What is dc current

Both types of power are essential; one is not "better" than the other. In fact, AC dominates the electricity market; all power outlets bring power into buildings in the form of AC, even where the current may need to be immediately converted into DC power. This is because DC is not capable of traveling the same long distances from power plants to buildings that AC is. It is also a lot easier to generate AC than DC due to the way generators turn, and the system is on the whole cheaper to operate—with AC, power can be hauled through national grids via miles and miles of wire and pylons easily.

DC primarily comes into play, where a device needs to store power in batteries for future use. Smartphones, laptops, portable generators, torches, outdoor CCTV camera systems… you name it, anything battery-powered relies on storing DC power. When batteries are charged from the mains supply, AC is converted to DC by a rectifier and stored in the battery. This is not the only method of charging used, though.

If you have ever charged your phone using a power bank, for example, you are using a DC power supply rather than an AC one. In these situations, DC-DC power supplies may need to change the voltage of the output in this case, the power bank for the device's in this case, the phone use. Have you enjoyed reading this article? Then follow us on LinkedIn and stay up-to-date with daily posts about the latest developments on the industry, products and applications, tools and software as well as research and development.

The equation to the right of the equals sign describes how the voltage changes over time. V P is the amplitude. The sin function indicates that our voltage will be in the form of a periodic sine wave, which is a smooth oscillation around 0V.

This is given in the form of hertz or units per second. The frequency tells how many times a particular wave form in this case, one cycle of our sine wave - a rise and a fall occurs within one second. As time varies, our waveform varies. Phase is a measure of how shifted the waveform is with respect to time. It is often given as a number between 0 and and measured in degrees. We can turn to our trusty outlet for a good example of how an AC waveform works.

In the United States, the power provided to our homes is AC with about V zero-to-peak amplitude and 60Hz frequency. We can plug these numbers into our formula to get the equation remember that we are assuming our phase is 0 :. We can use our handy graphing calculator to graph this equation.

If no graphing calculator is available we can use a free online graphing program like Desmos Note that you might have to use 'y' instead of 'v' in the equation to see the graph. Notice that, as we predicted, the voltage rise up to V and down to V periodically. Additionally, 60 cycles of the sine wave occurs every second. If we were to measure the voltage in our outlets with an oscilloscope, this is what we would see WARNING: do not attempt to measure the voltage in an outlet with an oscilloscope!

This will likely damage the equipment. This is also correct. When talking about AC since the voltage changes constantly , it is often easier to use an average or mean. To accomplish that, we use a method called "Root mean squared. Home and office outlets are almost always AC. This is because generating and transporting AC across long distances is relatively easy. At high voltages over kV , less energy is lost in electrical power transmission.

Higher voltages mean lower currents, and lower currents mean less heat generated in the power line due to resistance. AC can be converted to and from high voltages easily using transformers. AC is also capable of powering electric motors. Motors and generators are the exact same device, but motors convert electrical energy into mechanical energy if the shaft on a motor is spun, a voltage is generated at the terminals!

This is useful for many large appliances like dishwashers, refrigerators, and so on, which run on AC. Direct current is a bit easier to understand than alternating current. Rather than oscillating back and forth, DC provides a constant voltage or current. The tank can only push water one way: out the hose. Similar to our DC-producing battery, once the tank is empty, water no longer flows through the pipes.

DC is defined as the "unidirectional" flow of current; current only flows in one direction. Voltage and current can vary over time so long as the direction of flow does not change. To simplify things, we will assume that voltage is a constant. For example, we assume that a AA battery provides 1. What does this mean? It means that we can count on most DC sources to provide a constant voltage over time. In reality, a battery will slowly lose its charge, meaning that the voltage will drop as the battery is used.

For most purposes, we can assume that the voltage is constant. Almost all electronics projects and parts for sale on SparkFun run on DC. Examples of DC electronics include:.

Almost every home and business is wired for AC. However, this was not an overnight decision. Skip to main content. Your health and safety are our highest priority during this time.

Click here for our precautionary measures. AC Your home or office receives electricity in the form of wave-like AC current, which is capable of changing direction and voltage from higher to lower current with the aid of transformers. DC The consistent and constant voltage of DC power supplies electronics that use a battery, such as your mobile device or smartphone.

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