gistfile1.txt

The YHDC SCT-013-000 CT has a current range of 0 to 100 A. For this example, let's choose 100 A as our maximum current.

Primary peak-current = RMS current × √2 = 100 A × 1.414 = 141.4A

The YHDC SCT-013-000 CT has 2000 turns, so the secondary peak current will be:

Secondary peak-current = Primary peak-current / no. of turns = 141.4 A / 2000 = 0.0707A

If you're using an Arduino running at 5V: AREF / 2 will be 2.5 Volts. So the ideal burden resistance will be:
#NO: Ideal burden resistance = (AREF/2) / Secondary peak-current = 2.5 V / 0.0707 A = 35.4 Ω

### But, I have 3.3V Particle Photon!
Ideal burden resistance = (AREF/2) / Secondary peak-current = 1.6 V / 0.0707 A = 22.6 Ω