Appendix A: Potential Dividers; Circuit Diagram; Operation - FIGnition FUZE Hardware Reference Manual

Appendix A: Potential Dividers

Potential dividers are used all the time in electronic circuits to generate voltages different
from an input voltage. It initially seems strange that simple components like resistors could
'modify' voltages when they aren't batteries and don't generate anything so we usually end
up trusting the rules.
This section will help you understand why they work. We'll start with the circuit diagram
and the rules for potential dividers. Then we'll provide a feel for what they do and finally
we'll explore a model for why they work as they do along with a simulation (that's also on
the FIGnition FUZE web page).

Circuit Diagram

! Fig A1! Fig A2

Operation

Fig A1 shows a simple circuit with two resistors. It has V at the top and 0v at the bot-
input
tom. So, the voltage must drop across these resistors from V all the way to 0v.
input