The Hughes Telematics Device

The Hughes Telematics system is designed to link and monitor each of these on-board electronic systems as well as send and receive information via network connections. The end result: a fully networked vehicle.

­Right now, there may be a whole lot going on inside of your car or truck that you simply take for granted; especially if your ride is equipped with a factory-installed vehicle telematics system such as GM's OnStar or Ford's SYNC system. Both of these systems allow you to receive roadside assistance or automatically notify paramedics if your car is involved in a crash. It might even be integrated with a GPS and a turn-by-turn direction system of some kind. While on long trips, you can listen to songs through your hard drive based MP3 player, or passengers can watch their favorite movies on DVDs played through a built-in vehicle entertainment system. Meanwhile, electronic control units throughout your entire car are monitoring wheel slip, engine temperature, fuel mixture and hundreds of other variables, all while regulating the anti-lock brakes, traction control systems and other safety and control features.

Sounds pretty impressive, doesn't it? But what will the next generation of telematics technology be able to add to your driving experience? Well, it will integrate all of those features and functions into one cohesive system. Music, maintenance, safety and security, shopping and entertainment will all be combined and controlled through a Web interface. Your car will be fully networked. A platform that can deliver services that haven't even been thought of yet, all linked to a broader network of information. That's the future of automotive telematics technology as envisioned by Hughes Telematics, a company that's providing automotive telematics services to Chrysler and Mercedes-Benz starting in 2009.

This article will explain what the Hughes Telematics' system will do, and how it works to keep all of your car's electronic systems running in unison. And we'll even find out how telematics could let you purchase a song via iTunes -- while you're driving.

What is telematics?

The word telematics technically refers to any system by which a mechanical or electronic device communicates with other devices or with human users over a network. Over the years, the term has come to mean the specific use of on-board communication capabilities in automobiles. General Motors calls their telematics system OnStar, while Ford's system is called SYNC. At present, Hughes Telematics has not yet announced the brand name of their upcoming system -- since Mercedes-Benz does not typically allow third-party branded systems in their cars, whatever name Hughes chooses may only show up in Chrysler vehicles. ­

The Hughes Telematics system does not represent a revolutionary change from prior telematics systems. There will be additional services and options compared to current services such as OnStar, but Hughes will not instantly change the nature of the telematics industry. Rather, they're aiming to create a platform of vehicle information and safety services that can be built-on for years to come, offering the flexibility to create new technologies and services as customers demand them.

The key to this plan is in linking all of the various electronic systems already on board most modern vehicles. A car bought in the last 15 years most likely has an engine controller, a body controller, and several other electronic control units (ECUs). Some of these systems communicate with each other to some extent (we'll explain how shortly), but there isn't generally one processor than can understand data from all of the various ECUs, and certainly none of them are integrated with your MP3 stereo or LCD viewing screen. The Hughes Telematics system will access and interpret all of the information and make it available to the user.

Hughes Telematics System

The Hughes Telematics system is actually an intricate network of systems and features that can cross-communicate. Here are some of the features being touted by Hughes:

• Roadside assistance, emergency calling, automatic crash notification and stolen vehicle locator service -- These safety and security features are similar to those offered by other telematics systems, relying on GPS information and a cell phone connection. In addition to locating a stolen vehicle, the system can shut down a stolen car by cutting off the fuel supply. This feature could reduce the chance of dangerous high speed chases and increase the chances of recovering a stolen vehicle. Emergency calls are handled by Intrado, Inc., a company that is heavily involved in development of the 911 emergency response system in the United States [source: Hughes Telematics]. Intrado's system will be able to route emergency calls to the nearest available emergency response unit.

• Telematic navigation, turn-by-turn directions, real-time traffic information, traffic camera access -- Initially, Hughes Telematics-equipped cars will be able to receive traffic information from Hughes' own network, which will use numerous sources to develop traffic info. These sources include sensors built into traffic lights and other key locations, toll booths and traffic cameras. A few years down the road, data from each individual car could be incorporated as well, including speed, braking, and steering wheel position. Once all personal information is stripped away from the data, it can then be used to build a more complete and dynamic picture of current traffic conditions. Hughes has partnered with Concentrix Corporation to provide call centers to respond to customer care requests [source: Hughes Telematics].

• Vehicle maintenance reminders, diagnostic health check, recall reminder, remote emissions testing -- Currently, the various ECUs on a car can be accessed by a mechanic using an expensive piece of equipment known as a diagnostic scan tool. The Hughes Telematics system will allow the user to access diagnostic information through a Web interface, which can be configured to create maintenance reminders and automatic recall notices. Hughes already participates in a pilot program in California known as the Continuous Smog Check Testing Program. Volunteers with the proper equipment installed on their cars don't need to visit a mechanic for required emissions testing -- emissions levels are tested continuously, and an automatic notification is sent if levels ever fall out of compliance, without the user having to visit a mechanic for regular emissions tests.

• Local information, stocks, weather, sports, news, streaming and storage of music and videos -- Using Bluetooth wireless connections, cell phones, PDAs, MP3 players and other electronic devices can be integrated into the on-board telematics system.

The Telematics Control Unit

The heart (and brain) of the Hughes Telematics system is the Telematics Control Unit (TCU). The TCU is a small computer that listens in on the communications of other electronic systems in the car, then interprets and disperses that data as necessary. It accomplishes this by piggy-backing onto the Controller Area Network (CAN-bus) a communication system found in all modern cars. The CAN-bus acts as a communications bridge between all of the ECUs within the vehicle. Hughes' TCU pulls data from the CAN-bus -- this simplifies the system because it doesn't need to be wired into every single ECU in the car. It can get data from any ECU by simply listening in on the CAN-bus network. In some ways, it acts much like a mechanic's diagnostic scan tool, but it makes the data available to the driver in a number of user-friendly ways that are comprehensible to the average car owner.

The TCU itself is roughly the size and weight of a paperback book. It's designed with heat and vibration shielding, so it could be mounted anywhere theoretically, including in the engine compartment. Exact positioning depends on the model of car. Hughes has not released any details on the operating system or specific architecture of the unit, although Hughes Telematics President Erik Goldman reported that the processing power would be "in the 500 megahertz (MHz) range," similar to the ARM11 chips used in other automotive applications. Hughes has announced partnerships with IBM and Oracle, who were involved in developing the hardware and software used in the TCU and in user interface systems . It will carry on-board RAM and was designed with flexibility in mind. Via Bluetooth or possibly a USB port, the device will be able to interface with "virtually every form of human machine," according to Goldman.

Telematics Network Technology

Gathering information from the CAN-bus is a great way to stay informed, but the information is more or less useless unless the user can somehow access that data. Hughes accomplishes this by employing a number of methods, including using four concentric circles of communication. The first circle is Bluetooth connectivity, which allows someone inside the car to interface with the system by using a cell phone or other Bluetooth enabled device, such as a Blackberry. The second circle is a two-way cell link that allows the vehicle to send information to the Hughes network. This type of connection permits the network to send information to the vehicle. Hughes is working with several cell providers, but has not yet named their partners. Second-generation Hughes systems will incorporate true 3G broadband features. Cell data is transmitted with a high-gain antenna mounted on top of the vehicle, usually near the rear window. The third circle is actually a WiFi network connection. This means that the vehicle can act as a mini WiFi hot spot, and at certain times, it can link with a network at the user's home -- when it's parked in the garage, for example, allowing information to be uploaded into the vehicle. The user could load a series of street maps, favorite songs and even a few videos to watch on a long trip, for example, or configure automatic daily uploads of traffic and weather information.

The fourth circle is hypothetical at this point. In the future, Hughes plans to create a satellite network that will allow the telematics system to operate anywhere and at all times. Anyone who has ever gone camping or traveled in a city with lots of tall buildings with a cell phone knows that cell coverage is not 100 percent perfect. Satellite communication will help to increase that reliability. Hughes will not actually launch their own satellites -- they'll lease space on next-gen telecommunications satellites that offer higher power return feeds, so that satellite communication will be truly two-way.

Telematics Security

There will be several ways for users to interact with the Hughes Telematics system. Hughes has put a lot of development time into voice recognition software -- in fact, all in-car aspects of the system can be activated hands-free by simply speaking in a natural, conversational manner. This feature also allows new users to immediately start working with the system without having to read any technical manuals. In addition to voice recognition, Hughes also has a text-to-voice system that will interpret e-mail messages and read them aloud. The user can then compose and send an e-mail using just voice commands.

