文档介绍：Reading 7 Ron Bertrand VK2DQ
SERIES-PARALLEL CIRCUITS
In many circuits, ponents are connected in series to have the same current,
while others are in parallel for the same voltage. When analysing and doing calculations
with series-parallel circuits you simply apply what you have learnt from the last two
readings.
In the circuit of figure 1 below, we could work out all the voltages across all of the
resistances and the current through each resistance and then total resistance. For now I
am just going to walk through the simplification of this circuit to a single resistance
connected across the 100 V source.
Keep in mind that any circuit (resistive) can be reduced to a single resistance. This is
particularly useful when e to do transmission lines and antennas.
For now let's have a go at simplifying the circuit of figure 1. There are many ways to go
about this problem. The method I prefer is to start at the right hand side and work my way
back to the source, simplifying the circuit as I go.
Figure 1.
On the right hand side we see R3 and R4 in parallel and each 12Ω. Do you remember the
short cut method when parallel resistances are all the same value? Divide the value of the
branch by the number of branches: 12Ω/ 2 = 6Ω.
Page 1
Replace the parallel pair of
R3 and R4 with a single
resistance R7 as shown