Good day, i have project to measure small current below 1 amps and then monitor it through website. Im planning to use thingspeak. Im using sct013 5A/1V and the module to convert the outout from 1V Ac to 2.8DC, i bought it from df robot. And using ads1115 for external adc bcs esp32 isnot quite good.
But i have problems with the measurement. When i plug my sct013 to the cable with no load, it reads 50-58 adc value. And i cant get detail current measurement. Im using 3.3v for the module of esp32 and ads1115 Vin
I wonder, bcs im using the module for sct013, does it mean now my output is 2.8dc max rather than 1VAC ?
And when i set the gain in the ads1115, does that mean my vref is set as my gain ?
Welcome, @Bagus_sss to the OEM Forum.
Which module is this? It reads as if it is a full-wave rectifier and smoothing to give you the peak to peak value of the current transformer output.
With a 3.3 V supply, 50 counts from the ADC represents 50/65535×3.3 V ≈ 2.5 mV, this is only 0.076% of the full scale reading of nearly 5.9 A. If this is the peak to peak value from a 5 A current transformer, it means you are recording a rms current (IF is is a pure sine wave shape) of ≈ 4.5 mA.
I think it is likely this is electrical noise picked up either from your 3.3 V power supply or by the c.t. cable working as an aerial, and the rectifier is making it worse because it responds to peak values.
I think you must screen your circuit, filter the 3.3 V supply, and maybe filter the c.t. input.
Also to try to remove any noise coming in to your circuit.