One of the more innovative aspects of the system is the ability to interface via a Web portal. A secure website hosted by Hughes Telematics will allow users to log in and check the diagnostics of their car, set up daily uploads via the WiFi network or subscribe to new services. Company president Erik Goldman envisions telematics as a way to integrate your car into your life in new and exciting ways. "Telematics isn't just a safety feature, it can be something you experience every day," he said.

Indeed, this philosophy is tied to Hughes Telematics' business model. Current telematics systems are linked to a subscription service. If the user stops paying for the subscription, he or she loses access to all of the system's features. Hughes will follow more of an à la carte model that allows for impulse purchases and micropayments. For example, users might not want to pay a monthly fee for access to local info and telematics navigation. However, if they travel out of town and find themselves looking for a restaurant, they might be willing to pay a one-time fee to access the service. Goldman gave another example: "Let's say you hear a song you like on the radio -- using voice commands, you can immediately purchase that song from iTunes."

Some features will be subscription based, but users will be able to choose exactly what they need. Goldman gave the example of a father who gives his daughter the car to use while she's away at college. He can use the Web interface to set up maintenance reminders and even configure a "geo-fence" using the on-board GPS to make sure his daughter doesn't drive out of state. The average user might not want these features, and even the fictional father in this example won't need them during the summer months, when his daughter returns from school.

The customization options don't end there, however. Development cycles for automotive technology can take years, but Hughes is developing a flexible mobile telematics system that can adapt to new applications as users demand them. It might work in a way similar to the iPhone App Store. Third-party developers could create software packages that take advantage of the telematics system. Once approved by Hughes, the apps will be made available for purchase by the users, who can pick and choose the applications they like.

The Ego Flash

The Ego Flash is a full-featured, hands-free cell phone device that mounts to your vehicle's dashboard.

Over the last few years you've probably gotten pretty attached to your cell phone. And sometimes there are phone calls that you just have to make, even if you're driving a car when you have to make them. But you also know that using a cell phone while you're at the wheel of your car is dangerous. Many states have banned it outright. So, if you need to make a call while driving and you don't want to (or can't) pull into a parking lot, what can you do?

A lot of newer cars come with hands-free cell phone devices installed, but if your car doesn't have one of these, the Ego Flash from Funkwerk Americas, Inc. may be what you need. The Ego Flash is a full-featured hands-free device that works with Bluetooth-enabled phones to let you carry on conversations while keeping your hands on the wheel as much as possible. Like most aftermarket automotive gadgets, you can have it installed professionally or you can install it yourself. Once in place, you can use it much the same way you use your Bluetooth phone, except that now you can leave the phone in your pocket.

A microphone mounted near your dashboard picks up your voice and you hear the voice of the person at the other end of the line coming through your car's audio system, so it's not much different from talking to somebody in the passenger's seat. And if there's nobody you want to talk to at the moment, you can use it to listen to music stored on your cell phone or your Bluetooth-enabled MP3 player. It also has an iPod controller, but this is only available if you purchase the optional Ego iDapter kit. ­The Ego Flash is easy to set up and easy to use. Over the next couple of pages, we'll look at some of the features offered by the Ego Flash and see just how simple these gadgets really are.

Functions of the Ego Flash

The Ego Flash is about as full-featured a hands-free device as you could ask for. A lot of the things the Ego Flash can do for you are the same things your cell phone can do, but it does them in a way that's not distracting while you're driving a car. For instance, it has caller ID, automatic redial, and a phonebook filled with numbers for your contacts. It can also do some things that your cell phone probably can't. For instance, if you have a Bluetooth-enabled MP3 player or MP3 music on your cell phone, the Ego Flash can play it through your car's audio system. As we mentioned on the previous page, it also has an iPod controller built-in and a cable to connect an iPod with the unit.

The following are just a few of the many functions of the Ego Flash:

• Built-in directory of phone numbers
• Voice controls
• MP3 player for Bluetooth-enabled MP3 devices
• Apple iPod controller (with the Ego iDapter kit)
• A 1.6-inch organic light-emitting diode (OLED) display
• Caller ID
• Reads text messages out loud
• Digital signal processing (DSP) noise-cancellation technology
• Phonebook download

The voice controls make it possible to use many of the Ego Flash's functions with minimal use of your hands. For instance, to dial the number for Fred Phillips, you just have to press the Ego Flash button that activates voice control and say, "Call Fred Phillips." Or you can be even more specific and say, "Call Fred Phillips at home" or "Call Fred Phillips at work." Of course, this assumes that Fred's number is already stored in the phone's directory. If it's not, you can say "Dial number." The Ego Flash will then prompt you for the number you want to dial and you can say the individual digits. It even has commands that allow you to correct the number in case you make a mistake.

The software in the Ego Flash will almost certainly be revised in the future and it's even possible that new features will be added, so new software can be uploaded to the Ego Flash via its Bluetooth connection.

Using the Ego Flash

The Ego Flash can be programmed to recognize up to 10 different cell phones.

Installing the Ego Flash is fairly easy; in fact, it's probably easier than most aftermarket automotive gadgets. The Ego Flash consists of three parts -- the control unit, the electronics box and the microphone. The electronics box is the bulkiest of these parts, because it's where most of the heavy electronic "lifting" goes on. It doesn't have to be in physical contact with either the control unit or the microphone, so you have some leeway in deciding where you're going to place it. However, because the electronics box has the Bluetooth antenna in it, it's important that the front of the box not be blocked by anything metallic or even by plastic panels with some metallic content. This means you can't just shove it in the glove compartment and forget about it. You can't put it behind the dashboard, either. A good place to mount the electronics box is underneath the dashboard on either the driver's or passenger's side. Installation kits for most makes and models should be available from the dealer who sold you the Ego Flash.

The control unit, meanwhile, is where the user controls are, so it needs to go somewhere that's easily accessible from the driver's seat. It comes with an adhesive pad so it can be attached to any available surface. The microphone also comes with an adhesive mounting pad; the manufacturer recommends that it be placed either behind the steering wheel or on the A-pillar between the side window and the windshield. Mounting it on the window is illegal because it may block your vision.

After installation, the Ego Flash needs to be programmed to recognize your cell phone. It can be programmed to recognize up to 10 different cell phones, so every member of your family can use it. Voice commands can be activated by pressing a button on the control unit. Instructions for doing all this are available in the Quick Guide and User Manual that comes with the Ego Flash. Names and phone numbers can be entered into the Ego Flash's directory using a built-in program called the Speller, which allows you select numbers, letters and groups of letters using the keys on the control unit.

Once set up is complete, using the Ego Flash is easy. It can be controlled via voice or the keys on the control unit. Now you're ready to start making phone calls. The Ego Flash will alert you to incoming calls using the same ringtone that your phone uses, but now the ringtone will come through your car's audio system. The Ego Flash also has ringtones of its own you can select, if you choose. The phone number for the incoming call will appear on the control unit's LED display. To accept the call, just press a button. Whatever you're listening to through your vehicle's audio system will be muted automatically and replaced by the call's audio. Making an outgoing call isn't much more difficult. You simply select the name of the person or business you want to call using the Ego Flash controls and press a button to call them, much as you would on your cell phone. Or you press the Ego Flash button that activates voice control and select the party you want to call without using your hands.

As briefly mentioned earlier, the Ego Flash also comes with an iPod controller if you purchase the optional Ego iDapter kit. With this kit, you can connect your iPod via a cable that comes with the iDapter (the cable also serves as an iPod charger) and control it with the Ego Flash's buttons and on-screen menus. When you're driving, these larger controls are much easier to use than are the iPod's normal controls.

Sirius Backseat TV

They're behaving for now, but how do you keep them entertained?

Parents have developed lots of ways to get their young offspring to behave on long road trips over the years.

­­There's the electronic isolation approach: Give each kid a handheld game system and allow them to destroy simulated villains rather than their siblings. Closely related is the in-car DVD approach, which only works if the front-seaters can handle the aural assault of multiple kiddie shows. Of course, there's always the peace by intimidation method: "Don't make me have to stop this car and come back there!"

Satellite programming company Sirius XM Radio, Inc. says it has another way to promote backseat bliss for the younger crowd. Its Sirius Backseat TV pipes kid-friendly television channels like Nickelodeon, Cartoon Network and The Disney Channel into the rear seat video monitors of properly equipped vehicles.

