Most people turn on their cell phone or lamp and don't think how the item is powered. There are essentially two different power options: direct current (DC) and alternating current (AC). The two have a long history, and it's important to understand the two options and when we use each one. Once you understand AC electricity, you can better understand transducers and transformers.
Intro to the AC/DC Debate
The debate between AC and DC currents goes back to Thomas Edison and Nikola Tesla in the 1880s. The fight came to an expensive climax when Edison and Westinghouse (using Tesla's patents) both bid to supply electricity for the 1983 Chicago World's Fair. Edison offered to provide electricity for $554,000, but Westinghouse was able to provide the same service with his AC technology for $399,000. After this, AC became the most popular power source.
Explaining AC and DC Power
Direct currents (AC) can only go in one direction while Alternating currents (AC) can travel in both directions. An AC current transformer can change the voltage of AC, but this is not possible with CC.
DC powers things like batteries, fuel cells, computers, LEDs, and solar cells. It offers a steady current. The current moves in one direction, and when the power is empty, there is no more power source (a dead battery).
There are three ways to generate DC power:
- battery power
- when an AC generator is equipped with a commutator
- a rectifier- a device that changes AC to DC
AC powers the items you plug into the outlet into your wall. AC power allows for power companies to control the voltage, making it much easier to bring into people's homes. Power companies start with a large voltage and use transformers to bring it into our homes at a voltage that is safe to people. AC power in the United States uses a 60-cycle and 120volts. Electricity in Europe uses a 50-cycle. This is why you need a converter when you go to a European country.
There are several types of AC waveforms. The three most popular types of AC waves are:
- sine wave
- square wave
- triangle wave
Sine waves are by far the most popular form of AC current. This is what you see in most homes and commercial buildings. Digital and switching electronics use a square wave. Triangle waves are mostly used to test linear electronics such as amplifiers. For more information, contact a company that has a current transformer with 4 20ma output.
