Basic Electrical Theory

[His Dudeness]

I found this very interesting and easier to understand than the wife. Strangely she preferred to watch Emmerdale or some such fiction.  :\

Good I'm glad you found it interesting I'll keep adding to it if it's useful. That first post hopefully gets across a good idea of what Voltage, Current and Resistance are. For working on bikes the exact scientific definitions aren't that important but if you can get a clear picture in your head of what Voltage, Current and Resistance are the rest of electrics like wiring diagrams or figuring out how components work comes to you a lot easier.

To summarise that first post it basically says atoms have positive protons and negative electrons. Atoms always want to have an equal number of positive protons and negative electrons, which is to say that they always want to be electrically balanced. When they're not balanced (due to gaining or losing electrons) the need to get back to being balanced creates a force between areas of relatively opposite charge that attracts the opposite charge together so the atom is balanced again. That force is called Voltage.

In a battery the imbalance is caused by an excess of electrons at one point and a deficit of electrons at the other point causing one point to be more negative and the other to be relatively more positive. When you provide a path for the electrons to flow (i.e. a conductor) the Voltage caused by the imbalance "pushes" electrons through the conductor. The battery keeps "pushing" electrons until both sides of the battery are balanced and have equal charge (i.e. the battery has 0 Volts difference between the positive and negative sides). The uniform flow of electrons along the conductor is called Current. Resistance is the opposition to the flow of Current.