### yhdc SCT 30 sensor, which the correct value

I'm using a non Arduino AVR, I have no equipments with the maximum value of scale, to test my stc sensor, I am using a simulator, to simulating a sct013-000 I use ISIN current 70.7mA with one Borden resistance of 33 ohm, with the function EmonLib library,(but adapted to my avr), put ICAL = 60.6. I use 5V on my AVR, then altered 3300 to 5000, and it works,I can get 100A(rms) . tested with a digital oscilloscope and get a peak value of 4,85V and 2.5V DC(see attach)
but as also have a sct sensor 30Amp, in this case, I have 1 V in the range of 0-30A, I put iCal = 30, used a VSIN = 1V amplitude, but in this case the scale is reduced, do not get the proper amount of current, get about 21Amp ... I tested with oscilloscope( see attach ) and get a peak value of 3.5V and 2.5V dc, I am using a voltage divider with 2 resistances of 10K each, but without Borden resistance.
My question is - does 1V rms is? that is 1,41V peak to peak? or Ical value must be different from 30?

### Re: yhdc SCT 30 sensor, which the correct value

A 1 V rms sine wave has a peak value of 1.414 V, and a peak-peak value (obviously) of 2.828 V.

But if I am reading your screenshot correctly, you have almost exactly the correct scale. Your sine wave is exactly 4 divisions peak - peak, and the scale is 0.5 V/division, therefore 2 V peak - peak, which equates to 0.707 V rms. If 1 V rms scales to 30 A, then 0.707 V is 21.21 A which is very close to the reading on your simulation.

### Re: yhdc SCT 30 sensor, which the correct value

if I change the VSIN for 1,41 amplitude, it show me the 30Amp value...
conclusion SCT 30 have 1,41 peak a peak and 1v rms

thank you Robert,

### Re: yhdc SCT 30 sensor, which the correct value

In electrical engineering, the most useful way to measure an alternating voltage or current is to use the rms value, because it represents the same heating effect that a direct current or voltage of the same value would have in the same circumstances.

But I think you either do not understand your current transformer, or you are getting confused with your measurements.

Your YHDC-013-030 will give you 1 V rms out for 30 A rms in. It will give you 1 V peak amplitude out for 30 A peak amplitude in, and it will give you 1 V peak to peak amplitude out for 30 A peak to peak amplitude in. Exactly how you measure the wave makes no difference, provided that you do it the same way for both input and output.

### Re: yhdc SCT 30 sensor, which the correct value

sorry my english, maybe I'm not communicate well ...
I mean I only can get the 30Amp if put VSIN with 1,41V amplitude, if I put 1 V amplitude only will get 21 Amp. see attached

### Re: yhdc SCT 30 sensor, which the correct value

Yes, that is correct. "Amplitude" is the peak value of the wave. The wave is a sine wave, the formula is

y = A sin( 2πft ) where A = Amplitude.

For a sine wave, the ratio Amplitude / rms = √2 ≈ 1.414

That is why you need an input of 1.414 V Amplitude = 1 V rms to indicate 30 A rms.