Tuesday, May 18, 2010


To start out with, I will explain what a DC circuit is. DC stands for direct current, and it is the type of circuit that has constant voltage, constant current, and resistors. An electrical circuit will be connected by wires, and the current will travel through these wires. I will now explain the different types of DC circuits.

Here is an example of a series circuit.

In this type of circuit, the current is the same at all points along the wire. This is proven by the equation, IT=I1=I2=I3. This makes sense because the current only has one path to flow through, therefore it will be the same. Also, in a series circuit, the voltage drop across the entire circuit is equal to the sum of the voltage drops in the circuit. This is shown by the equation, VT=V1+V2+V3.

Here is an example of a parallel circuit.

In this type of circuit, the total current is equal to the sum of the currents throught each resistor. This is because the electrons are able to flow through a new path created by each resistor, in other words, there are two or more different paths. This is proven by the equation IT=I1+I2+I3.In addition, the voltage drop across each branch is equal to the voltage of the source. VT=V1=V2=V3 shows this concept.

Here is an example of a complex circuit.

In this type of circuit, finding the current involves the equation I = V/RE. First, find the equivalent resistance of the different parts of the circuit need to be found. Then the sum of those resistances will be the equivalent resistance of the entire circuit.To find the voltage drop of each resistor, it is necessary to use the equation V=RI, but you need to plug in that specific resistor's resistance and total current. Also, sometimes you can use V2=V3=VT-V1. This is used to find the voltage across each resistor in a parallel circuit.

I hoped that this posting has helped you to gain a complete understanding of the fun filled circuit world!

1 comment:

  1. Your diagrams are very good!
    In the first paragraph even though you describe the various elements of a circuit, you do not give the two important characteristics of a circuit.
    Your explanations of current are perfect but you did not explain how voltage works other than just restating the equations.
    Please be sure that you understand how the circuits work as it is an important part of the final exam.