have a number of 12 and 24 volt batteries whose voltage i must monitor.
am using raspberry picoW boards for this, they have 2 (or 3) ADC inputs that can read 0 - 3.3 volts.
according to what i am reading the way to do this is to make a voltage divider, usually from resistors.
according to my (very rusty) education, this voltage divider draws current at the rate I = V/R.
as far as i can tell this wastes power, which defeats the point of my project.
i need a way to disconnect the voltage divider when the board is not using it.
i could use a relay, but this seems a waste.
would it be possible to disconnect the voltage sensor using a transistor, perhaps?
if so, could anyone advise me how to wire this, without blowing up my boards?
am using raspberry picoW boards for this, they have 2 (or 3) ADC inputs that can read 0 - 3.3 volts.
according to what i am reading the way to do this is to make a voltage divider, usually from resistors.
according to my (very rusty) education, this voltage divider draws current at the rate I = V/R.
as far as i can tell this wastes power, which defeats the point of my project.
i need a way to disconnect the voltage divider when the board is not using it.
i could use a relay, but this seems a waste.
would it be possible to disconnect the voltage sensor using a transistor, perhaps?
if so, could anyone advise me how to wire this, without blowing up my boards?