What is the advantage and disadvantage of AC and DC Adapters? How to work Alternating Current for you!

Most of us have several AC adapters in our home; we use them for so many things from charging laptops to charging our cell phones. You may even have some in your home but not even know it- when AC adaptors are used to charge electronic devices, they’re often referred to simply as “chargers.” However, an AC adapter is a type of external power supply, also referred to as plug-in adapter or power brick, that can charge anything from a cell to a camera battery. When it comes to AC adapters, they should be a staple item in every professional cameraman’s toolkit. If this is the first time you’re hearing of the importance of A/C adapters, you have no idea what you’ve been missing out on.

So the first question many people have about AC adapters is obvious: what does an AC adapter do? An AC adapter acts as a way to make electronic equipment, such as professional cameras and laptops, lighter and smaller by providing a way to recharge the device instead of inserting a complete internal power supply. Can you imagine how large a laptop would be if its battery had to last, well...forever? AC adaptors can charge a variety of devices because of the versatile way in which they alternate the direction of the electronic current and convert voltage levels.

Another common question is: What makes AC adapters special? AC adapters work differently There are two types of adaptors: AC adapters and DC adapters. DC stands for direct current, which means that the electric charge will flow in one direction; however, AC adapters have an alternating current, meaning that the electric charge flows both ways. The electricity in AC adapters constantly switches directions. Alternating current can be beneficial because the electricity voltage can convert easily to either high or low voltage levels, which typically makes AC adapters the most economical option.

In the professional photography industry, AC adapters are more than helpful- they’re necessary. Those who work in professional photography prefer AC adapters that can charge batteries while also charging a video camera. AC adapters are a convenient tool that make the lives and jobs of professional photographers much easier. At DandO Lighting, we offer AC adapters better than the leading brand. They are extremely versatile, as they can charge anything with a dtap port and are very affordable. D&O Lighting is the official online retailer for Comer products and they do have quite a wide selection. One of the most popular AC adapters available on the site is the BCC2 battery, which can charge Sony and Anton Bauer Gold batteries with dtap sockets. The BCC2 can also charge replacement batteries; one charge will last 4-6 hours and can be recharged up to 500 times. In addition to their amazing products, DandO Lighting offers 24/7 customer service and are incredibly dedicated to satisfying their customers. They don’t just want to sell products- they want to get to know their customers so they can find a product that meets their needs perfectly. Whether you need to replace your AC adapter or purchase one for the first time, D&O is the place to go.

AC adapters convert a higher-voltage alternating current to a lower-voltage direct current for use with devices that require a relatively constant voltage (within a tolerance). Direct current is also required to recharge batteries, making AC adapters essential for electronic devices like laptops (see 1) and cell phones. Older AC adapters waste quite a bit of electricity in the form of standby power, but recent regulations and subsequent innovations have reduced the amount of electricity wasted considerably. See Standby power for more detailed information.

How it works

A simple AC adapter consists of a transformer, a rectifier, and an electronic filter. The transformer initially converts a relatively high-voltage alternating current that is supplied by an electrical outlet to a lower voltage suitable for the device being powered. A rectifier then converts alternating current into direct current. There are two separate types of rectifiers: the half-wave rectifier and the full-wave rectifier.

Half-wave rectifier

The half-wave rectifier effectively blocks current flow in one direction through the use of a diode (see 2). This creates a pulsating direct current. Due to half of the current being blocked, much of the supplied energy is lost, and the mean voltage of half-wave rectified power is lower than that of full-wave rectified power.

Full-wave rectifier

There are several types of full-wave rectifiers. Rather than blocking the electric current in one direction, these rectifiers flip its direction so that a constant pulsing direct current is the output. A common type of full-wave rectifier is the full-wave bridge rectifier (See 3).

For more information about rectifiers, visit ElectronsTutorials or All About Circuits.

Smoothing

As seen in s 2 and 3, the output voltage of the two rectifiers still varies greatly. However, a constant voltage is required for most devices that operate on direct current. A smoothing circuit or capacitor is used to achieve this. At its simplest, a circuit component known as a reservoir capacitor or smoothing capacitor is placed at the output of the rectifier. Essentially it releases stored energy when no voltage is being output from the rectifier. This creates a fairly steady voltage. However, some ripples from the AC voltage remain (See 4).

Modern AC adapters

In modern use the most common adapter is the Switched Mode Power Supply (SMPS). These are considerably more complex than linear regulated power supplies and have clear advantages. The main advantage for SMPS is that it gives DC supplies that can deliver more power for a given size, cost and weight of the adapter.

SMPS is used in many applications such as battery chargers, laptops, vehicles, LED lighting, and other consumer electronics. To learn more about how SMPS units work, visit Learn about Electronics.

For Further Reading

For further information please see the related pages below:

• Direct current
• Alternating current
• Phantom power
• Or explore a random page!