Continue to Site

Welcome to

Welcome to our site! is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

can Micro Controller mesure AC 220V current ??

Not open for further replies.


Member level 5
Sep 20, 2002
Reaction score
Trophy points
Activity points
I want to make AC 220 current and voltage meter.. How do I make it..?
what the easiest way to mesure AC 220 current with micro controller ?? I have try for lower voltage DC i could used shunt and ADC on AVR Micro but what about 220V AC?? Any idea?? please.


Yes, is possible... you must use a current transfomer for current measurement, and a voltage transformer for voltage measurement.

With this devices you will have galvanic isolation between the AC network and your processor.

Best regards;

the easiest way to measure AC 220 current is to use a current transformer.

Here's an application note about interfacing a current tranformer to an ADC: **broken link removed**

Current transformers from CR Magnetics: **broken link removed**

Btw. the european countries has changed the line voltage from 220 VAC to 230 VAC an U.K has changed the line voltage from 240 VAC to 230 VAC.

Thanks.. but i wonder if there such a small current let say about 0.5-5 A is it work good with this method? because very small current can produce very small amount of voltage from current transformer.. did any one try this methode for small current ?


I think this Application Notes, from TI, will help you.

**broken link removed**

**broken link removed**

**broken link removed**

Best regards

I would recommend you use one of these true RMS current transducers with 0-5 Vdc output, they have a basic accuracy of 0.5%. **broken link removed**
You can get these transducers with current ranges from 0-0.5A, 0-5A, 0-10A and so on. So it should be possible to find a transducer with the right current range for your purpose. If you choose one with 0-5Vdc output you can connect it directly to your ADC. It doesn't get easier than this.

You can also find true RMS AC voltage tansducers, AC power transducers and frecuency transducers at this site as well.

Data sheet for true RMS AC current transducers: **broken link removed**

Data sheet for AC current transducers:
**broken link removed**

Application note for AC current transducers:
**broken link removed**

Not open for further replies.

Part and Inventory Search

Welcome to