­What's more, grown-ups in the front can separately listen to more adult fare while the kids watch and listen to their own programming. It's possible because Sirius fits the television channels within the digital bandwidth that carries the rest of its programming. Consider it one more way in which consumer electronics companies are making entertainment increasingly mobile.

­This article examines the ins and outs of Sirius Backseat TV -- what it is, how it works and how it blurs the distinction between home and mobile video. In order to get programmed television shows in your vehicle, you once needed a bulky satellite receiver on your car's roof, or you could try to receive over-the-air signals with a portable television.

What is Sirius Backseat TV?

The Chrysler 300 shown here is one of the cars that features Sirius Backseat TV.

Sirius makes its appeal to parents by summoning a refrain they should know very well: "Never again be asked, 'are we there yet?'"

Like a high-tech, electronic nanny, Sirius Backseat TV offers to keep the kids pacified and occupied while they're being ferried about in their parents' vehicle.

What is Sirius Backseat TV, anyway? Simply put, it's a mobile entertainment service that consists of Sirius tuning hardware and a monthly subscription for the programming. For the moment, it's available as an installed option exclusively on new Chrysler, Dodge and Jeep vehicles. It'll set you back $470 for the receiver and the first year of service, and it's available on these vehicles:

• Dodge Grand Caravan
• Dodge Charger­­
• Dodge Magnum
• Chrysler Town & Country
• Chrysler 300
• Jeep Commander
• Jeep Grand Cherokee

­But if you're not buying a new Chrysler, Dodge or Jeep, you can also have it installed as an aftermarket option, similar to a custom car stereo system. As an aftermarket option, Sirius refers to the product as the Sirius Connect Audio/Video Tuner (SCV1). If you buy the unit separately to mount in a car you already own, it'll cost you about $300, plus a $6.99 monthly subscription fee and the normal $12.95 monthly Sirius satellite radio subscription, which you must have in order to get the satellite television service.

You must supply the backseat monitor (or monitors) yourself, and, like Sirius radio, the system can be integrated with your existing car radio and DVD player.

The system includes two small antennae that are installed on the roof of your car, and the TV channels are squeezed into the same swath of spectrum bandwidth as Sirius' 130 radio channels. The video quality has generally received good marks from reviewers -- you won't mistake it for HD, but users report they see none of the lag or pixilated imaging that has plagued some mobile video services in the past.

Like other satellite-dependent entertainment systems, Sirius broadcasts can fade out in inclement weather or when the vehicle is near obstructions like tall buildings or tunnels. That's because these disturbances keep the satellite signal from reaching your antenna or dish. Satellite industry suppliers are constantly developing equipment to decrease the weather's impact on your signal, known as "rain fade" .

Backseat TV comes with a child-friendly wired remote control that lets backseat viewers select between channels. People in the front seat also get a wired remote they can use to select their own Sirius radio programs.

The Backseat TV programming itself is television that incorporates shows from Nickelodeon, The Disney Channel and Cartoon Network. Nickelodeon and The Disney Channel feature round-the-clock airings of their full-length shows, including SpongeBob SquarePants, Dora the Explorer, Hannah Montana and Cory in the House. The Cartoon Network offerings are much shorter and are packaged into a sub-brand called Cartoon Network Mobile. Instead of full-length shows, this network runs short-form programming that includes two- to 11-minute clips from shows like Chowder, My Gym Partner's a Monkey and Foster's Home for Imaginary Friends.

Watching TV in the Backseat

Come on, admit it: There's just something mesmerizing about pulling up on another car's rear quarter and peering into the blue glow of LCD screens inside. Your first thought is probably, "What are they watching?"

Entertainment
The driver of this tricked-out truck ought to keep an eye out for cops on the highway.

Could ­­that voyeuristic instinct become a safety hazard if drivers everywhere start installing video units? Sirius almost seemed poised for the legal backlash by purposefully naming its product Backse­at TV. Sirius knew what it was doing: Many states have passed laws forbidding front-seat video viewing, for safety's sake. Lawmakers and electronics manufacturers compromised; the tech companies agreed to disable the front seat car stereo's video capabilities if the vehicle's emergency brake is disengaged. In other words, the video will only play in the front seat when the vehicle is in park and the parking brake is applied.

Of course, inventive enthusiasts have created all kinds of hacks and workarounds to circumvent this safety feature. However, police officers can -- and do -- issue tickets for front-seat monitors that they see playing while someone's driving. However, you can install as many back seat video screens as you please.

­Apparently, lawmakers feel the risks posed by a driver viewing someone else's car video programming are acceptable, but the research literature is somewhat fuzzy on this point. Numerous studies point to the risks of distracted driving, but no one can pinpoint the exact number of auto accidents caused by consumer electronics. In recent years, public officials have focused specifically on conducting cell phone conversations and texting while driving. "The more devices you have in a vehicle, the more potential distractions you have," said Ron Kipling, a specialist in human factors in traffic safety for the Virginia Tech Transportation Institute . That said, wouldn't a device that reduces the distraction of screaming children in the back seat benefit a driver's concentration? Perhaps the proliferation of cell phones with streaming video and better live television offerings to drivers will produce more research on the relationship between the small screen and driver safety.

Can someone with minimal electronics skills rig a monitor to play Backseat TV up front? Sure, but common sense should prevail to ensure that you don't have videos playing where they will distract you and endanger others on the road.

Sirius Backseat TV Costs

­

Despite the severity of the current economic downturn, analysts predict the mobile communications industry to continue its exponential growth.

One thought might occur to an adult considering this product: Does it make sense to spend so much money to avoid speaking to the kids on road trips? Will anyone buy this?

Keep in mind that this product currently costs at least three hundred bucks up front, plus $20 a month for the subscription. It's not exactly cheap, especially when you consider that conversation is free. On the other hand, part of that subscription price includes access to Sirius audio channels.

Mobile reception systems for satellite television provider DirecTV have been available for years, but their bulk (appropriate only for SUVs, RVs or vans and not passenger cars) and expense ($1,500 or more) have sharply limited their appeal.

From a business perspective, Sirius is doing what any forward-thinking subscription media service should do. They're using technology to search for ways to reach new customers and expand revenue. Cable TV companies, phone companies and satellite programming providers all aim to increase what they call average revenue per unit (ARPU). ARPU is a measurement -- specifically, total product revenue divided by the total number of product subscribers -- used by communications companies to track a product's popularity and growth. They can increase ARPU by raising rates and aggravating customers, or they can do it by adding services and charging a bit more for them.

What's unknown at this point is how consumers will respond, given the rapid changes occurring in the marketplace. Streaming video to cell phones has gained more visibility in the United States with services such as Verizon's V-Cast and Sprint's Sprint TV. At the same time, the financial crisis that boiled over in 2008 threatens to dull consumer appetites for non-essential expenses for some time.

There hasn't been an immediate rush by U.S. consumers to embrace mobile live television offerings like Backseat TV, but analysts expect that to change. The United States has typically lagged behind places like Japan and Europe when it comes to mobile communications -- more evolved cell phone networks in these regions have permitted quality streaming video since the early 2000s. "It's just a matter of time" before the mobile video lifestyle becomes popular, telecom analyst Jeff Kagan told U.S. News & World Report .

­

­For now at least, Sirius considers Backseat TV an ancillary service, or something that's not a primary contributor to its bottom line. However, as mobile video gains wider consumer acceptance in the United States, it would be short-sighted to predict the "small screen" sector will remain small.

In-dash Night-vision Systems

BMW's Night Vision with Pedestrian Detection system allows drivers to see what (or who) is down the road -- even on the darkest nights.

How many cool movies have you seen where a secret agent drives an exotic car through the mountains without any headlights? Or a low-flying AH-64 Apache pilot who moves in for a kill in pitch blackness? What about the urban legend of the 200-mile per hour (322 kilometers per hour) Lamborghini used from making covert drug runs at night, all the while escaping detection under a blanket of darkness? All of these images stem from the concept of night vision.

Perhaps the most common application for night vision is military. Soldiers like the one flying the Apache rely on night vision goggles as much as they rely on weapons and training. In short, night vision brings daylight to darkness. Pilot vision, rifle vision for soldiers and even driver vision are all cutting-edge applications for night vision technologies.

In this article, we'll look at night vision systems found in production cars. We won't be busting the case on the mythical Lamborghini, but you will understand how two of the leading manufacturers in the auto industry are taking back the night in attempt to make driving in the dark safer. In recent years, multiple studies have been conducted in the United States as well as Europe and they all seem to paint the same general picture: The majority of driving is done with the aid of daylight, yet a high volume of fatal accidents occur at night.

