What Is The Difference Between AC and DC Power Supplies?

Whether you're an aspiring electrical engineer or purchasing manager, or even a contractor, you're going to need to learn all about the difference between AC and DC power supply. This is a topic that can get pretty complicated - but it's important you get a good grasp on which of these power supplies best suits your needs.

Don't worry - today, we're going to answer one of the most common questions we get as a power supply retailer: what is the difference between AC and DC power supply?

Simply put, these are the two forms of electricity. While both are essential to getting electronics powered on and working, they do have key differences you must be aware of. And as you'll soon discover, one is not necessarily "superior" to the other. Let's get things started by quickly explaining what each power supply is.

What Is AC Power Supply?

An AC power current, or alternating current, is the style that dominates today's market. These are what primarily bring power into buildings - even in situations where that AC power is immediately converted to DC power. As the name suggests, the power flows in an alternating current - changing directions periodically.

This periodic change in directions is caused by the electrons in the power. Electrical currents are a direct result of the activity of these electrons, and they can move upward (positive) or downward (negative). Electricians and manufacturers refer to this change in direction as the sinusoidal AC wave. What causes this wave, though? Alternators at a power plant.

Alternators at a power plant are scaled-up versions of the alternators in your car or any other type of alternator for that matter. They all work more or less under the same principles. A wire loop is spun inside a magnetic field to generate energy. As the wire spins through areas of different magnetic polarities, the current changes - thus you have the alternating current.

Why does all of this matter? Well, because AC voltage travels in a wave-like motion it can reach further than DC power. You can probably already start to see why this is so advantageous. With that said, we still use DC power commonly today - what exactly is it?

What Is DC Power Supply?

DC power, or direct current, is exactly what the same implies. Here, power appears in a straight line - direct, so to speak. Direct current comes from a wide range of sources. Form batteries to solar cels, modified alternators to fuel cells, and more. What's really unique about DC power, though, is it can actually be sourced from AC power. This requires the use of an AC to DC power converter - we'll talk more about that later on. First, let's explain the advantages a DC power supply offers.

Because DC power is a linear source, it is far more consistent and reliable. It doesn't bounce around and change direction like AC does. As such, most electronics rely on it. They use batteries as the primary source of DC. With that said, though, there are also a wide array of devices that use AC power instead: including household appliances, lamps, and more.

So why are there two different power supplies? Do we really need both in our society? What is the difference between AC and DC power supply? Let's answer all these questions in the next section.

So, What Is The Difference Between AC and DC Power Supply?

We've broken down the basic foundation for what you need to understand AC and DC power supply. To truly understand each one and the differences they have, let's look at the pros and cons of each.

Advantages & Disadvantages Of AC Power

As you'll soon learn, AC power is far more common in households - and for good reason. It is incredibly easy to transform, first of all. Compared to DC power, you can transform AC power with ease using transformers and converters. This makes it a far more sustainable and suitable power supply as infrastructure.

There is another unique advantage alternating current has over direct current - and that is the ability to shut it off safely and with ease. Why is that? Well, because alternating current will periodically reach a voltage of 0 - the point at which shut off is safe. You'll also find that it is far more practical for certain situations because you don't need to distinguish between negative or positive.

But perhaps the biggest advantage of alternating current? How efficient it is to transport this power at large distances without a loss of efficiency. This is why we transport power from a power plant to an urban area using direct current. You'll experience far less power loss due to high voltage transmission. And while this power - transported at incredibly high voltages, sometimes up to 600,000v - cannot be used as is, remember that transforming it to a usable state is super simple.

All these advantages may have you wondering - are there any disadvantages of alternating current? Yes - as with all things, it is give and take. One such drawback of AC power supply is that it requires a higher voltage than the target voltage - meaning there will be some waste of power. And, this power supply source can be affected by coils and capacitors in a negative manner.

Advantages & Disadvantages Of DC Power

One of the main advantages of a DC power source is that there is no advance or delay in the current. Remember - direct current is constant and steady. It doesn't fluctuate. This means that all the electricity in a DC power supply flows through the load. As a result, power is more efficient. Of course, the main advantage of direct current power is that it can be easily stored within batteries, capacitors, and more.

However, direct current power also has a few drawbacks worth noting. For one, it can be tough to interrupt the current when necessary. Think about it like this: because a constant voltage is always applied to a direct current, you may experience issues when interruptions do occur. Potential issues include arcs (sparks) or even more serious problems like the risk of electric shock in surrounding areas.

You also must consider the cost of converting a direct current to an alternating current. Unfortunately, DC power must be switched to AC power and then back to DC once again. This process requires larger, most expensive equipment. One final disadvantage of direct current power is the havoc it can wreak on underground pipes, insulators, and other equipment required for power transmission. This is caused by the direct current itself - beating down on the exact same spots over time.

Is One Really Better Than The Other?

So, with all this said - is it really a case of alternating current vs direct current? Not exactly. As you now know, we really do need both. Certain scenarios will call for a direct current while others will be best suited for alternating current. And because we use both of these throughout society, you might as well familiarize yourself with the specific use cases for each power supply style.

Final Thoughts On The Difference Between AC and DC Power Supply

Now that we've answered the question - what is the difference between AC and DC power supply - there is just one thing left to do: get all your AC DC power supply needs at Bravo Electro. Whether you're looking for an open frame or enclosed frame power supplies, external or internal supplies, or even converters - we've got you covered. Whether you're looking for 12v power supplies, 24v power supplies, or even 48v DC power supplies.

We know power supply talk can get complicated. We're here to help simplify it for you. Whether you're building a project, upgrading some machinery, or just want to learn more about how to best solve your power supply needs - don't hesitate to reach out. We have electrical engineers on staff ready to assist you in making your electrical vision a reality. Let's do it together so you can rest assured you're getting exactly what you need for safe, efficient power supply!