I want to have information about when our coffee machine is ready. This machine is open to common usage for about 20 people. I have a SCT-013-050 sensor and NodeMCU. My plan is simple, measure the current values and do the math. Figured the circuit without a burden like; https://learn.openenergymonitor.org/electricity-monitoring/ct-sensors/how-to-build-an-arduino-energy-monitor-measuring-current-only?redirected=true I have two questions.
First question: Do i need a burden? I have information about SCT-013-050 that says it has its own burden. So i figured calibration like below. Is it right?
Second question: I read some noisy values from sensor when it is connected to usb cable to computer and i see (near)zero value when i remove the sensor from the cable. But, when i power nodemcu from the power adapter (apple’s usb charge adapter) the value of sensor data dramatically increases and zero value is never seen. What should i do?