103 Slices
  Title Author Publisher Format Buy Remix
Medium 9781449334765

8. Do LEDs Make Sense Today?

Sal Cangeloso Maker Media, Inc ePub

Whether or not LED bulbs make sense today is a judgment call that every person and business must make for themselves. A higher initial outlay has to be justified against future savings, both in terms of electricity saved and replacement costs. To some, it will seem obvious that LED bulbs are the way to go, while others will be happy to keep buying cheap incandescents as long as they are available. Stepping away from individual judgement calls, do LED bulbs make sense today?

There are three main factors to take into consideration before choosing to go the LED route: initial costs, power savings, and replacement costs. By tabulating these, every person, business, and organization should be able to figure out the the best option for them.

Initial cost is what holds most people and organizations back from buying a more expensive bulb. They see the incandescent bulb that has always worked for them, which is also the least expensive option, and the one that matches the rest of the bulbs they use, so it seems like the obvious solution. As CFL prices dropped, consumers were able to justify the extra expense thanks to their clear labeling about power savings and longer lives, but the mercury warnings have proven enough to turn many people off.

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Medium 9780596007041

9. Do It Yourself

Brett McLaughlin O'Reilly Media ePub

Home theater presents myriad reasons and options for DIY, or do-it-your-self, activities. Reasons can range from and be combinations of saving money, starting a new hobby, meeting particular performance goals, meeting particular appearance goals, the challenge, the satisfaction of the end result, or even just because you're bored on a Saturday afternoon. The formula that will determine if DIY is right for someone will be unique to each person. Actual DIY projects can range from buying a complete kitwhere all you have to do is make a few wire connections and turn a few screwsto designing and building amplifiers.

I'll start with a word of caution. Building audio equipment needs to be a lifetime hobby if you intend to attempt your own designs, especially if you're trying to design a crossover for a speaker or build an amplifier. You won't save money with these activities, and it might take you years to gather all the necessary equipment and learn enough to design and properly implement a speaker or amplifier from scratch.

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Medium 9780596005139

22. Serial Communications

Robert Bruce Thompson O'Reilly Media ePub

In serial communications, bits are transferred between devices one after the other in a series, whence the name. To communicate an eight-bit byte, the transmitting serial device breaks that byte into its component bits and then places those bits sequentially onto the serial communications interface. The receiving interface accepts the incoming bits, stores them temporarily in a buffer until all bits have been received, reassembles the bits into the original byte, and then delivers that byte to the receiving device.

Because any bit is indistinguishable from any other bit, serial interfaces must use some means to keep things synchronized between the transmitting and receiving interfaces. Otherwise, for example, if transmitted bit #4 were lost due to line noise or some other communication problem, the receiving interface would assume when it received bit #5 that that bit was bit #4, resulting in completely scrambled data. Two methods may be used to effect this synchronization:

Synchronous serial communication is so called because the transmitting and receiving interfaces are synchronized to a common clock reference. Because both interfaces always "know what time it is," they are always in step, and always know which bit is on the wire at any particular time. Synchronous serial communication methods are common in mainframe and minicomputer environments, but are little used in PC communications. Synchronous serial communications are normally used in the PC environment only to support specialized devices, which are usually bundled with the appropriate synchronous adapter and cable. Therefore, this book will have no more to say about synchronous serial communication.

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Medium 9780596007041

10. Remote Controls

Brett McLaughlin O'Reilly Media ePub

Imagine the joy of inviting over your closest friends to check out your new home theater system. You've got the expensive sconce lights dimmed, the curtains drawn over your projector screen, and all your gear elegantly tucked away into cabinets that match the wood veneers of your speakers. Your 7.1-channel processor is glowing, and speakers are all around. Your friends sit down, ready to see and hear something special

and they're greeted with the sounds of you fumbling around in a drawer. They begin to snicker as you pull out first one remote, and then another, and then yet another. Ten minutes later, you've managed to get the curtains open and the sound working, but instead of Stargate, the picture on the screen is of a little cartoon girl with her monkey friend, apparently saying something about a backpack. You've been completely embarrassed by the smallest, but arguably the most important, part of your home theater systemthe remote control.

No matter how sophisticated your home theater system is, your remote has to be more so. In fact, as this little anecdote illustrates, your remote better be able to handle everything your system has to offer, without a hitch and without needing a stand because it's huge and unwieldy. Welcome to the world of remote controls.

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Medium 9781449388249

1. Fundamentals

Robert Bruce Thompson Maker Media, Inc ePub

The idea of building their first PC intimidates many people, but theres really nothing to worry about. Building a PC is no more technically challenging than changing the oil in your car or hooking up a DVD player. Compared to assembling one of those connect tab A to slot B toys for the kids, its a breeze.

