The Difference Between AC and DC Electrical Current


When it comes to electricity, most people’s knowledge is extremely limited. Some know that you can find electricity in two different types: AC and DC, but very few people can tell you what the difference between these formats actually is and why it’s so important. So to help you get a better understanding of that force that flows along power lines and through your walls to make your microwave oven work, let’s take a closer look at the crucial difference between AC and DC power.

What are AC and DC?

AC and DC are abbreviations for the two different types of electrical current we find today. AC stands for alternating current and DC stands for direct current. Alternating current is what most people think of when it comes to electricity: it’s the stuff that flows through your walls, along the power lines over your head, and is distributed from power plants around the country. Everything that plugs into your walls in some way shape or form utilizes alternating current power, which generates energy by periodically reversing the flow of electrons along a wire. Passing this flow through a resistor is what gives us the energy that powers our devices.

Unlike alternating current where electrons reverse back and forth, direct current allows electrons to flow directly through a resistor in a straight line with constant voltage. Think of it like a water wheel over a large river: the river catches resistance at the water wheel, causing the wheel to turn, creating energy. This means you need a constant flow of electrons along a closed circuit in order for direct current to properly operate. Most people are usually surprised to learn that their devices actually run on DC power, even though they plug into the wall and draw AC energy. This is because their power supplies have a rectifier, which is a device that turns AC current into DC.

Why AC and DC?

Why do we utilize two different types of electricity? Wouldn’t it be easier to pick one and stick with it? The answer is each type of current has different strengths and weaknesses. AC current can be easily crated and scaled to extremely high voltages, where it can be sent with little resistance along power lines. For this reason, most power lines run at tens or even hundreds of thousands of volts with very little energy loss, meaning you can run a much lower current, generate less heat, and have an overall much more durable electrical grid.

DC voltage doesn’t have this ability. It’s much more difficult to transform DC current into higher voltages, and even then DC current tends to lose a lot of power when sent over long distances, so you would need to live within a couple of miles of a power plant at the furthest if your house was powered by it. However, DC current provides and extremely stable and constant voltage, which makes it great for powering electronics, especially ones that have lower voltage requirements. This also means DC current is great for another application: batteries, which are small capsule of stored electron energy that is then used to create this current, thus powering your device.

Do you need an electrical repair in your home? Call the Marietta electricians at Lightning Bug Electric today at (404) 471-3847 to schedule your service.

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