Measure current from main supply...

[armghan11]

1) I want to measure current passing through main supply 220V AC 50HZ and fed it to the ADC of micro controller... what type of rectifier and filtering circuit should i use ? i am working on non intrusive load monitoring system... which identify loads on the basis of current signal.

Note:I don't want to use step down transformer

2) I am attaching one circuit suggest to me by someone... the 0.22ohm is a shunt resistance attached with neutral line of supply to measure current...
if i use the circuit given in figure.. what adc calculation i need to get current.

 

[srjth.m1]

you can use some optocoupler's,that one is more safer i think,that makes the circuit very simple

 

[asimlink]

i would suggest read following topic that describes methods used for ac current sensing
**broken link removed**

I personally like use of Current transforer (called CT) for sensing AC currents.

Please see how a CT looks like:
https://www.sparkfun.com/products/10341

 

[armghan11]

you can use some optocoupler's,that one is more safer i think,that makes the circuit very simple

i would suggest read following topic that describes methods used for ac current sensing
**broken link removed**

I personally like use of Current transforer (called CT) for sensing AC currents.

Please see how a CT looks like:
https://www.sparkfun.com/products/10341

what about the circuit i attached with my post ? is it ok? because i am in Pakistan and linear octocuplers are not available in market .... i have to use some standard components

 

[armghan11]

Waiting for replyyyyyyyyyyy

 

[srjth.m1]

i didn't getting how you are giving directly to diode from supply,i don't think so you have to use some transformer or optocoupler to reduce the voltage.pls specify every components you used when you making a circuit diagram

 

[asimlink]

In pakistan you can find parts from some online suppliers:
one of them is https://www.evselectro.com/

At evselectro you may find current sensing parts such as:
1. Current Transformer CT:
https://www.evselectro.com/lem-la55...r-la-55-p-4154?keyword=current &category_id=0

2. DC Current measurement:
https://www.evselectro.com/kits-30a...or-module-3024?keyword=current &category_id=0

3. Hall effect DC current measurement:
https://www.evselectro.com/index.ph...eyword=current+&category_id=0&product_id=4631

hope this helps!

 

[eiphan]

I want to suggest to use Hall effect current transducer, it has isolation and better accuracy. However, for AC current, CT is also a good choice since it is cheaper and provide isolation. All the best!