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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What is Electronics?

Electronics refers to the flow of charge (electron) through non-metal conductors (often called semi-conductors), where as electrical refers to the flow of charge through metal conductors. For example, flow of charge through silicon which is not a metal would come under electronics whereas flow of charge through copper which is a metal would come under electrical. This distinction started around 1908 with the invention by Lee De Forest of the valve (triode). Until 1950 this field was called "Radio technics" because its principal application was the design and theory of radio transmitters and receivers.

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