Vrms readings by using analogRead function

Projects Programming
38

1. The OP uses 230V/6V Transformer and full wave rectifier. You (@RayLivingston) added filter capacitor.

2. So,
Vdc = 2Vm/3.14
==> Vdc = 21.41*6/3.14 = 5.38 V

3. So, according to above quote --
Vrms = 5.38*0.707 = 3.80 V

But, the Vrms of the line voltage is: 230V.

4. I would say that you need a calibration factor (the gain factor) in Step-3 to get 230V.
Vrms = 3.80* G
==> Vrms = 3.80230/3.80
==> 3.8060.52

5. The codes are similar to post #12.

void setup()
{
  Serial.begin(9600);
}

void loop()
{
  float vrms = (5 * analogRead(A1)) / 1023 * 60.52; //
  Serial.println((byte)vrms);
  delay(1000);
}