­If you've ever driven on a desolate road outside of the city and seen a deer or other type of nocturnal animal flash across your headlights, then you know just how poor night visibility can be. Wouldn't it be nice if you could see what's up ahead, or even alongside the road while driving after sundown? The individual brain-trusts at BMW, Mercedes, Toyota and General Motors think that would be a good idea, too. That's why each has taken a crack at developing night vision systems.

What is night vision?

The human eye can see images which reflect light from violet to red in the electromagnetic color spectrum. Beyond the visible spectrum for humans is the light known as short-wave infrared, light. The human eye is unable to see that light. Short-wave infrared light is a term that actually encompasses all infrared light, but can be broken down into subcategories.

Infrared light actually falls into three classifications: near-infrared (near-IR or NIR), mid-infrared (mid-IR or MIR) and far-infrared (far-IR or FIR), also known as thermal-infrared. The difference between the three types of infrared light comes down to wavelengths. Near-IR, or NIR, has the shortest wavelength -- smaller than 1.5 microns -- and is closest to what we as humans can see as visible light. Far-IR, or FIR, is quite different. Thermal infrared wavelengths can be up to 30 microns and FIR is emitted from an object rather than reflected. In other words, FIR gives off thermal signatures while the other two types of infrared radiation do not.

The two main methods of night vision are thermal imaging and photon detection or image enhancing. Both are used regularly and both have their own advantages and drawbacks. Thermal imaging isn't quite as clear, but it is especially effective for picking up heat signatures. For instance, a soldier looking through a set of thermal imaging night-vision goggles would be able to spot an enemy that is hiding behind a bush or another object that gives off a colder signal. Unfortunately, the bright image could also be a friendly troop. Thermal imaging simply isn't clear enough to show that kind of detail.

Image enhancement on the other hand is very clear. Perhaps you've seen an example of imaging enhancement night vision on a news broadcast or military show. Oftentimes the picture is green, but other than that, the visual is clear as day. Image enhancing takes protons from ambient light and converts them into electrons. These electrons are then chemically and electrically converted into images that appear to be similar to watching an old black-and-white movie.

Car Night Vision History

Siemens System with HUD Taking your eyes off the road while you're driving is never a good idea -- especially at night. That's why Siemens is in the process of developing a night-vision system that projects the images in a heads-up display (HUD) arrangement. Similar to those found in the cockpit of an F-16 Fighting Falcon, a HUD night-vision system would certainly seem to be a safe alternative to looking at a remotely positioned display screen. However, the HUD does have some drawbacks. Having a display in front of a driver can also prove to be distracting. While no system seems to be perfect, the fact remains that night-vision technology is on the cusp of availability and very well could be the next must-have gadget for your car.

In 2000, General Motors offered a thermal night-vision system in its Cadillac line of vehicles. The system was innovative, but it was also expensive and didn't produce very clear images. Toyota also gave night vision a shot, and even now the automaker continues to offer an in-dash system in some Lexus models. The Lexus system has its fans, but if it's so effective, then why hasn't this technology spread to every vehicle on the road? One theory is that it seems as if the technology just isn't fully ready for automotive applications. Not yet, anyway. As you can imagine, night-vision technology is expensive and if you use inexpensive components, the quality simply won't be there.

Two of Germany's automotive stalwarts, BMW and Mercedes-Benz, have taken a damn-the-torpedoes approach to in-dash night-vision systems. These two auto manufacturers have been offering night-vision systems in vehicles since 2006. Fittingly, the two automakers, which have been competing against each other in the luxury market for the better part of 50 years, offer systems on complete opposite ends of the proverbial spectrum. Each system accomplishes its goal and each has its benefits and costs.

Car Night Vision Systems

The Mercedes-Benz Night View Assist system is an example of near-infrared (NIR) technology.

As you might imagine, the two auto moguls get from point A to point B in entirely separate ways. Mercedes-Benz uses an active system or near-IR system that illuminates the night with projected infrared light, much like optics found in military-issue night-vision goggles. BMW's passive system, on the other hand, uses far-IR or FIR technology in its onboard night-vision systems.

Unlike night-vision optics used for military applications, BMW's system registers images based on body heat and produces images that resemble a photo negative. While that works well for deciphering between animals and people, it doesn't do much for revealing a dead animal in the middle of the road or perhaps a large rock or a fallen tree. BMW's infrared system uses complementary metal oxide semiconductor (CMOS)-based sensors on the front of the car that pick up heat from objects and processes the thermal signature to display images on a quarter video graphics array (QVGA) display (320x240-pixel resolution) mounted on the dash in the center of the vehicle's console. In a nutshell, the BMW's system picks up the heat of the animal or pedestrian and displays it as a bright image. The warmer the target, the brighter the image displays. It has a range of around 980 feet (299 meters) and can pan in the direction the vehicle is heading. The FIR night vision system illuminates what's directly in front of the vehicle reasonably well, but doesn't offer the clarity found in the Mercedes system.

In contrast, the Mercedes system uses NIR technology and produces an even, clear picture in the dark. This system is similar to night-vision goggles soldiers use. Like the military-issued night-vision goggles, the NIR system in the Mercedes illuminates everything as if it were in the high beams of the vehicle. By utilizing a series of projection bulbs and cameras, the Mercedes' active night-vision system picks up the faintest traces of light and transforms it into a clear picture. The advantage is that the Mercedes system can see warmer living things just as clear as it can spot colder, dead animals or non-living objects. The drawback to the Mercedes system is its range: The system has a maximum effective range of less than 600 feet (183 meters). Another drawback is the Mercedes' NIR system doesn't handle fog well, while the BMW's FIR system can see through the dense conditions. But unlike the BMW's system, the Mercedes monitor is located behind the steering wheel, directly in the driver's line of sight to the road, and the image quality is also crisper on the NIR system.

Both systems can be turned on or off by the driver with controls found near the high-beam lever and neither system is affected by oncoming bright lights. Both are easy on the eyes too, so sensitivity to light should not be a problem for most drivers. Researchers from the two companies are also in the process of perfecting warning indicators on the night-vision systems. The challenge is to be able to decipher what's a hazard and what's merely a heat signature. The goal is for the systems to be able to set off an alarm when a pedestrian or animal is close enough to the road to be hazardous.

Both systems cost an extra $2,000 to $2,500. While that may sound like a significant amount of money, when you look at the price tag of a 7-Series BMW or S-Class Mercedes, two vehicles that can easily top $100,000, it somehow seems a bit more reasonable -- especially when you consider the benefit of being able to see through the darkness.

Headrest Monitors

The Audiovox FLO/TV seatback television system is pictured during the International Consumer Electronics Show (CES), Wednesday, Jan. 7, 2009 in Las Vegas, Nev.

In-car video entertainment. For those of us who spent our childhood on road trips, crammed in the back of a station wagon with nothing to do but punch our brothers or sisters, it seems like a godsend. For the parents who were trapped in the same car with three kids who decided to pass the time by punching, pinching and asking, "Are we there yet?" it seems like nirvana. But for today's kids, it's becoming par for the course.

With technology shrinking, drivers are no longer dependent on their radios to entertain passengers. Cars and trucks can now be outfitted with VCRs, DVD players and even the latest video game systems. While the entertainment systems' range includes everything from basic portable DVD players to large ceiling-mounted viewing screens, the most luxurious viewing option for many car passengers is headrest monitors. With headrest monitors, each passenger has a personal monitor mounted on the back of the headrest of the seat directly in front of them. Not only do personal monitors of this sort cut down on issues like sun glare, but in some systems, each monitor can display different programming (ending fights over what to watch) or even use different entertainment devices. That means that while one passenger watches a DVD, another can play video games.

Of course, there are some downsides to built-in headrest monitors.
The systems tend to be very expensive. While some manufacturers offer the systems straight from the factory, they can add thousands of dollars to the price of a car. Actually, only a few luxury car manufacturers currently offer factory-installed headrest monitors -- making them an expensive addition to an already expensive purchase. Aftermarket headrest monitors are more common, but these are still an expensive proposition and usually require professional installation.

­­But, if it's headrest monitors you want, we've got you covered. So buckle up, quit bothering your sister and if you ask to stop at McDonald's one more time, we're turning this HowStuffWorks.com article right around and no one will learn anything about headrest monitors.

