Conventional Current vs Electron Flow

© 2015 Chris E. Chaulk V T R 1 R 2 R 3 I T I T
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Conventional Current assumes that current flows out of the positive terminal, through the circuit and into the negative terminal of the source. This was the convention chosen during the discovery of electricity. They were wrong!

Electron Flow is what actually happens and electrons flow out of the negative terminal, through the circuit and into the positive terminal of the source.

Both Conventional Current and Electron Flow are used. Many textbooks are available in both formats.

Conventional Current Example
Floyd, 1989, Principles of Electric Circuits, 5th edition, Conventional Current Version.

Electron Flow Example
Floyd, 1990, Principles of Electric Circuits, 4th edition, Electron Flow Version.

In fact, it makes no difference which way current is flowing as long as it is used consistently. The direction of current flow does not affect what the current does.

In general, high school Physics and two year technician programs use Electron Flow.

But three year technologist and university engineering programs use Conventional Current. Certain symbols (ex. diodes and transistors) and rules (ex. Right-hand rules) were created using Conventional Current. Changing from Conventional Current to Electron Flow would cause a degree of confusion for old and new students and errors would occur, so Conventional Current was kept to ensure there was no confusion with those already trained with Conventional Current. Two systems may seem confusing, but as long as usage is consistent, it really is not!

You must realize what convention is being used because the rules change. Ex. Right-Hand rules in Conventional Current become Left-Hand rules in Electron Flow. Example

Throughout this course, Conventional Current is used. Therefore always assume current flows out of the positive terminal of the source.

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