how to measure U,I,cos pi ?

[conchoxu]

I want to make a circuit using mcu (microcontroller) that's can auto measure U,I, cos pi on the load AC (220v). It's same Watt meter hour . Please tell me some suggestion.
Thanks.

 

[DTaylor]

Aldi are now selling plug in meters for 7 quid that do all that and more.

Just out of interest what is it for? cost calculation?

 

[conchoxu]

thanks . But this is project I can't buy a production that can do at all.
Because this project is studying.

- I think. If I use some resistors that's parallel with load (ac) then I use a rectifier to conver ac to dc and put into ADC of microcontroller. So I can measure Volt of the Load.
- With current ac, I use a sense resistor (1 Ohm). I solve it same about.
the Ohm law (I = U/R). I measure the current.
- But how a bout cos (pi) , and total power on the Load ?
All that's measured will be translated into Master (computer) on the RS485 network.
- I have some picture that's suggest a little but I am not sure.
Please tell me your point about It . thanks