Factory and Aftermarket Headrest Monitors

If you're in the market for a new car, you've got a lot of factory-installed entertainment options. Selecting a factory-installed system makes providing entertainment for your passengers easy. The system is set up and ready to go from the moment you own the car. You'll have a warranty for all of the entertainment system's parts and even the labor required to install them. You'll also know that all the components have been designed to work with your car, and they'll fit seamlessly into the design and operation of the vehicle.

For those with their hearts set on factory-installed headrest monitors, you're choices are more narrow than if you considered other factory-installed in-car entertainment systems. Currently, only a few luxury carmakers offer factory-installed headrest monitors on their cars. For those in the new car market who want this feature, you'll have to limit your car shopping to luxury SUVs and crossovers. Some sedans do offer the monitors; however, they tend to be extreme-luxury sedans like Maybachs. Even at the mere luxury level, a factory-installed system will set you back quite a bit. For example, the Land Rover optional headrest monitor package adds around $2,500 to the vehicle's price.

Aftermarket systems can be more affordable. For one, you don't have to buy a new car to get them. The headrest monitors alone are really not that expensive. Seven-inch (17.8-centimeter) monitors start at around $80. However, mounting these monitors can be very complex. You have to cut into the back of the headrest, run the wires into the seats and route them to the input device (VCR, DVD player or game system). And don't forget that you have to put the seat back together again. That's something that's out of the league of many do-it-yourselfers, which means installation costs need to be added to the relatively low price of some of these stand-alone headrest monitors.

A less labor-intensive option is to replace your car's headrests with headrests that have monitors pre-mounted. Many car audio suppliers manufacture these, and installation is as easy as popping your old headrest off, putting the new one on and running the wires to the input device. A set of two of these ready-to-go headrests can cost upwards of $800. Some even hide a DVD player behind the screens, which folds out of the way to change disks. That makes installation even easier since you don't have to run additional wiring to a remote device.

Headrest Monitor Sizes and Limitations

When it comes to the size of a headrest monitor, you're only limited by the size of your vehicle's headrests. However, because of the visibility needs that arise from the fact that these systems are in a car, most headrest monitor viewing screens top out at around 10 inches (25.4 centimeters). If you want a larger screen, you're likely going to have to consider a ceiling-mounted video monitor.

One of the reasons that many people want headrest video monitors is so their passengers can choose their own entertainment. However, just because a car has headrest monitors does not mean that each monitor is capable of playing unique programming. For instance, if you have two kids and one wants to watch the Jonas Brothers while the other wants to watch Spongebob, your system will need to meet some specific requirements.

First, you're going to need more than one DVD player. It's very important to distinguish between scenarios where you'll require more than one player and simply a DVD changer. A DVD changer is a DVD player that holds multiple DVDs in reserve, but can only play one at a time. To play two different DVDs, you'll need either two players (perhaps mounted in the headrest behind each screen) or a DVD player that's capable of playing both DVDs at the same time. Make sure you know what kind of setup you're opting for.

You'll also want to investigate the audio options for your in-car media. One of the benefits of in-car DVD and video is that it can effectively end your kids complaining about how old your choice of music is. Unless you want to listen to everything your passengers watch (which can be very distracting), you'll need to check out your audio options. Some in-car DVD players play the audio through the car's stereo system, subjecting everyone to the same sounds. Others allow passengers to plug headphones into jacks near their seats to select the audio they choose. In this scenario, the audio the driver selects is played over the car's stereo. Still others have wireless headphones that allow passengers to choose their audio. When buying a factory or aftermarket headrest monitor system, be sure you know what your audio options are.

Headrest Monitor Setup

Want More? Have you decided that watching DVDs and playing video games is simply not enough in-car entertainment for you? Check out cars from BMW and Chrysler -- both automakers have announced they are putting WiFi in some of their models.

While a number of factory and aftermarket headrest monitors have a DVD player in the headrest, behind the screen -- remember, the screen slides out of the way to access the player -- there are a number of other system options. While the headrest monitor and DVD player combo may be the easiest to install, it also has some limitations. In many cases, it means that both headrests can't watch the same DVD. These systems also make it difficult for the monitors to show other media, like video games.

It may seem like a small point, but where the media players are located is actually pretty important. Some factory systems place the DVD player (or players) in the dash, making it relatively simple for the driver or front passenger to load discs for the passengers. Other factory systems place the DVD player in the rear cargo area. That allows for a lot of different types of media in the car. A large DVD changer can fit, and so can one (or more) video game systems. However, this placement has its downsides, too. It can't be safely accessed while the car is in motion. Also, if there's cargo in the cargo area, access to the media may be further limited. Plus, running the wires from the monitors through the vehicle and into the cargo area also complicates installation for aftermarket systems.

Other systems put the media between the front seats, facing the rear seat passengers. That allows for the back seat passengers to access the media players to change discs or games. On the other hand, such placement puts the media players at risk for getting kicked or stepped on as people enter or exit the car, and not every vehicle has enough space between the front two seats for a media player (or two).

The way many headrest monitor manufacturers try to solve these difficulties is by providing wireless remote controls with each monitor. That way, even if the media player is far away from the passenger, they're still able to control it.

Car Headrest Monitors and Gaming Systems

Models show, from left, the Xbox 360 Arcade, the new 60-gigabyte Xbox 360 and the Xbox Elite during a Microsoft press conference in Tokyo Monday, Sept. 1, 2008.

­While being able to watch a movie on the road sounds heavenly to some people who remember road trips with nothing to do but watch the scenery pass, today's cars offer even more entertainment options. One of the most popular is adding video gaming systems to a car's entertainment capabilities.

While no auto manufacturers are adding video games systems to their cars just yet, installing a video game system in your car -- identical to the one you have in your home -- is relatively easy. When it comes to headrest monitors and video game systems, you're limited only by how much you want to spend.

In order to have headrest monitors that can display video games and other types of media, the monitors need to be able to accept more than one media input at a time. Monitors that have multiple media inputs allow the user to switch between media inputs with a remote control.

Merely seeing the game isn't enough -- of course, passengers will want to play the games, too. If the game system is located within the passenger cabin, wired controls should work fine. However, if the game system is located some distance from the passenger seats, wireless controllers are a popular option. In order to make sure the signal from the wireless controllers make it to the game system, you may have to purchase a signal repeater. These repeaters are usually inexpensive and can be easily mounted on the front of the headrest monitor.

Finally, when choosing a video game system for a car, you should keep safety in mind, too. Some games that require a lot of player motion, like some games for the Nintendo Wii, probably aren't the safest choice for in-car play. Just imagine trying to explain to a police officer that you ran off the road because your passengers were having a heated round of Wii Boxing.

Alternatives to Headrest Monitors

So, after reading all of this, you're still not sold on headrest monitors? Well, they are expensive to install compared to other systems, and in fact, they may not work for all cars. But what are your options?

Car headrest and overhead DVD systems by Audiovox are shown at the Consumer Electronics Show (CES) in Las Vegas, Tuesday, Jan. 8, 2008.

­Ceiling-mounted monitors are a popular alternative to headrest monitors. Not only are they offered as factory-installed options on many cars, including several non-luxury cars, but they're less expensive as aftermarket accessories as well. However, the diminished costs often bring some diminished capabilities, too. Though ceiling-mounted monitors are usually larger than headrest monitors, they can only show one type of media at a time. That means that passengers will have to agree on what they choose to watch. Also, the same audio concerns that apply to headrest monitors apply to ceiling monitors. If the driver doesn't want to hear the audio of what passengers are watching, look for a system that offers headphones.

Another alternative to headrest monitors are in-dash monitors, which put a video screen in the car's dashboard. While this setup makes it tough for rear passengers to watch the media, it allows the driver and front passenger to watch media -- something they can't do with ceiling and headrest monitors, both of which are mounted behind the first row of seats. Dash monitors usually combine some entertainment capabilities with navigation or review camera functions. While it's nice that the driver and front passenger can use dash monitors, it has its limitations: The monitor will not display DVD or video game media unless the vehicle is in park. If you drive a manual transmission-equipped vehicle, most systems require you to apply the emergency brake first. This is a safety feature designed to avoid distracting the driver. While other system manufacturers haven't taken the technology quite this far, Mercedes-Benz offers an in-dash monitor with split-screen capabilities. The driver sees the navigation system while the passenger can watch a DVD [source: U.S. News Rankings and Reviews]. Even without the luxury of a split-screen, in-dash monitors are a good option for drivers and passengers who often end up waiting in the car for extended periods of time.

