AC or alternating current is the most common form of electrical distribution. It is sent from power generating stations down transmission lines at very high voltages and long distances before it reaches the end user at a home or business.
One reason for such high voltages is cost and efficiency in electricity delivery. Since power available is a product of volts x amps, the higher the applied voltage, the lower the current draw will be when power is being consumed. Since electrical wire is sized on current draw (i.e. the higher the current, the larger the wire) a very high voltage is used to transmit electricity long distances.
For example:
A 1200 watt hair dryer will draw 10 amps when plugged into a 120 volt household outlet. (1200 watts divided by 120 volts = 10 amps).
The same 1200 watt hair dryer plugged into a 240 volt outlet will only draw 5 amps (1200 watts divided by 240 volts = 5 amps)
Notice the wattage or power consumed stayed the same in both cases. Only the voltage and amperage changed.
This is where a transformer comes in. Having thousands of volts of electricity available in your home to power appliances would obviously be extremely dangerous. A transformer, usually mounted on a pole or in the case of underground power distribution a ground level kiosk, steps down the voltage to a safer level. A transformer has no moving parts and very low losses making them up to 99% efficient. They can also be used to step up voltage providing a wide range of power possibilities for industrial and commercial applications.
No comments:
Post a Comment