I have a few of these emonDC development boards, and a far as i know they are restricted to about 60V across the inputs, I have noticed that they have on board line voltage divider resistors, and wondering how they are, or could be configured to allow double the voltage on the main inputs so as to get around 120v plus, that will be used to monitor a string of 3 in series solar panel come in at about 120V open circuit.
We figured this out over email didn’t we Ross?
You powered a monitor from an isolated 5V supply, and biased the unit’s gnd at half of the supply with a pair of 4k7 resistors… The voltage reading was therefore halved, and was doubled later on in emonCMS.
Providing an isolated supply and biasing the GND, I’ll have to give that a try.
Yes we did config this over the email, yes i did use 4k7 resistors to read double the voltage reading capacity, and has been running well since