Inside the capacitor, the terminals connect to two metal plates separated by a non-conducting substance, or dielectric. You can easily make a capacitor from two pieces of aluminum foil and a piece of paper. It won’t be a particularly good capacitor in terms of its storage capacity, but it will work. In theory, the dielectric […]
Cell-phone Frequencies In the dark ages before cell phones, people who really needed mobile-communications ability installed radio telephones in their cars. In the radio-telephone system, there was one central antenna tower per city, and perhaps 25 channels available on that tower. This central antenna meant that the phone in your car needed a powerful transmitter
Video glasses aren’t a new idea in the high-tech world, in which they’ve been known as a kind of head-mounted display (HMD). They’re also called personal media viewers. No matter what you prefer to dub them, you can’t deny that HMD technology has improved tremendously in the past couple decades. When first widely introduced to
Why Test? Alcohol intoxication is legally defined by the blood alcohol concentration (BAC) level. However, taking a blood sample in the field for later analysis in the laboratory is not practical or efficient for detaining drivers suspected of driving while impaired (DWI) or driving under the influence (DUI). Urine tests for alcohol proved to be
Augmented-reality applications — software that overlays a level of digital information on top of the physical world around us — have brought us more data. With an augmented-reality app on your smartphone, you might be able to hold your phone’s camera up to capture the image of a city street. Looking at the screen, you
Since the 1980s, computer scientists have been trying to answer these questions. Their field is a specialized subset of haptics known as computer haptics. Over the next few pages, we’ll cover how haptic technology works by: relating computer haptics to related fields of haptics research characterizing the types of haptic feedback required for realistic virtual
ere’s a question: What happens when one of the world’s largest electronics companies makes a move to edge its competition out of the top spot in the portable gaming industry? If you’re Nintendo, and Sony has made it clear that it wants to crush you with its new PlayStation Portable, you throw a curve ball
The company was TiVo, the pioneer in commercially-available digital video recorders (DVR). In its 10-year history, TiVo has sold millions of DVRs and service subscriptions. In this article, we’ll look at how the typical set works and the services TiVo provides. Several manufacturers make TiVo sets, including TiVo itself, but they all have one thing
Image enhancement – This works by collecting the tiny amounts of light, including the lower portion of the infrared light spectrum, that are present but may be imperceptible to our eyes, and amplifying it to the point that we can easily observe the image. Thermal imaging – This technology operates by capturing the upper portion
The VCR marks one of the most important events in the history of TV because, for the first time, it gave people control of what they could watch on their TV sets. Prior to the VCR, there was no such thing as a video store, and when you consider that there is now a video
