What a great website! I have not been doing much work with electronics for many years (wife, kids, job etc) but now I have a little project that I would appreciate some help with - if anyone has time!
I want to measure the current drawn by a 240v AC device where the range could be between 30mA and 13Amps, or even zero (device switched off).
Somehow, perhaps with a resistor, I need to turn the current into a voltage between 0 and say 5volts so that an A/D converter can sample the voltage.
I have tried playing around with current transformers but the output voltage is either too small or too large. And to make things harder the CT picks up so musch noise that detecting small current changes is almost impossible!!
Where do I go from here? Is the primary current range too big or is there another way of measuring current that doesn't involve a CT?
I would relaly appreciate any suggestions before I go bonkers!
thanks in advance.
Terry
I want to measure the current drawn by a 240v AC device where the range could be between 30mA and 13Amps, or even zero (device switched off).
Somehow, perhaps with a resistor, I need to turn the current into a voltage between 0 and say 5volts so that an A/D converter can sample the voltage.
I have tried playing around with current transformers but the output voltage is either too small or too large. And to make things harder the CT picks up so musch noise that detecting small current changes is almost impossible!!
Where do I go from here? Is the primary current range too big or is there another way of measuring current that doesn't involve a CT?
I would relaly appreciate any suggestions before I go bonkers!
thanks in advance.
Terry