Hello, Sorry for me English . I use sensor type SCT-013-030, and my problem is ,that even the disconnected sensor measure value in arduino (0.6 - 0.7) Irms , resistance 37 ohms, Calibration is 29. Is it OK?
Many thanks,
Peter
problem SCT-013-030
Submitted by Guest on Fri, 11/10/2013 - 12:10»
Re: problem SCT-013-030
37 Ω is the resistance of the SCT-013-030 when you measure it? This is probably correct.
It is normal for digital noise from the digital part of the Atmel processor to get into the analogue to digital converter and you read this as a current even when no current is flowing. When you disconnect the c.t, the input of the analogue to digital converter is open circuit (you should not have a 33 Ω external burden resistor) and the input is more likely to pick up more noise. However, the "current" that you report does seem more than usual.
Does it read less when you connect the c.t. but it is not clipped on a cable?