If it seems like in-car entertainment technology has exploded, well, it has. With DVD players, gaming systems, and even WiFi systems, cars and trucks have come a long way from entertaining passengers with only the passing scenery and a scratchy radio. Headrest monitors are just one of several ways to keep your passengers happy.

Exhaust Air Jacks

­
An exhaust air jack would make this job much easier by using the car's exhaust to lift the car up.

If you've ever had to change a tire in the middle of nowhere on the shoulder of a gravelly road, you might consider the exhaust air jack a dream come true. These automotive gadgets make the arduous task of lifting a car off the ground far less painful and awkward -- simply by letting the car's own exhaust do the dirty work.

Traditional portable jacks, like the ones that come with your car, can be intimidating to the uninitiated. They have to be placed at a certain point on the chassis for safety, then fitted with a bar for leverage and cranked up, and up, and up. It takes a bit of strength and a lot of patience -- qualities most drivers find in short supply when a tire goes flat.

­The exhaust air jack lifts a vehicle using emissions coming from the tailpipe. A hose attaches from the exhaust to a big sack placed under the car. The air coming out of the pipe fills the bag, and voilà! The car lifts off the ground.

These gadgets stay inflated for as long as 45 minutes, though you should keep in mind that your car will be idling and using gasoline that entire time. Air jacks come in different sizes and capacities and can lift vehicles as far as 30 inches (76 meters) from the ground. Exhaust jacks deflate in as little as five seconds when the job is finished, and the PVC-coated woven canvas folds up to fit in your trunk until you need it again.

Using Exhaust Air Jacks

Using exhaust air jacks is easier than you may think. They are available in two- or three-ton sizes, and the one for your vehicle depends on how large and heavy it is. No matter how big the vehicle, exhaust jacks lift it up the same way:

• Air jacks come with a hose about 15 feet long. One end attaches to the exhaust pipe and the other to the inflatable sack.
• The sack is placed anywhere under the chassis, so no jack points are necessary. Since the gadget is basically a big balloon, there's no need to center it under a particular spot on the car.
• About 30 seconds later, the exhaust air jack will be inflated and one side of the car will be off the ground. A one-way valve holds the air inside.
• Release the valve to deflate the sack and lower the car.

­

The bottom of the automotive gadget's balloonlike sack is protected from sharp stones, sticks or whatever debris may lurk under your car by a PVC coating. Manufacturers say there's no danger of pressure buildup in the engine because it takes very little pressure to lift the car.

Common uses of exhaust air jacks go beyond changing a tire on the side of the road. They can also be used to lift the front or rear tires so that you can put tire chains on two wheels at once. These automotive gadgets can even be used to lift trailers, boat trailers or basically anything with a frame and a couple of wheels.

You shouldn't do heavy work while underneath a car lifted on an exhaust jack, but, then again, it's not recommended that you crawl under a car lifted on a regular jack, either. Those situations call for a set of ramps or a sturdy floor jack, while emergencies call for a lift you can keep in the trunk, like an air jack.

Other Uses for Exhaust Air Jacks

Instead of calling and waiting for help, the driver of this snowbound car can use an exhaust air jack to get back on the road.

Air jacks were first invented for and used by extreme off-roaders. When a 4x4 is miles from civilization and gets a flat on a rock-strewn incline, a regular jack just isn't going to work. To make matters worse, you're going to have a real problem getting a tow truck out there -- if you can get cell phone reception to call for help in the first place. But tough, inflatable exhaust jacks could get a truck lifted and a tire off the ground anywhere, no matter the surface or the angle of the ground where the vehicle is sitting.

The gadgets that got off-roaders out of trouble now have uses beyond motorists stranded on the side of the highway with a flat tire. Cars stuck in snow, mud, sand or any other surface where tires are spinning instead of grabbing traction can be rescued by using an exhaust air jack rather than waiting for assistance. Drivers in colder climates can avoid getting stranded in inclement weather by using them to quickly install snow chains for extra traction, but keep in mind that snow chains can severely limit the car's maximum speed and fuel efficiency. If you're towing something in a trailer, you can use them to stabilize the cargo in your trailer. Even farmers in tractors stuck out in the back forty can use exhaust air jacks to free themselves and continue working.

­In addition, if you can use these air jacks to change tires, rotating them can be less of a chore (though those stubborn lug nuts are still up to you). As long as you have a running engine with an exhaust pipe and space for the bag under the frame, you'll have a way to use an exhaust air jack.

DC/AC Power Inverters

DC AC Power Inverters
An inverter like this 200-watt unit is easy to use and install. It's very portable, but its best suited for powering small electronic devices.

­Everyone uses some kind of electronic gadget while in their motor-home, SUV or car. You might listen to your MP3 player, check for directions on your global positioning system (GPS) or play a portable video game. These types of electronic devices can be recharged or powered by plugging them into the cigarette lighter (or power port) in your vehicle.

But what if you want to use something a little more elaborate while you're on the open road? Maybe you want to make toast, watch an LCD TV, or perhaps even write an article on your laptop computer. These devices plug into regular wall outlets, not cigarette lighters. Making sure your electronic gear gets the juice it needs while on the road isn't a simple matter of finding the right adapter. You need a power inverter.

­Power inverters convert direct current (DC), the power that comes from a car battery, into alternating current (AC), the kind of power supplied to your home and the power larger electronics need to function. What kind of power inverter is the right one for the job? How do you install one? And how exactly does an inverter change the current from one form to another? In this article, we'll explore all the positives and negatives of DC to AC power inverters.

Why Do I Need To Convert from DC to AC?

Most cars and motor homes derive their power from a 12-volt battery. In some cases, a heavy-duty 24-volt battery might be used. It's important to know your vehicle's voltage because the voltage rating of the inverter you select should match the voltage of the battery. In either case, the battery provides direct current. This means that the current flows continuously from the negative terminal of the battery, through the completed circuit and back to the positive terminal of the battery. The flow is in one direction only, hence the name direct current. The ability to provide direct current power is inherent to the nature of batteries.

Direct current is very useful, but batteries can generally only provide relatively low-voltage DC power. Many devices need more power to function properly than DC can provide. They're designed to run on the 120-volt AC power supplied to homes in the U.S. Alternating current or AC, constantly changes polarity, sending current one way through the circuit, then reversing and sending it the other way. It does this very quickly -- 60 times per second in most U.S. electrical systems. AC power works well at high voltages, and can be "stepped up" in voltage by a transformer more easily than direct current can.

An inverter increases the DC voltage, and then changes it to alternating current before sending it out to power a device. These devices were initially designed to do the opposite -- to convert alternating current into direct current. Since these converters could basically be run in reverse to accomplish the opposite effect, they were called inverters.

Making Direct Current Alternate

This unit provides 1,500 watts of pure sine wave power. The wave is probably better than that provided by your home electrical system, but the manufacturer's price for one of these is almost $1,000.

The earliest AC power inverters were electro-mechanical devices. Direct current would flow down one end of a circuit with an electromagnet. As soon as the current hit the magnet, the magnet would activate. This would pull a wire attached to a spring arm, forcing the wire to contact the circuit. This would change the flow of the current to the other side of the circuit, cutting power from the electromagnet. As soon as the magnet released, the spring would snap the wire back, allowing the current to flow on the other side of the circuit, once again activating the magnet. These old inverters were known for making a buzzing sound.

Modern inverters use oscillator circuits to accomplish the same process. They're made with transistors or semiconductors, so there's no longer the need for a spring arm flipping back and forth to alternate the current.

It's not quite as simple as that, however. Alternating current forms a sine wave. The output of an inverter is a very square wave, not like the smooth, round wave of a perfect sine. Some devices are inherently sensitive to the signal produced by an AC wave. Typically, these are devices that receive or broadcast some kind of signal, such as audio or video equipment, navigation devices or sensitive scientific equipment. You can see or hear the square waveform on a television as lines on the screen or a steady buzz or hum.

Cleaning up the sine wave requires a series of filters, inductors and capacitors. Inexpensive inverters have little or no filtering. The alternating current they produce has a very square wave, which is fine if you just want to make coffee or run something with a simple electric motor. If you need a smoother sine wave, you'll need an inverter with better filtering. Of course, better filtering also costs a little more. Inverters can get extremely expensive, even costing thousands of dollars, that is, if you're looking for an inverter with a smooth sine. The good news: Given a large enough budget, you can purchase an AC power inverter that produces virtually perfect AC sines. In fact, some high-end DC to AC inverters can make sine waves that are even smoother than the AC power supplied to your house.

