Hi, I need to measure current with a sct 013-000 that have 0-50mA output at their maximum Amp reading (100 amps), I read a LOT of alternative ways to do it, can I just use a 100 Ohms resistor to get a voltage from 0 to 5 volts (Analog read)? Using Ohm's law, if I have 100Amps AC, my SCT will drop me 0.05 A, and with a 100 Ohms resistor it will me a 5 V reading, is this true?
Regards.
That is all correct as far as I can see.
Did you not read this?:
https://learn.openenergymonitor.org/electricity-monitoring/ct-sensors/interface-with-arduino
That's a clamp-on type indeed.
Now what do you want to read, really? Just the average current or the complete waveform?
The waveform can be done as described in the link of #2.
The average is easier from an Arduino pov as a single reading of the analog input gives the answer. On the hardware side, other than the burden resistor you need a diode (half wave rectifier - for high accuracy use an OpAmp in ideal diode configuration) and peak detection circuit (a resistor and a capacitor in parallel).
Also you should aim at bringing the output voltage to <1.1V so you can read it against the internal reference, instead of against Vcc. You think Vcc is 5V but often enough it's not. Or it's unstable. The internal reference is stable, though you have to calibrate its actual value (it's nominal 1.1V but with a 10% tolerance)
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