This site will look much better in a browser that supports web standards, but it is accessible to any browser or Internet device.
If you experience any problems with the site, please contact Pete Hoffman immediately so corrections can be made. Pete can be reached on campus, via email at phoffman@swtc.edu or by phone at 1.800.362.3322 ext 2727.
Combination CircuitA combination circuit is one that has a "combination"
of series and parallel paths for the electricity to flow. Its properties
are a combination of the two. In this example, the parallel section
of the circuit is like a subcircuit and actually is part of an
overall series circuit. 

INTRODUCTIONA "COMBINATION CIRCUIT" is a circuit that is a blend
of series paths and parallel paths. See Figure for a visual explanation.
Most circuits are of this variety. Don't be afraid to tackle these
circuits as far as the math goes. You merely have to break each
part of the circuit down into either a series circuit or parallel
circuit. Here's how this is done: 

BASICSYou must first figure out the resistance of each individual parallel
path in the circuit. Let's take the circuit to the right as an example.
There is an 8 Ohm resistor in series (R1) and two 4 Ohm resistors
in parallel, R2R3 (Note: The  means that the two resistors are
in parallel). To figure out the total resistance of that section
of the circuit we use the following: Find the resistance of the parallel circuit using the parallel formula.


Now that you know the total resistance of the circuit you can figure out the total amperage using Ohm's Law.
From here you can figure out each components voltage drop or current. 

The best advice in finding the values for a combination circuit is to first break each part of the circuit down into series and parallel sections and follow those formulas. Once that is complete, combine them for your main calculations. 