I want to make power monitor by using CT only and I am directly providing the output of CT to arduino UNO on analog pin 1 without using any burden resistance but i am bit confuse about emon1.current(1, 11.1); and emon1.current(1, 111.1); what will be the effect of calibration i am getting perfect results by using emon1.current(1, 11.1); but i don't how it comes what are the effects of 111.1 and 11.1.
As I know my CT is 1000:1 so if i have load of 100 watts and our voltages are 220 so P=VI
then I=P/V ==> I=100/220 = 0.45
so by using emon1.current(1, 11.1); I am getting 0.47
and by using emon1.current(1, 111.1); I am Getting 4.7
Re: Help regarding emon1.current(1, 11.1); and emon1.current(1, 111.1);
If you have a CT with a current output (i.e. a pure CT with no internal burden resistor), then you MUST use an external burden resistor. That is because the current transformer is naturally a current source and you require a resistor to turn that current into a voltage that is suitable for the analogue input of your Arduino. Without a burden resistor, the CT will be overloaded and will not give the correct output - which is what you have found, and it may be damaged.
The way the calibration constant is calculated is clearly and fully explained in the Building Blocks section.
Re: Help regarding emon1.current(1, 11.1); and emon1.current(1, 111.1);
Thanks Robert.