Have you calibrated your current transformer with the 4.7 ohm burden?
Rather than write your own code, why not use the OpenEnergyMonitor library, which is extensively tested and known to work well?
AC power is usually measured using RMS voltage and current quantities. What does this mean? Is the "device" accurately calibrated?
i have tried with a device of 6,51 A
how ?
My problem with OpenEnergyMonitor library is that i don't know how to calculate ICAL, VCAL and PHCAL
Perhaps some more study of the library docs and the OpenEnergyMonitor tutorials will clear up your confusion.
If you intend to calibrate your sensors accurately, calibrated references are required.
I have gone through all the resources provided by OpenEnergyMonitor, but I couldn't find the formula they used to calculate the ICAL value. In their example, they directly used 111.1 without explaining the formula behind it.
Explained in Installation and Calibration — OpenEnergyMonitor 0.0.1 documentation
Or to put it in words, the current constant is the value of current you want to read when 1 V is produced across the burden resistor.
Which depends on the CT you have chosen.
Have fun!
when i calculate current constant with this formula : current constant = (100 ÷ 0.050) ÷ 18 = 111.11
For me i have a CT 50 : 1 and burden resistor of 4.7 ohm.
So current constant = (50 ÷ 1) ÷ 18 = 10.63
i get false values i expect approximately 6.21 A and i get
I 'm not concerned about the equipment; it seems like you didn’t fully understand my question. What is the load current you are trying to measure?
the load current of device i try to measure is about 6.21 A
Not sure why you chose that transformer but it was a bad choice for this application.
A transformer with a much higher turns ratio would have been bettor
So, not 1 Ohm as you claimed in previous posts.
It is not at all difficult to calibrate sensors. Adafruit has a great overview and tutorial.
I am required to use this specific transformer as it is a direct request from my clients
No i have changed it, thank you
Well according to the data sheet (power: 0.2VA), the burdon resistor should be 0.2 ohms. Any thing higher will result in larger errors, maybe damage the transformer.
how did you calculate the 0.2 ohms ?
Power = I² x R
R = Power / I²
Power = 0.2VA (from datasheet)
I = 1A (from datasheet)
R = 0.2 / 1
Okay, but can i find this resistor in amazon for example
Maybe
I've tried a resistor of 0.2 ohm but it gives very far values than expected