i need to built a low voltage current transformer 1:200, to sense current in my power supply. Please help me to get the simple, cheap method to do by myself. or there are standard CT that i can buy from shop.
TQ
Yes you can buy current transofmers. Take a look at Digi-Key for example Digi-Key
You can also design them yourself, if you want, just do a google search on "current transformer design" and you will get lots of hits.
Take a look at this **broken link removed**
Magnetics Corporation (makers of magnetic toroids and other materials) offers free software to design current transformers. You can download it here **broken link removed**