Guru
Joined: 02/02/2017
Location: AustraliaPosts: 1432
| Posted: 12:58am 23 Sep 2019 |
0W in bottom right corner is the product of DC volts and DC current.
IF there are available values for both, and they are sensible values,
then we get a DC current value visible and a DC power value.
Offset settings are needed due to many and varied methods we can use to
feed the nanoverter it's inputs.
The analog to digital conversion requires a voltage from 0 to 5V.
I like to use LEM closed circuit control Hall effect current sensors
for DC current. These are totally isolated, need 5V supply and give output
of 0V for -50A, 2.5V for 0A and 5V for 50A
I expect the zero amp sensor output to be close to 2.5V but never exactly
what the nano sees as 2.5V
So I need to obtain zero offsets for both current sensor inputs.
I have offsets for both NTC thermistors, so I can have them both showing the same
temperature when they are exposed to the same temperature.
I could not leave it be when I saw 5 degC difference between two thermistors which
were seeing the same temperatures.
The latest code for nano2 has a display of output AC amps and AC VA
I label it as "W" but again, it's the product of AC volts and current.
It is ignorant of power factor.
latest code (AC power display):
nano2_5_ac_current_sensor_dc_signal.ino.zip
wronger than a phone book full of wrong phone numbers