I have been searching like a maniac for as much info as possible before placing question here, obviously i failed...
The question is about voltage divider, i have an external source that gives me either 12-13V or 10-11V, now looking at voltage divider, if one would be implemented for this signal cable i should be getting out between 2-4V (max that i need is 5V so im gonna try stay below 5 for safety).
Looking at this picture, i saw somewhere if
- Vin = 12V
- R1 = 100K
- R2 = 10K
then i should get Vout at somewhere "around" 5V... now i tried that theory in practice, my supply is dynamic so i can change the Vin to 10, 12 or 15V or what ever, but the voltage never decreased more than 1-2V.
I also tried to chain up with more resistors, like multiple 1M, also with multiple 100K and 47K but the voltage never decreased and pleasurable amount to hook it into Arduino digital pins.
I have a hobby project that i want to finish up before saturday but this "issue" drives me crazy as im not even close to 5V.
Also worth to mention i was suggested to use a comparator (couldnt tho find any comparator that had pull-down output in my local store) but then later on some said a comparator would be "overkill" for my tiny project since i only need to compare this either 10V or 12V in arduino, where divider would be more suitable.