will be a sort of power meter and so I am wondering if the output from my coil transformer (AC) can be sent to one of the Arduino analog I/O pins, or if I need to change it to DC first?

I can only assume this sort of question has been asked by many newbies be fore me, so if there is a standard place you could send me to to find the answer, that would be great!

Thanks Ray

#2

You can't connect voltages to the Arduino that go outside the power rails of the device, this is a almost universal rule for semiconductors.

It can be AC but only if it is within the 0 to 5V range. Most AC will go negative and damage your Arduino. Therefore best to turn it into DC. Although sound waves are AC and can be connected like this:_ http://interface.khm.de/index.php/labor/experimente/arduino-realtime-audio-processing/

#3