PC components connect like building blocks. Component sizes, screw threads, mounting hole positions, cable connectors, and so on are mostly standardized, so you neednt worry about whether something will fit. There are minor exceptions, of course. For example, some small cases accept only microATX motherboards and half-height or half-length expansion cards. There are also some important details to pay attention to. You must verify, for example, that the motherboard you intend to use supports the processor you plan to use. But overall, there are few gotchas involved in building a PC. If you follow our advice in the project system chapters, everything will fit and everything will work together.

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Medium 9780596007225

3. Kitchen and Bath

Gordon Meyer O'Reilly Media ePub
Medium 9780596801724

8. Going Green: Transportation and Travel

Nancy Conner O'Reilly Media ePub

Some people say that when you travel, it's not the destination that's important, but the journey. That's also a good way to think about the impact travel has on the environment. Getting from one place to another is one of the biggestand fastest growingsources of greenhouse-gas emissions. According to the U.S. EPA, transportation accounted for 29% of America's greenhouse-gas emissions in 2006, and that's just from cars, planes, and boats moving from place to placeit doesn't include the energy or emissions involved in building vehicles or producing their fuel.

Because transportation is such a big problem for the planet, this chapter helps you become a more responsible traveler. You'll get tips to help you leave your car in the garage or trade it in for a more earth-friendly model. This chapter also explores how to reduce the impact of long-distance travel, whether you're on family vacation or a business junket. Knowing you're traveling in an environmentally responsible way will let you sit back, relax, and enjoy the journey.

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Medium 9780596008666

3. System Maintenance

Robert Bruce Thompson Maker Media, Inc ePub

In This Chapter

Airlines, trucking companies, and other large organizations devote much more time, money, and effort to cleaning and preventative maintenance than they do to repairs. That's because cleaning and regular system maintenance repay their costs many times over by reducing the frequency and cost of repairs. It's almost always cheaper to prevent something from breaking than it is to fix it after it's broken. The same is true for PCs.

Dirt is the main enemy of PCs. Dirt blocks air flow, causing the system to run hotter and less reliably. Dirt acts as thermal insulation, causing components to overheat and thereby shortening their service lives. Dirt causes fans to run faster (and louder) as they attempt to keep the system cool. Dirt worms its way into connectors, increasing electrical resistance and reducing reliability. Dirt corrodes contact surfaces. Dirt is nasty stuff.

Computers become dirty as a natural part of running. Fans suck dust, pet hair, and other contaminants into the case, where they rest on every surface. Even in clean rooms, operating theaters, and other very clean environments, a PC will eventually become dirty. If there's any dust in the air at all, the system fans will suck it in and deposit it inside the case, where it will become a problem sooner or later.

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Medium 9780596007041

5. Speakers and Wiring

Brett McLaughlin O'Reilly Media ePub

It might surprise you that it took five chapters to actually get to the subject of speakers, and even with that, this chapter begins with organization of your racks and gear before jumping into speaker selection. If you're an old home-theater guru, this might not be that odd. But newbies rarely realize that killer speakers without the right gear are just expensive paperweights. Don't get me wrong: the reverse is also true; high-end gear can't put out great sound on its own. However, if you get your components set up and working well, selecting, installing, and testing speakers becomes far, far easier.

In this chapter, you'll get a handle on how to keep your wiring orderly. That rather simple-sounding task turns out to be daunting, and a constant maintenance issue. (If you think it's not a big deal, wait until the first time something goes wrong and you've got to trace a cable through 20 twisted feet of components.) Then I'll dive into speaker selection and really focus on the surround speakers that are so critical to home theater. Finally, you'll learn more than you ever really wanted to know about wiring, from choosing the right kind to using banana connectors to bi-wiring wiring and bi-amping. Get ready for some sound: this is the chapter that makes it happen.

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Medium 9780596005139

19. Keyboards

Robert Bruce Thompson O'Reilly Media ePub

A keyboard is a matrix of individual switches, one per key. Pressing a key closes its switch, generating a signal that the dedicated keyboard controller built into the keyboard recognizes as the make code for that key. Releasing the key opens the switch, which the keyboard controller recognizes as the break code for that key. Using a firmware lookup table, the keyboard controller translates received make code signals to standard scan codes, which it sends via the keyboard buffer to a second keyboard controller located in the PC, which recognizes those scan codes as specific characters and control codes.

Because releasing a key generates a break code, the local keyboard controller can recognize when two keys are pressed together (e.g., Shift-A or Ctrl-C) and generate a unique scan code for each such defined key combination. For undefined key combinations (e.g., pressing "a" and then pressing "s" before releasing "a"), the keyboard controller recognizes that, even though a break code for "a" has not been received, the user's intent is to type "as", and so generates the scan code for "a" followed immediately by the scan code for "s".

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Medium 9780596007225

1. A Foot in the Front Door

Gordon Meyer O'Reilly Media ePub

Getting started with home automation can feel like entering a strange, new world. Familiar things such as light switches and electrical outlets take on new roles and capabilities. You hear about house codes, controllers, and sensors that can tell when someone has entered a dark room. And what in the world is a Powerflash? Before you can create your own smart home, you'll need to educate yourself.