Watts, Peaks and Surges

The first step in selecting an inverter is to match the inverter to the voltage of the battery you'll be using for power. In the majority of cases, you'll be using a 12-volt battery, so you would want to select a 12-volt inverter.

The next step is to determine which devices you plan to power with the inverter. Look for a label somewhere on each device that tells you the wattage it requires to operate. The wattage rating of your inverter must exceed the total wattage of all the devices you plan to run simultaneously. For instance, if you wanted to run a 600-watt blender and a 600-watt coffee maker at the same time, you'd need an inverter capable of a 1,200-watt output. However, if you knew you would never be making coffee and fruit smoothies at the exact same time, you'd only need a 600-watt inverter.

Unfortunately, things aren't quite that simple. Devices that have electric motors, as well as some televisions, draw a higher wattage than their normal operating wattage rating when they first start up. This is known as peak or surge, and this information should also be listed on the device's label. Most inverters also have a peak rating, so make sure the inverter's peak rating is higher than the peak wattage of the device you intend to power. Microwaves are a special case. As an example, you may know that your microwave is a 500-watt microwave. This is actually the cooking wattage. The power wattage might be twice that amount. Again, check the label on the device to make sure.

If you plan to run your inverter through the cigarette lighter in your car, it's a safe bet that you won't be using any high-wattage devices. In fact, if you try to pass more than about 400 watts through a cigarette lighter connection, it will fail -- and it might even start a fire in your vehicle.

The final specification to look for is the wave output of the inverter. If you'll be powering any of the equipment that is sensitive to square waves, look for an inverter with a "perfect sine" wave output. Be prepared for sticker shock -- a perfect sine inverter can cost almost 10 times as much as the same wattage inverter with a modified sine output. Modified sine means that the current is run through some filtering, so it isn't a square wave, but it isn't totally smooth either.

Inverter Installation

Inverters are very easy to install. Most of them are "plug and play" devices, especially smaller, low-wattage inverters. These inverters have a cable with a plug that fits into the cigarette lighter on your car or truck. They're meant to be portable, so there's no other mounting to be done.

If you have serious power requirements, you might need an inverter like this. It requires a heavy-duty 24-volt battery and has an output of 3,500 watts. You could run almost anything with this, including air-conditioners and other large appliances.

­If you purchase an inverter that allows higher wattages, proper installation becomes a bit more critical. Below 400 watts, the cigarette lighter connection is still a possibility, but wattages above that require direct connection to the battery. The inverter's input cables have clips that can be attached to the terminals of the battery, similar to a set of jumper cables. If the installation is to be permanent, the cables can be bolted to the terminals. The inverter itself can be mounted anywhere, although it should be in a place with good air flow. Inverters generate a fair amount of heat, and they use cooling fans and heat dissipation fins to prevent overheating. Larger, heavier inverters have mounting holes in their chassis so they can be bolted to any surface. Obviously, with a permanent installation, you'll probably want to bolt your converter in place, but this isn't absolutely necessary. It's possible to simply place the inverter in a secure, stable position, clip the leads to the battery and plug in.

Just what does an inverter look like, anyway? Well, the smallest inverters can fit in your pocket, while higher-wattage models are roughly the size and weight of a large dictionary. As a general rule: The higher the wattage, the larger and heavier the inverter. At the top of the inverter wattage scale, some inverters can be more than two feet long and weigh over 30 pounds.

Modern inverters have some built in safety features that make them even easier to use. Some models sound an alarm when the battery's voltage gets too low. This is more of a convenience, but depending on what sort of equipment you're powering, it could also be a valuable safety feature. Inverters typically have automatic shut-off capabilities, too. If the unit detects a current overload or an overheating situation, it will shut down to lessen or prevent the chance of a fire. Inverters can also shut off in the event of a short circuit, such as a piece of metal falling into the chassis or the inverter getting wet. Short circuit shut-off is an effective way to prevent electrocution.

So how much is all of this going to cost, you ask? You can buy a modified sine inverter rated for continuous power of 200 watts for about $25 and the price of a 6,000-watt modified sine inverter can approach $1,000. Pure sine inverters cost much more -- these can be more than $200 for an inverter rated at just 300 watts.

Dashboard Displays

Paradise by the dashboard light.

­"Keep your eyes on the road" has been the mantra of every driver's education teacher and nervous passenger, as well as the occasional rock star (The Doors included the advice in their song "Roadhouse Blues"). But the fact of the matter is, we really don't keep our eyes on the road at all times. And that's not to say that we're engaging in dangerous behavior like texting or changing radio stations while driving -- we're actually briefly averting our eyes to aid the driving experience. We refer of course, to the dashboard display.

The term "dashboard" didn't originate with traffic jams that made drivers want to dash their head against something hard in the hopes of losing consciousness, but instead was passed down to us from the horse and buggy days. Fans of the song "Jingle Bells" have long known that the proper speed for a one-horse open sleigh was "dashing," but when horses started to dash along o'er the fields, bells on bobtails weren't the only things ringing. The cries of the driver and passenger likely also rang out as they got splattered with mud, meaning that spirits were definitely not bright, and laughing all the way wasn't an option. So along came a piece of wood that protected the buggy's passengers from all the mud and slush, which was known as the dashboard.

­When cars replaced carriages, that dashboard came too, as an ordinary slab of wood under the windshield. Dashboard displays, or instrument panels, were a little bit longer in coming. If you needed to know how much gas was left in an early car, you put a stick in your gas tank, and if you wanted to know the temperature, you went to the radiator itself . By the 1930s, though, cars started coming with gauges, and by the mid-30's, all cars included what has been graciously termed the "idiot light," or a warning light indicating that something is wrong with the vehicle . Even in the present day, manufacturers are tinkering with the instrument panel, moving it to the center of the dashboard or packing it full of technology that may make keeping your eyes on the road harder than ever.

Car Dashboard Display

At minimum, your dashboard display has a speedometer and a fuel gauge. In addition to those gauges, the display will feature some combination of a tachometer, charging system gauge, oil pressure gauge and engine temperature gauge. Let's have a quick dashboard confessional that covers what each part does.

The speedometer, one of the most frequently used tools, tells you how fast you're going. You can read more about this bane of a lead foot driver's existence in How Speedometers Work. Traditionally, this gauge relied upon a cable that connected the speedometer to a gear inside the transmission, but now, electric sensors are used with most dashboard devices. Instrument panels basically have a feed of constantly updated information from around the car; in fact, about one-half of a vehicle's total wiring can be found in the dashboard display.

Your fuel gauge can make the difference between a happy ending romantic comedy (the fella has enough gas to make it to the church in time to get the girl) or a scary horror movie (couple runs out of gas near an old abandoned warehouse full of werewolves). If you think your fuel gauge is playing mind games with you, you're right. This gauge deliberately stays on full to three-quarters full for a long time to give you the sense that you're getting good mileage . And of course, as Cosmo Kramer proved beyond a shadow of a doubt on "Seinfeld," you can keep driving once the needle drops below empty -- though only about 1 gallon or so . Fuel up on more knowledge about this instrument at How Fuel Gauges Work.

Running on empty.

If you drive a stick, you're probably well familiar with the tachometer, which measures revolutions per minute (RPM) in the engine. Knowing this information can help you shift at a time when you'll get maximum fuel economy.

Ever needed a jump when your battery went dead? You might have paid more attention to the charging system gauge or warning light afterwards. The amount of electrical current that the charging system provides to your vehicle's battery is monitored by either a voltmeter, which measures the voltage in the charging system, or an ammeter, which measures amperage leaving the battery. When the battery is using too much of its own juice and depleting itself without getting refilled by the charging system, then these gauges or warning lights should alert you to the problem.

While many of us strive to lower our blood pressure, we should never strive to have low oil pressure. The oil pressure gauge measures oil pressure in pounds per square inch, and you're going to have a big problem if that pressure falls in a car. Unless you want to destroy your vehicle, stop the car as soon as possible when this gauge alerts you to a problem; you'll likely be warned via an oil lamp warning light in the dash. Similarly, if your engine gets too hot, you should also get off the road as soon as you can. Your temperature gauge, which measures the temperature of engine coolant, will alert you to a dangerous situation.

