Resistors in a Mixed Connection
Look at which resistors are in parallel or in series and summarize them. Work from "inside" to "outside". Here is an example: The expected measurement voltage is to be calculated. Therefor, you have to determine the total resistance:
Resistors in Mixed Connection 1
Step 1: R1, R2 and R3 are parallel and can be combined to form a substitute response R1,2,3.
R1,2,3 = R1/3 = 300 Ω / 3 = 100 Ω
Resistors in Mixed Connection 2
Step 2: You can now see that R1,2,3 and R4 are in series. The equivalent resistance R1,2,3,4 can easily be determined by addition:
R1,2,3,4 = R1,2,3 + R4 = 100 Ω + 150 Ω = 250 Ω
This results in the following equivalent circuit:
Resistors in Mixed Connection 3
Step 3: Now we dissolve the parallel connection of R1,2,3,4 and R5:
R1,2,3,4,5 = R1,2,3,4 * R5 = 250 Ω * 300 Ω = 136,36 Ω
. R1,2,3,4 + R5 250 Ω + 300 Ω
Resistors in Mixed Connection 4
Step 4: What remains is a simple series connection. Calculating the total current which flows through R6 is now a simple exercise:
Rt = R1,2,3,4,5 + R6 = 136,36 Ω + 200 Ω = 336,36 Ω
It = IR6 = U = 24 V = 71,35 mA
. Rt 336,36 Ω
=> VMeasure = UR6 * It = 200 Ω * 71,35 mA = 14,27 V
