Contact Us - Tell A Friend - Free-Ed.Net Home

Basic Circuit Analysis
Combination Series-Parallel Circuits

Section 3-1 Resistance in Combination Circuits

Resistive circuits in the "real world" aren't always strictly series or  strictly parallel. In the "real world" of electronics, most circuits  are combinations of  series and  parallel arrangements. Hence the general name, combination circuits.

 Definition Combination CircuitsCombination circuits include both series and parallel  connections.

Here are examples of combination circuits:

Your objective in this chapter is to learn how to analyze combination circuits.

Series-Parallel Combination Circuits

 Here is one of the two major types of combination circuits. Resistor R1 is connected  in series with the rest of the circuit. The rest of the circuit, consisting of resistors R2 and R3, is  a parallel combination.The product-over-sum equation for total resistance of  this circuit is: RT = R1 + R2 || R3 R2 and R3 are connected in parallel, and their combined resistance of is indicated by  R2 || R3. Resistor R1 is connected in series with R2 and R3 , and that fact is indicated by the + sign between R1 and the other two resistors. A Simple Series-Parallel Circuit

Parallel-Series Combination Circuits

 This is  the second of the two major types of combination circuits. Resistor R1 is connected  in parallel with the rest of the circuit. The rest of the circuit, consisting of resistors R2 and R3, is  a series combination.The product-over-sum equation for total resistance of  this circuit is: RT = R1 || (R2 + R3) R2 and R3 are connected in seriesl, and their combined resistance of is indicated by  R2 + R3. Resistor R1 is connected in parallel with R2 and R3 , and that fact is indicated by the || sign between R1 and the other two resistors. A Simple Series-Parallel Circuit

The circuits you will be analyzing through the remainder of this chapter are extended variations of these two basic combinations.

 Note Students sometimes question the value of spending so much time solving combination circuits. The real value lies in the analytical skills that you acquire and  develop by means of these exercises -- skills that apply to much more than analyzing resistor circuits, from testing circuits for the next generation of smart phones our troubleshooting a mainframe computer.