What is a Circuit?

In order to fully understand circuit theory it is necessary at the very beginning to discuss atoms. An atom is made up of protons, neutrons and electrons. It is the electrons that have the propensity to move to positively charged atoms. But these electrons cannot make the transition until there is a link between the negative area and positive area. This bridge between the two is referred to as a "circuit".

Once this link is made the electrons will move rapidly. Depending on the resistance and conductance of the material making the connection, electrons will try to get across as quick as possible. For more information about resistance and conductance, click here.

Electrons collide with atoms in the process of moving around. This slows down the electrons and changes their direction. The result of this is that they generate heat and lose energy to th atoms.

Electrical current is the flow or movement of the electron charges. Within a circuit, electrons move from a negative pole to a positive pole. When the positive pole of an electrical source (battery, power panel, etc) is connected to a negative pole, this creates a circuit.

Current measures the number of electrons that are allowed across a circuit. This is measured in amperes or amps for short. In fact, one amp equals 6,250,000,000,000,000,000 (6.25 x 10¹⁸) electrons moving across a circuit every second. Because this is such a large number, it is simply called a "coulomb" after Charles A. Coulomb who helped discover what electrical current is.

In essence, a circuit can be msomething large, such as a megawatt generator, or something very small such as a microelectric chip. Circuits transfer, and more importantly, control electricity. A circuit breaker controls a circuit by either opening the circuit (no current flow) or closing the circuit (full current flow). Not only that, it acts as a safety device by opening if there is an excessive amount of current.

For more information about circuits, click here to go to the main Circuits page and follow the links to the other topics.

Search This Site

Custom Search

Subscribe!