Sal Cangeloso (11)
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10. The Future

Sal Cangeloso Maker Media, Inc ePub

Its nice to think that the best technology always triumphs, but we know thats not the case. The QWERTY keyboard layout has been maligned for years, yet its so ingrained into our minds (and laptops) that we can be relatively sure its not going anywhere. And, of course, the most often cited example of a better technology being left behind is Betamaxs loss to VHS during the so-called Video Format War of the mid-1970s. Ultimately, its unlikely the LEDs will lose out to another technology, especially incandescents, but it will be a drawn out fight and hard-won victory.

As prices drop and consumer awareness grows, LEDs will flourish. Boosters like the L Prize, government regulation, power company subsidies, and (perhaps) rising energy prices will all assist in LED adoption. The case for increasingly efficient lighting is inarguable, and LEDs have the best chance right now, especially considering the trajectory of the industry and the downward trend of the competition. As power becomes an issue for everyone, awareness will grow and the huge gains in efficiency found in solid-state lighting will be welcomed as the lowest-hanging fruit possible, saving individuals, countries, and the world billions of dollars, not to mention tons of carbon dioxide, a year.

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1. Opening Remarks

Sal Cangeloso Maker Media, Inc ePub

First off, its all about the lumens. Lumens are the visible light given off by a source, and they are the ultimate goal. Wattage has often been confused with lumens, thanks to how incandescent bulbs are rated (everyone knows that a 60W bulb is not as bright as a 100W one), but more efficient lighting technologies have greatly changed the relationship between wattage (essentially power usage) and lumens (light output). For example, an incandescent might operate at about 12-15 lumens-per-watt (lm/W), while an LED bulb will be in the range of 40-50, a much greater luminous efficacy (Table1-1). CFLs stack up well when it comes to lumens-per-watt, but they dont have the lifespan of LEDs. CFLs have all sorts of other issues that well address later, such as problems with disposal. And those LED bulbs? They are just todays basic, commercially available LEDscutting edge models can be much more efficient. These models might produce over 150 lm/W, and even higher than that in laboratory settings.

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2. Key Terms

Sal Cangeloso Maker Media, Inc ePub

You cant get very far talking about LED lighting without understanding the lingo. Of course, terms like lumens and kilowatt-hour are important, but a new technology always introduces new concepts to understand.

CRI is technically, according to the American National Standards Institute, the measure of how similar colors appear under illumination by a test source, compared to under a reference source that has the same correlated color temperature.

In practice, its often known as the color accuracy, a numerical rating of the color quality produced by a light source. Incandescent bulbs are the benchmark for the test (scoring 100) while a good LED bulb will be rated at 80 or above (this number will almost always be printed on the back of the box). Incandescentsand the sun, for that matterare the baseline because they emit light at all points along the visible spectrum, while LEDs and CFLs have a spiked, intermittent pattern. Higher CRI value bulbs are available for graphic designers, art galleries, artists, and so forth. But they increase the cost and most consumers wont notice a considerable difference above 80. When using a bulb with a score below 80, the results will vary based on the qualities of the particular bulb, but viewers will typically observe the color of the surrounding objects to be dingy. Red and blue tones will appear to be off and skin tones can look unhealthy.

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3. LED Basics

Sal Cangeloso Maker Media, Inc ePub

LEDs come in a number of shapes and forms (including the organic LED and polymer LED), but the basic LED is a semiconductor. They are small, long-lasting, and power efficient. They are made of a semiconductor material in order to produce the desired color tones.

How LED works is not particularly complex from a scientific point of view, but its quite far removed from the purchase and usage of LED lighting. Lots of information is available if youd like to dig deeper into the physics and chemistry behind semiconductors, but it should suffice to say that an LED is a diodea device that allows electricity to pass through it in a single directionthat emits light. That light can range from infrared (non-visible) through the color spectrum, depending on the semiconductor material that is used. For example, a red LED might use aluminium gallium indium phosphide (AlInGaP) and a particular voltage drop (from one side of the diode to the other) to emit the desired color.

White light is the combination of all of the colors in the visible spectrum. Because of this it can result in a number of shades, and producing it is not as easy as just using a particular semiconductor material. There are a number of different methods for producing white light, some of which are more energy efficient than others, and some methods are patented by particular companies. Once you factor in this information and secondary facts, such as the blue LED light is cheaper to produce than white light, then you can start to understand why LED lighting is such a scientific enterprise.

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4. The Bulb

Sal Cangeloso Maker Media, Inc ePub

There isnt a whole lot to the typical LED bulb. In addition to the standard gearthe base, lens (optics), and/or reflectorthere is a driver, which is explained in more detail below; PCB, LEDs, an encapsulant over the LEDs, a phosphor, and usually some sort of a heat sink. The ideal scenario (or the goal for some manufacturers, at least) is for the LEDs, hardware (cooling materials, etc.), and driver to each make up for one third of the cost of the bulb, but thats essentially just a rule of thumbreal-world demands and technology issues often get in the way of such ideals. As with any other manufactured product, its all about tradeoffs. By investing more in the cooling, its possible to run more power through the LEDs, which means you can use fewer of them to get the same amount of light. Similar tradeoffs must be made, for example, between the quality of the light and the efficiency of the bulb.

The driver is essentially the lamps power supply, but because this is a modern light source, there is some intelligence built in as well. The driver, which usually lives at the base of the bulb, is able to not just transform the energy the bulb takes in to what the LEDs need, but also to do things like throttle the power being sent to the LEDs if it senses that the unit is too hot. This will not only prevent possible damage to the surrounding area but it will extend the life of the LEDs.

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Gordon Meyer (7)
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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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2. Office

Gordon Meyer O'Reilly Media ePub
Medium 9780596007225

3. Kitchen and Bath

Gordon Meyer O'Reilly Media ePub
Medium 9780596007225

4. Bedroom

Gordon Meyer O'Reilly Media ePub
Medium 9780596007225

5. Garage and Yard

Gordon Meyer O'Reilly Media ePub

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