I am designing a circuit but I am facing a repetitive design that require too many resistors. The problem comes down to answering if the next two circuits are equivalent in terms of voltage drops:
simulate this circuit – Schematic created using CircuitLab
Note that there are actually n resistors: R2,R3,…Rn. All values are known and can be different from each other(R2<>R3<>R4<>…<>Rn) and R1,R2,..Rn have the same values in both scenarios (the values on the drawing are incorrect).
The question is as it folows: Is the voltage drop on R2,R3,…,Rn same in both scenarios?
Best Answer
Clearly not!
Consider if R2 is 0 ohms, then in the op circuit there is NO VOLTAGE developed across any of R2-Rn because they are all short circuited by the 0 ohm R2. Clearly further in the first circuit the voltage is the SAME across all resistors R2-Rn because they are in parallel.
In the second case you have a number of individual potential dividers, so having a zero ohm resistor for R2 only means the voltage drop across R2 is zero, it says nothing about R3-Rn which may all have different values and form different potential dividers.