10/11/2012
To help understand basic concept of circuitry, imagine a highway. Along the path of this highway lies a drawbridge. This drawbridge is a switch. when the bridge is open, the flow of traffic is halted. The total number of our cars has not changed, but the flow of those cars has ceased. Voltage then is represented by the number of cars on our fictional highway. By definition, voltage is the potential for electricity to do work. The cars will represent electrons -- which are the workers of the circuit. When our drawbridge closes, this potential is released and the cars are able to flow to the other side of the drawbridge to their final destinations. The measure of voltage is the volt (V).
When our cars begin to flow to their destinations, the volume of cars in a given space at a given time and the speed at which they flow represents current. Current is the measure of the flow of electrons. Our cars must also have somewhere to go before they begin to flow. In a circuit, electrons must have a path to follow, a complete loop, before they are able to flow and do work. Current is measured in amperes, or amps for short (A). Again, the total number of cars on the highway represents our voltage, and the number of cars at one point along with the speed of those cars represents current in the circuit.
