I try to make a 110VAC energy meter connected to my computer out of the CS5490
This IC measures voltage and current over a voltage divider and shunt resistor respectively and then calculates the power. Besides connecting the measure inputs, the IC also needs power. In a stand alone metering application this power needs to come from the same line and that is the example they give in the datasheet. But in my case I have an external power supply that I would like to use. Also I think (correct me if I am wrong) one should not connect the Neutral from the line to the ground from a PC.
Fig 21 on page 54 of the datasheet is then plain wrong?
What is the correct way of doing this? Can I do it without the need of adding another power supply? And what does a pointing down triangle mean compared to the more usual ground symbol?
It's an awesome group of EE's here, any help is highly appreciated!