Hey everyone
i need to convert ( 0v-->90V) to (0v ---> 5V) so i can use it in my Micro-controller , i tought about using tension devider but i don't think its a good idea because of joule heating
can you please help me with this ?
Does your microcontroller input have an internal resistance greater than, say 50k?
If so then you can make a resistor divider with high enough values that they will not heat up much. The main dropping resistor can be a common 1/2 watt size.
Your microcontroller input ought not load the divider so much as to affect the reading by more than a few percent.