Series and Parallel Circuits

A series circuit has one path for all the electrical components connected. This type of circuit can put a strain on the wire connecting the components and the wire can get excessively hot. This type of circuit was at one time very common in a string of holiday lights. This was because a series circuit uses less wire and is thus cheaper to make into a series of lights. The big problem is that if one component (one light) in the series goes bad then all the lights in the series go bad. Finding that one bulb could require replacing and testing every bulb in the series one at a time. If two bulbs just happen to be bad it could really be difficult to find the two that are bad. In such a case it would be better to have one series of lights that you know are working and then as you take bulbs out of the series of lights that are not working you can use the working series as a test series.

A parallel circuit has multiple paths for the electrical current to follow. The voltage stays the same across all the components in the system, This type of circuit provides a path for the current to flow even should one component go bad. Typically you house would be wired in parallel so that if a ceiling light were to blow out it would not stop electricity from flowing in other circuits. At your main electrical box there is a group of switches or fuses that are designed to stop electrical flow if too much current is being drawn by the circuit which may be dangerously heating the wires to a point that might cause a fire.

Your house could potentially be wired quite a bit differently. All of the wall switches could be wired with very low voltage switches that lead to major switches in the ceiling that would throw a switch to turn on the light. This would lower the amount of heavy copper wire used in your home, but does take some heavy duty switches to be used in the ceiling. The wall sockets would be wired normally.

Today wiring around the kitchen sink or in the bathroom is typically required to be grounded with a "fault interrupt" system. This type of system will shut the electricity off almost instantly if sensors in the circuit sense that there is a short which could be potentially causing someone to be electrocuted. Such systems can be installed throughout a home.

Sometimes special arrangements of circuits have to be constructed. For example if you are on the first floor and about to go up a dark staircase you will want to throw a switch to turn on the light to make it easier to go up the stairs, but once you are at the top of the staircase, if your bedroom happens to be upstairs you may want another switch there to turn the light off so you can go to sleep. Such problems are easy for electricians to design. When we place electrical boxes outside the house they also must be properly protected from the weather and properly grounded.

Your automobile has an interesting electrical circuit. Through most of your car the metal of the car actually acts like one of the wires. Because the tires on the care are rubber they act as an insulation between the car and the ground. The paint on the car provides a layer of insulation between the surface of the car and you when you touch the car.