Guyzz i have an app , where i'm going to measure 3 voltages on a solar charger.
1: SolarCell output voltage
2: Battery voltage
3: Output voltage
The charger makes sure the battery is within limits 11.6 .. 14.1v , but the "unloaded" solarcell can output 21v.
If i set up the AD range on a M8 (VCC = 5V) , to 0..15v , what do i do to protect the adc if i accidently disconnect the solarcell from the charger , and 21v comes out/in there.
I was planning on using a 3 resistor voltage divider using 100K 1% resistors.
This would make the current around 100uA.
If i put a 5v1 Zener from ADC to GND would that work .. I mean still allow adc to function , and make sure it would survive a 25..30v input ??
This is a nice little free tool http://www.miscel.dk/MiscEl/misc...