mesure AC current using shunt!

[jouyorin]

Hi i want to mesure ac current (0amp to 30amp) in asynchrone machine (300v) , using shunt resistance..but i don't know if this circuit is correct and how to mesure exactely the others resistances ! can any one help me please!!

 

[mjasoj]

I can understand your question nicely because i have faced the same problem a couple of weeks ago. Would you please clarify on which device you are going to measure the current?
You need Current to ADC Value Converter? or Some other thing?
Or you want to convert Current Reading to some Voltage Value?

 

[jouyorin]

yes i will use it with arduino so i need 5v in output..

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i hope you can help me please mjasoj !

 

[schmitt trigger]

With a voltage of 300v above ground why don't you better use an isolated solution like an ACS712?