Friday, August 5, 2011

Part Two

So last post I told ya'll that I would discuss KCL and KVL in this post.

First off KCL stands for Kirchhoff Current Law and KVL stands for Kirchhoff Voltage Law.

These laws are named after a German university professor, Gustav Kirchhoff, from 1824-1887.

First let's start with KCL. KCL is the sum of the currents entering a node is equal to the sum of the currents leaving the node.
 Here is an example:

the arrows indicate the direction of flow. So 4A+ab=4.5A+4A+2A Then use basic algebra to solve for ab.

Next We have KVL which is the sum of the Voltages in a loop is equal to zero. This is where the passive sign convention and polarity of an element is important.

Here is an Example: V1 is unknown, V2=2 volt, V3=4 volt, and V4=1 volt
When you add the voltages you add them by the terminal the loop enters. So this example would be V4-V1-V2+V3=0 so you enter the numbers from above and solve using algebra.

For a more in depth explanation of these examples check out

And remember the more you practice the better you will get.


  1. Argh. This post makes my feeble brain hurt...

  2. Hm, this isn't so bad. Pretty basic algebra. Glad this isn't hurting my head too much. :P

  3. There's a reason I stopped going for Computer Engineering after my first semester!

  4. Going to have to agree with sinclair on this one.. I kind of get the concept, but. Uh. Its late ;)

  5. I really like facts like these!