Current detection of ferrite core
I am making a circuit for overcurrent protection where the circuit is shut off using a relay if current is greater than 10A. For current sensing, I chose to use a current transformer.
My question is that, if I'm measuring the current flowing through at 220VAC 50Hz, can I use a ferrite toroid? I was thinking of 1 turn and 100 turns. Will this work? Will there be a problem if I use ferrite at this low frequency?
Yes, you can use it but you will need to use an amplifier in order to increase the voltage.
Anyway, I recommend you to use a select hall effect sensor even though is more expensive.
Some ferrites will work depending on the one you choose. Make ensure it has enough magnetizing inductance on the secondary to not load down the burden resistor and not saturate the secondary.
Also, for low frequencies laminated steel is generally a more convenient choice.