How Auto-detecting Power Converters Work

An auto-detecting power converter
An international power adapter and converter kit makes traveling with your electronic gadgets possible. See more pictures of essential gadgets.
©­ Rosenberg

Erma Bombeck once wrote, "When you look like your passport photo, it's time to go home." Of course, if you have the right equipment with you, such as travel hairdryers and curling irons, you can hold that passport look at bay just a little bit longer. Plus, when you travel you need to bring along all sorts of travel gadgets: a digital camera to document your trip, a laptop to keep in touch with everyone back home and even an MP3 player to tune out your traveling companions.

Yeah, travel is a lot cushier than it used to be; that is, until all your grooming and travel gadgets run out of juice. If you're overseas when you attempt to recharge them you could be in for a nasty shock -- literally.


Not every country uses the same type of electrical power. That means that something that plugs into the wall in the United States will most likely will be useless in Europe and Asia. Making things more confusing is that there are lots of different levels of voltage and a couple of different types of current. So if you buy a specialized travel gadget for one region, it may not work in another.

That's where power converters come in. A power converter itself can be a very useful travel gadget. Power converters plug into a wall socket and convert the electricity from that power source into electricity that a particular gadget can use. In years past, if you traveled a lot, you'd have to buy a power converter for every region you visited. That meant knowing what kind of power each of your travel gadgets required and what electrical voltage and current the region you were traveling in would provide.

These days, you don't need to be a near-electrician to travel. Auto-detecting power converters can plug into any power source, detect the electrical voltage and current available and convert it to the type you need -- making them the Rosetta Stone of travel gadgets.

Keep reading to learn more about how auto-detecting power converters work and how they can help you stay connected the next time you go abroad.


Mechanics of Auto-detecting Power Converters

Laptop power cable
The power cable for your laptop converts AC power to DC power.
© Guhl

So, how do auto-detecting power converters work to power your travel gadgets? In the United States, we use 110-volt AC power -- AC stands for alternating current. That means that the current reverses direction as part of a cycle. DC, or direct current power, always has the current running in the same direction.

You probably don't think about what direction your electrical current in running in very often. After all, you can't see it and as long as it's providing power for your stuff, why think about it, right? Well, not thinking about it isn't really a problem; that is, until you go to Germany for a conference after spending weeks on your presentation and you arrive at the meeting site only to find that your laptop is useless.


Power converters take whatever type of electrical current is available, AC or DC, as well as whatever voltage is available, and convert it into the type of electricity you need. You may already have some limited experience with something called a DC-to-AC power inverter in your vehicle. Most cars and trucks use 12-volt DC power supplied by the vehicle's battery. If you've ever been able to plug anything from your house -- like a laptop computer or a toaster -- into your car, then you've used a power inverter that was built to take 12-volt DC power and convert it to 110-volt AC power. Some cars and trucks come from the factory with this equipment pre-installed, while others rely on aftermarket parts to make on-the-go computing (or toasting) possible.

Unlike a car's DC-to-AC power inverter, or a country-specific travel power converter, auto-detecting power converters can transform any current or voltage into another current or voltage. A basic power converter contains a power supply and an interior circuit. The interior circuit moves the current rapidly, stabilizing it and changing it into the type of electricity required. Most people might not realize that we actually use power converters all the time, in most cases without even noticing. For instance, if you have a laptop computer, it actually runs on DC power, because that's the electrical current that batteries provide. However, if your laptop is plugged in, it's taking AC power from a wall socket. Your laptop's power cord has an in-line converter that changes the AC power from the wall socket to DC power for the laptop's use.

Auto-detecting power converters are a little different. They're "smart" converters. While the converter on your laptop only takes one form of current and converts it to another, an auto-detecting power converter can convert a variety of different power sources into useable power for your devices. If you travel frequently, an auto-detecting power converter can be a key tool to keep your life humming right along. On the next page, find out how to use an auto-detecting power converter.


Using Auto-detecting Power Converters

The real beauty of auto-detecting power converters is that they're so easy to use. Without an auto-detecting power converter, if you were on an extended multi-country trip and wanted to use some electronics from your home, you'd have to almost become an apprentice electrician. You'd have to know everything about your numerous travel gadgets' power needs, plus everything about the power supply in the countries you were traveling in. Finally, you'd need a converter for each location -- and you'd have to keep them all straight.

An auto-detecting power converter combines all of those power converters into one easy-to-use gadget. Because outlet sizes and shapes vary from country to country, most auto-detecting power converters have attachments that allow the power converter's wall plug to be configured to fit whatever voltage of current is at hand. Once the converter is set up to fit the wall socket, you simply plug it into the wall and plug your gadgets into the converter -- like you might use a power strip at home.


When shopping for an auto-detecting power converter, it's a good idea to look for one that works in as many different regions as possible. Also, having one with a surge protection feature is a must, especially if you travel to areas with frequent power surges or interruptions in power. Finally, consider the number and type of gadgets you usually travel with. If your power converter only has one outlet slot, you'll only be able to use or charge one of your gadgets at a time. You'll probably want to get a converter with two or three power slots so you can use multiple gadgets simultaneously. Some auto-detecting power converters also have USB ports, which makes charging gadgets like MP3 players easy.

When you're packing for your next trip abroad, you should feel free to bring as many of your gadgets as you like -- just remember to also bring an auto-detecting power converter so you can actually use them.

If you'd like to read more about travel gadgets and other related topics, follow the links on the next page.


Lots More Information

Related HowStuffWorks Articles


  • Leading Outdoor Technology Supply, LLC. "Power Inverters and How They Work." (Jan. 27, 2009)
  • Ledwich, G. "DC-DC Converter Basics." 1998. (January 27, 2009).
  • National High Magnetic Field Laboratory. "Alternating Current." 1995. (Jan. 27, 2009)
  • "What is a Power Converter?" 2008. (Jan. 27, 2009)
  • TEMCo US. "Frequency Converters." 2006. (Jan. 27, 2009)­