Electrical polarity is a term used throughout industries and fields involving electricity. There are two types of poles: positive () and negative (-). This shows the electric potential at the end of the circuit. The battery has a positive terminal (pole) and a negative terminal (pole).
Video Electrical polarity
Current Directions
Conventional currents flow from positive poles (terminals) to negative poles. Electrons flow from negative to positive. In a direct current (DC) circuit, current flows in one direction only, and one pole is always negative and the other pole is always positive. In a series of alternating current (AC) two poles alternating between negative and positive and the direction of current (flow of electrons) reverses periodically.
Maps Electrical polarity
Convention for identification
In DC circuits, positive poles are usually marked red (or "") and negative poles are usually marked black (or "-"), but other color schemes are sometimes used in automotive and telecommunication systems. Polarity symbols are often used where DC is supplied through coaxial power connectors.
In a car battery, the positive pole usually has a larger diameter than the negative pole.
Modern cars have a negative earth electrical system. In this case the battery negative terminal is connected to the vehicle chassis (metal body work) and the positive terminal provides direct cable to various systems. However, many older cars are built with positive earth electrical systems, in which case the battery-positive terminal is tied to the chassis and the negative terminal for live broadcasting.
AC System
In an AC system two cables from the polar circuit repeated many times per second. In electric systems, all cables carrying the same instantaneous polarities at all times will have common identification schemes, such as wire color. Depending on the conventions used for power system wiring, color coding or other marking may also exhibit additional properties of conductors, such as its role as neutral in the power circuit. In an AC polyphase system, identifying common-owned phase cables is important to ensure proper operation of the circuit.
Where an alternating current circuit is used to carry a signal such as audio, polarity is also required to ensure proper system functionality. For example, a set of loudspeakers used for stereo music reproduction will have all device terminals and cable marked to ensure the same instantaneous polarity, so that the resulting sound produced by each speaker element is in the same phase and appropriately adds to the listener's ear.
See also
- Anode
- Cathode
- Electrical charge
- Polarity symbol
- Polarity (mutual inductance)
Source of the article : Wikipedia
0 Comments