The hacks in this chapter form the foundation upon which you'll build your smart home. Start at the beginning and get the basics of what does what, or dive into the middle and discover something surprising. You'll learn how to turn on lights [Hack #2], take control of your appliances [Hack #3], and find automation equipment that's masquerading at your local hardware store [Hack #23].

But before you get sucked in too far, it's a good idea to prepare both your house [Hack #12] and your housemates [Hack #14] for the adventure upon which you're about to embark. With these hacks in hand, you're sure to get off on the right foot.

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Medium 9780596801724

2. Save Energy, Money, and the Earth

Nancy Conner O'Reilly Media ePub

With utility costs rising and global warming taking its toll, we have more reason than ever to reassess how we use resources. The Alliance to Save Energy estimates that the average U.S. household sends twice as much carbon dioxide into the atmosphere as the average car, so it's important for everyone to cut back their energy use. (Technically, power plants are the ones who spew the CO2, but they do it while producing power for us.) As you learned in the last chapter, you can start fighting pollution right in your own home. Same goes for water and electricity: You can do your part to conserve both by making simple changes around the house.

The first step toward conserving electricityand lowering your utility billsis to examine how you use energy. This chapter shows you how to give your home a checkup to find out. After that, you'll learn all kinds of ways to increase your home's efficiency, including a whole section about heating and cooling systems, which (in an average home) eat up more than half of the energy you pay for each year. Then you'll get info about how much power your appliances use and, if you're shopping for new ones, how to find the most efficient models. You'll learn other great tips for cutting your electricity bill, saving water, and lighting your home, too. Making even a few of the changes suggested in this chapter will put you well on your way to using less energy and helping the planet.

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Medium 9780596007041

7. Connectivity

Brett McLaughlin O'Reilly Media ePub

Understand what makes a good cable, and understand which is the best cable for the job.

The manufacturers include cables with their equipment, but I suggest using these cables only temporarily until you can pick up something of decent quality. I usually recommend the RadioShack Gold Series cables as a good starting point, but you can work you way up to higher-quality cables from there. Before you go out and purchase these cables, though, you need to know what types of cables you require, what they're called, and exactly what they are used for. I'll be describing these cables based on the type of connector used and the actual design of the cable itself.

You'll notice that every cable shown in this section is from Better Cables (http://www.bettercables.com). Although you might choose to go with a lower-end cable, such as ones from RadioShack, I can't recommend Better Cables strongly enough. That company offers amazing cables, at very fair prices, and they are the only kinds of cables I buy for my own system at home.

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Medium 9780596005139

14. Hard Disk Drives

Robert Bruce Thompson O'Reilly Media ePub

All hard disks are constructed similarly. A central spindle supports one or more platters, which are thin, flat, circular objects made of metal or glass, substances chosen because they are rigid and do not expand and contract much as the temperature changes. Each platter has two surfaces, and each surface is coated with a magnetic medium. Most drives have multiple platters mounted concentrically on the spindle, like layers of a cake. The central spindle rotates at several thousand revolutions per minute, rotating the platters in tandem with it.

A small gap separates each platter from its neighbors, which allows a read-write head mounted on an actuator arm to fit between the platters. Each surface has its own read-write head, and those heads "float" on the cushion of air caused by the Bernoulli Effect that results from the rapid rotation of the platter. When a disk is rotating, the heads fly above the surfaces at a distance of only millionths of an inch. The head actuator assembly resembles a comb with its teeth inserted between the platters, and moves all of the heads in tandem radially toward or away from the center of rotation.

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Medium 9780596005139

12. DVD Drives

Robert Bruce Thompson O'Reilly Media ePub

DVD originally stood for Digital Video Disc, later for Digital Versatile Disc (yuck), and now officially stands for nothing at all. DVD is basically CD on steroids. Like a CD, a DVD stores data using tiny pits and lands embossed on a spiral track on an aluminized surface. But where CD-ROM uses a 780 nanometer (nm) infrared laser, DVD uses a 636 nm or 650 nm laser. Shorter wavelengths can resolve smaller pits, which enables pits (and tracks) to be spaced more closely. In conjunction with improved sector formatting, more efficient correction codes, tighter tolerances, and a somewhat larger recording area, this allows a standard DVD disc to store seven times as much dataabout 700 MB for CD-ROM versus about 4.7 GB for DVD.

One significant enhancement of DVD over CD is that DVD does away with the plethora of incompatible CD formats. Every DVD disc uses the same physical file structure, promoted by the Optical Storage Technology Association (OSTA), and called Universal Disc Format (UDF). This common physical format means that, in theory at least, any DVD drive or player can read any file on any DVD disc. Microsoft did not support UDF until Windows 98. This forced DVD content providers to adopt an interim standard called UDF Bridge, which combines UDF and the CD standard ISO-9660. Only Windows 95 OSR2 and later support UDF Bridge, which forced DVD hardware manufacturers to include UDF Bridge support with their hardware in order to support pre-OSR2 Windows 95 versions.

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