Hello Nico,

Usually to measure AC current you would use a current transformer (CT). There are two type of current transformers. first type is shaped like a doughnut and the current carrying wire is inserted thru it. Second type is shaped like a C type vice device which you open the jaws and put around the current carrying wire.

You will need to convert the output of the current transformer to a voltage level which is usually done with a transducer which converts current into voltage suitable for measuring. Typically 0-5 VDC output for proportional current input.

All of the above devices are expensive and difficult to work with and require special skills to install.

One special precaution in dealing with Current Transformers is never to open their circuit while current is flowing threw the current carring wire. This will create a large voltage which can harm you.


I have in the past modified simple Volt meters and Amp meters which would give a 5 VDC output proportional to input and feed that signal into a National ADC 12138 integrated circuit and used a 89C2051 to read the results.

The results were uploaded via a modem to an Internet web site and the user could view three variables (Temperature, Current and Voltage) on a simple line graph so that they could see what their equipment was doing.

Good luck with your project.

Regards,

Charles Bannister