Definition
Electric current considered to flow from the positive terminal of a source, through the external circuit, to the negative terminal. This is the direction opposite to the actual movement of electrons, but it is the standard convention used in most electrical diagrams, formulas, and aircraft wiring schematics.
Plain English
When we talk about current flowing in a circuit, we usually describe it as moving from positive to negative, even though the electrons themselves are actually moving the other way. It's a chosen direction we agree to use so that everyone reads circuits the same way.
Context Anchor
Seen in aircraft electrical system descriptions, circuit diagrams, wiring discussions, and basic electricity lessons for pilots and mechanics.
Derivation
Conventional' comes from the Latin 'conventio,' meaning 'an agreement.' The name reflects exactly what it is — an agreed-upon direction for current, established before electrons were discovered. Once electrons were found to actually flow the opposite way, the original convention was kept to avoid rewriting every textbook and diagram.
Why Pilots Care
Correct use prevents confusion when reading wiring diagrams or tracing faults in aircraft electrical systems.
Analogy
It is like using north at the top of a map. The map convention helps everyone read the same picture the same way, even though it is not the only possible way to draw the world.
Intuition Check
Do not read “conventional” as meaning “ordinary” or “old-fashioned” here. In this term, it means “the agreed direction used for electrical diagrams”: positive to negative.
Example Sentence 1
On the wiring diagram, conventional current flows from the battery's positive terminal through the bus bar to each circuit breaker.
Example Sentence 2
When calculating voltage drop across a landing light circuit, use conventional current direction from positive to negative.