Basic Electronics

Consider the following analogy. The water system in your house probably has a “tank” located somewhere high, maybe in the loft. You have pipes that link it to taps (faucets) somewhere lower, say, in your kitchen. When you open a tap the water flows. In this analogy the force pushing the water out of the tap (gravity) is analogous to voltage and the quantity of water flowing per second represents the electrical current. In the electrical circuit equivalent of this we could imagine a battery providing the voltage and wires linking the + and – terminals via a switch. When the switch is closed current flows through the wires. In this case the current is a flow of electrons, invisible to the naked eye but unmistakably present. One word of warning … in general it is not a good idea to connect a wire directly across the terminals of a battery since this provides a path of very low resistance for the current and will very quickly drain the battery and ,depending on the wire used and the capacity of the battery, may result in overheating.. It is analogous to opening the tap fully or, in fact, removing it completely allowing the water to flow un-restricted out of the tank.

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