Electric Current

We cannot directly observe the electrically-charged particles that produce current. It is usually not important to know whether the current results from the motion of positive or negative charges. Early scientists made an unfortunate choice when they assigned a positive polarity to the charge that moves through ordinary wires. It seemed logical that current was the result of positive charge in motion. Later it was confirmed that it is the negatively-charged electron that moves within wires.

The action of some devices can be explained more easily when the motion of electrons is assumed. When it is simpler to describe an action in terms of the motion of electrons, the charge motion is called electron flow. Current flow, conventional current, or Franklin convention current are terms used when the moving charge is assumed to be positive.

Conventional current flow is used in science almost exclusively. In electronics, either conventional current or electron flow is used, depending on which flow is most convenient to explain the operation of a particular electronic component. The need for competing conduction models could have been avoided had the original charge-polarity assignment been reversed.