- I welcome your
questions and comments. -Charles Kim.
Email to me at firstname.lastname@example.org
The Laws of Circuit
- you can learn
and practice by just reading
Copyright. Charles Kim 2006
- Mesh Current Method
- What the Heck is the Mesh Current?
- Let's discuss about the identity of mesh
current first. What the heck is this illusive,
non-physical current? The tem current we use
is the current through an element, or element
current. On the other hand, mesh current is
defined as the current that exists only in the
perimeter of a mesh. In a simple single loop circuit
(a circuit for example with a voltage source connected
sequentially to two resistors in series), the term
current only in the perimeter is not
confusing at all. The mesh current along the only
mesh is the same as the element currents (the
current flowing through the source or the resistors).
- Mesh Current vs. Element Current
- In a circuit with more than 1 meshes, the
term mesh current is slightly confusing.
Especially two meshes meet together at a branch than two
different mesh currents assume to flow in the same
branch! In a branch, how can we have two mesh
currents? The answer is the mesh current is
the invention of convenience. Think about this
way. In an element or branch where two meshes meet
together, any current (element or branch. Actually
two are the same) can be taken as a net current of two
imaginary currents flowing through the branch.
- Cash Flow again
- Cash Flow is a good analogy for the branch
current. Then, your income and expense are two mesh
current. The cash flow of your household or your
account is determined by income minus expense. When
you check your monthly balance, you see only the cash
flow: how much gain or loss do you see in the
sheet. Not each income of expense.
- KVL in Disguise
- We can say this statement, then, that mesh
current method is actually applying KVL around a mesh
with net voltage drop across an element.
- Order of KVL Application
- Here is the order of mesh current method
- a. Assign mesh currents to the meshes
- b. Using Ohms Law, express the
voltages in a mesh in terms of the mesh current
- c. Apply KVL to each mesh
- d. Solve the resulting simultaneous
equation to get the mesh current