Electrical
Early automobiles used a magneto for ignition, which provided no accessory power.
The first electrical accessory connection was supplied by a DC generator. Voltage varied with engine speed and because of technological limitations, complicated mechanical devices were used to regulate it. Even so, voltage at idle was too low to be useful. A lead-acid battery was used to provide proper voltage when the generator could not, and was recharged at higher engine speed or lower electrical load. The automobile self starter was an early engine system to use this.
Lighting, which had previously been provided by kerosene lamps or gas lamps, was one of the first common electrical accessories.
Early systems used 6 volts, but 12 volts became the standard because it provided greater power with less current. The original DC generator was replaced by an alternator controlled by a voltage regulator. Due to mechanical and electrical properties, it is more efficient to first produce alternating current and then immediately convert it to direct current. By regulating the current sent to the alternator's rotor and thus the strength of the magnetic field, a stable voltage can be produced over a wider range of engine speeds.
Starting, lighting and ignition systems of most gasoline-powered vehicles remain as 12 volt systems. Diesel-powered vehicles, including mobile construction equipment and heavy trucks use 24 volt electrical systems, as do many military vehicles. Research is ongoing into adopting a 42-volt electrical system standard for automotive electricity, but the entire electrical system will have to be redesigned and new components manufactured to work with the higher voltage. The main advantage of higher voltage is that electrical components can be made with less metal, saving weight and cost, and improving energy efficiency.
Most modern systems, such as power windows, power seats, and power door locks, are electrically powered. Electrically driven power steering systems have been developed and are used in numerous models. High-efficiency all-electric refrigerant compressors for air conditioning are starting to be used, especially in hybrid or all-electric vehicles.
The cigarette lighter receptacle serves as a de facto standard for use of portable 12 volt equipment in or near an automobile.
Read more about this topic: Automobile Accessory Power
Famous quotes containing the word electrical:
“Few speeches which have produced an electrical effect on an audience can bear the colourless photography of a printed record.”
—Archibald Philip Primrose, 5th Earl Rosebery (1847–1929)