There are a host of other warning lights designed to let you know about the status of the car.­ Though there have been some efforts to standardize these lights in all makes and models, they are currently personalized to some extent by car manufacturers. You might see these lights for everything from a reminder that someone's not wearing a seatbelt to a warning that tire pressure is low. For more details about what a certain light is trying to tell you, consult your car's manual.

­The configuration and arrangement of these instruments varies according to each car. In fact, it may surprise you to learn how much time carmakers spend designing dashboard displays.

Dashboard Display Design

First impressions are important, and a dashboard provides your introduction to each automobile you drive. Designers get paid to think about what each person might want from the dashboard, because, unlike with potential partners, you're not likely to ask for a second date with that car if you don't get the information you need upfront. The style, shape and layout of the dashboard can be a deal-breaker when buying a car.

That's why some drivers may have a completely electronic dashboard display, while others still watch the rise and fall of a needle; it seems that young drivers and women, in particular, have more of an affinity for the digital model . Some drivers want as much information as possible about their driving and their car; people with displays that show real-time fuel economy information might make a game out of trying to improve their driving with each mile. The aging baby boomer generation, however, wants basic information in an easy-to-read format .

Miss the good old days? Here's the dashboard display in an antique car.

­The need to control additional technology, from power mirrors to a stereo system, means that dashboard displays will only become more diverse in the future. In 2006, writers at PC Magazine imagined a future dashboard that included drowsiness sensors, advanced navigation systems and voice recognition systems that allow you to ask your car questions. This dashboard of the future will also let you pick which instrument gauges you want to see at a given time and project that display on the windshield, so that less eye movement is required . That means you'll have more time to move your eyes toward the custom entertainment system, full of your favorite music and videos.

That begs the question, of course, as to when a dashboard display becomes a dashboard distraction. Safety advocacy groups worry that drivers will perceive that most of the driving is being done for them with dashboard gadgets such as self-parking devices, lane-change alerts and cruise control. These people will pay less attention to the road and their driving, while even those who are trying to pay attention will be distracted by the constant hum of beeps and the constant flash of notifications from the dashboard. There's a balance to strike multitasking and keeping those eyes on the road.

Dash Express

The Dash Express, the first GPS receiver with two-way connectivity, was released in February 2008.

The idea of using a Global Positioning System (GPS) receiver to many drivers has always been, for the most part, appealing. No matter how well we know some parts of town or memorize all the secret one-way shortcuts through a city, there are times when our spatial reasoning will simply shut down and lead us astray. Most trusty GPS receivers can get us to an unknown location or out of a mess with relative ease by readjusting our route when we get off track or maybe even offering the road less traveled in order to avoid nasty traffic jams.

This is what any typical GPS will do for drivers, and some higher end models will even go the extra mile, providing services that give useful information on restaurants, hotels, movie theaters and other important points of interest for everyday road warriors. Some have even begun to offer entertainment features, such as MP3 player capabilities, Bluetooth connectivity and video.

Despite all of these perks, many think it's time for someone in the car navigation market to reveal the next step on the GPS evolution timeline. If you've paid any attention to the electronics blogs over the past two years, you might believe that Dash Navigation is offering just that. Back in 2006, the company announced the Dash Express, the "first two-way, Internet-connected GPS navigation system." After several years of tweaks and redesigns, the Dash Express was finally released in February 2008, and its makers originally claimed the device would offer two major new innovations to the typical GPS that will render all others "practically obsolete."

­Less than eight months later, however, Dash Navigation surprised the tech industry by announcing that it would end production on the Dash Express, and any hardware associated with it, to focus solely on software development. The company cited difficult economic times and tougher competition from smartphones offering similar technologies. Customers who purchased a Dash Express can still use it as it was meant to be used, and we, of course, can still take a look at what it can do.

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What exactly are the two big features the Dash Express boasts? What are some of the other typical GPS features it offers? What powers the Dash Express? Is it the game-changing GPS the company meant it to be, and how have critics and consumers reacted to it so far? What are Dash Navigation's plans for the future, and could the still influence the GPS market?

Dash Express GPS, GPRS and Wi-Fi

The connectivity features on the Dash Express make it a little more than your typical GPS, which may appeal to those looking for more than just directions.

The main function of the Dash Express is, of course, as a GPS. In this respect, the Dash Express works like most portable car navigation systems -- a GPS chipset receives signals from GPS satellites that orbit the earth in order to determine your car's exact location. The chip then processes the information and displays it onto your GPS screen over a map, helping you determine where you are on the planet. The Dash Express specifically uses a SiRFstarIII chipset, a high-performance satellite signal processor.

The big deal with the Dash Express isn't so much its chipset, but an extra feature that gives drivers more connectivity while they're out on the road. Actually, it's really two features: The Express offers, on top of its typical GPS navigation, Internet connectivity through both Wi-Fi access and GPRS (General Packet Radio Switch).

By now, many people are familiar by now with Wi-Fi -- most laptops and other handheld devices come with built in Wi-Fi capability, allowing them to connect to any nearby network that follows 802.11 wireless standards. The Dash Express's Wi-Fi antenna and receiver connects specifically to 802.11b and 802.11g networks. GPRS, on the other hand, may not be as well known as Wi-Fi, but you may already be using it if you have any handheld devices that surf the Web -- it's a radio technology typically used for cell phones to connect to the Internet.

These two technologies constantly search for networks, keeping drivers connected to the Internet as much as possible while they're in the car. The Dash is synched up specifically with Yahoo! Local search, which can feed drivers up-to-date information on everything from highly rated restaurants, new movies, nearby apartments for rent and the nearest low gas prices.

The Dash's typical approach to ­traffic, what it calls TruTraffic, offers another small innovation -- a constantly updated network of traffic information that acts like a library built by the drivers themselves. The Dash Driver Network automatically (and anonymously) collects driver's routes and sends them to a database. The database can analyze traffic building up in one part of town and notify a driver of congestion in that area. According to its manufacturer, the more people using Dash Express technology on the road, the more information will accumulate, and the more accurate it will become.

Drivers with a Dash Express can also create a MyDash account over the Internet and use the Send2Car feature to send addresses from the home or office directly to the GPS in order to plan ahead. If the Dash Express is on, it should immediately receive the address and plan the route from its current location; if it's off, the address will cache and be resent once you turn the device on.

Dash Express Reviews

Did the initial release of the Dash Express live up to people's expectations?

The Dash Express was one of the most highly anticipated electronic devices of 2008, and one of the most hyped GPS receivers in recent memory. During the Consumer Electronics Show in 2007, where Dash Navigation highlighted the device, it received lots of buzz, and bloggers quickly named it one of the best products of 2008. But how did the Dash Express measure up once the critics got their hands on it?

Nearly every review points out that the Dash Express's major innovation, two-way Internet connectivity via Wi-Fi and cellular networks, is a major plus. The ability to search live for hotels, movies, restaurants and gas stations with the lowest prices while receiving real-time traffic updates from other users gives the Dash Express an advantage over other GPS navigators. Most acknowledge that information will only get better if there are more drivers on the road using the Dash Express.

Despite the excitement, many reviewers pointed out several problems with the Dash Express's performance and design. CNET, Gizmodo, Engadget and several other reviewers noted tracking problems of some kind -- either the Express took too long to update a current map or offered confusing or incorrect routes.

The large size of the Dash Express was universally noted and seen as somewhat of a negative. The device weighs 13.3 ounces (377 grams) and measures 4.8 inches (12.2 centimeters) wide by 4.1 inches (10.4 centimeters) tall by 2.8 inches (7.1 centimeters) deep, much bigger than many of its contemporary GPS units, and many reviewers compared the Dash Express's size to bulkier models made in the 1990s. Dash Navigation has explained, however, that the size of the Express simply had to be large in order to accommodate the wireless radios into the system.

Finally, many reviewers wondered if the initial price of the Dash Express ($400) was too high for a GPS in such an early stage. And although customers get the first three months free, there is a monthly service fee that ranges from $10 to $13 per month.

Although Dash Navigation is stopping production on the Dash Express, that doesn't mean the company is done in the GPS industry. Instead of making the actual hardware, they'll focus on what got everyone excited about the Dash Express in the first place -- developing software for smartphones and GPS devices. Judging by the reaction against the Dash Express's hardware design and the fact that we might find strong Internet connectivity in 62 percent of all navigation devices by 2012, the move may play toward the company's best strengths .