By April Kohl, Updated Mar 24, 2022
Parallel circuits, while offering multiple paths for current, can introduce design complexity, variable current distribution, and power‑supply constraints.
In a series arrangement, components are connected end‑to‑end, forming a single path for the current. Every device experiences the same current, and the total voltage drop equals the sum of individual drops.
In contrast, a parallel network resembles a ladder. The voltage across each branch is identical, but the current splits according to each branch’s resistance.
Regardless of the number of power sources, a parallel circuit presents the same voltage across every branch. If different voltages are required at specific points, external resistors or voltage regulators must be introduced.
Because current divides among branches, each path carries a different amount of current, governed by its resistance. Adding branches continually raises the total current drawn from the supply. Engineers must verify that the power source can deliver this increased current; otherwise, the circuit may become starved.
When new branches are introduced, the total resistance of the network drops, increasing overall current. The only way to raise the effective resistance is to place resistors in series with existing branches or add series components.
