What is the best HDTV for you? Plasma, LED or LCD HDTV?

Making the right choice between LCD, LED or plasma HDTV is not a simple task. There are a variety of models, brands and technologies. With so many options, never been so difficult to choose an HDTV.

Some years ago, the only difference between the models were on the mark. The situation began to change with the arrival of terms such as HDTV, response time, Full HD, among others. Currently, each category of HDTV has its own characteristics. The Plasma TV was the first technology that enabled the production of thin TVs with larger screens and higher image quality. The LCD TV arrived soon after, and many said it was the end of the Plasma – which did not happen, because sales of Plasma TV still growing every year. The LCD technology has dominated the computer market and arrived in the HDTV market with the strength to play space. First there was the 27-inch LCDs and 32-inch. Then came larger and with better image quality.

The news then was the LED TVs. In general, the big difference between LCD vs. LCD with LED is lighting. In LCD with LED in place of fluorescent lamps to illuminate the screen, enter small filets of LEDs on the sides (or rear) to generate the lighting.

So which model to buy? Where to begin the decision of choice? A Plasma HDTV? An LCD HDTV? Or the new LED LCD? It is not yet possible to say which technology will stand out. The truth is that you should try to find among the many options that technology that most meets your desires and intentions.

What are Telescopes and its Benefit?

A telescope "telescope" is an instrument designed for the observation of remote objects. The term usually refers to optical telescopes, but there are telescopes for most of the spectrum of electromagnetic radiation and for other signal types. An optical telescope is an optical tool that gathers and focuses electromagnetic radiation. Telescopes increase the apparent angular size of distant objects, as well as their apparent brightness. Telescopes work by employing one or more curved optical elements - lenses or mirrors - to gather light or other electromagnetic radiation and bring that light or radiation to a focus, where the image can be observed, photographed or studied. Optical telescopes are used for astronomy and in many non-astronomical instruments. The main purpose of a telescope is to gather light, i.e. to collect and focus photons.


We can think of a telescope then as a "light bucket" - the bigger the bucket, the more photons a telescope can collect. Types of telescopes: There are three basic types of telescopes -- Refractors, Newtonian reflectors, and Catadioptrics.

Newtonian Reflector Telescopes: Newtonians usually use a concave parabolic primary mirror to collect and focus incoming light onto a flat secondary mirror that in turn reflects the image out of an opening at the side of the main tube and into the eyepiece.

Refractor Telescopes: Refracting telescopes have an objective lens at the front of the tube. The light exits out through the back of the tube to the eyepiece. Since many observations are made high in the sky, a right-angle diagonal is used to avoid neck strain. This also provides an upright image making them suitable for terrestrial observations. A refractor has several advantages over other designs. The tubes are enclosed so that dust and moisture do not enter the tube, they have fixed optics that do not normally require collimation, and they do not have a central obstruction which reduces the light entering the tube. A refractor typically will give higher quality images of planets than other telescopes of similar aperture.

Catadioptric Telescopes: Telescopes using a combination of both mirrors and lenses are called catadioptrics. There are many different designs. Examples of these are the Schmidt-Cass grain and the Maksutov-Cassegrain. Usually a full aperture lens is used to correct aberrations in a compound reflecting telescope. The corrector lens also increases the performance of the instrument as air currents are eliminated. The main advantage of the design is that, because the light path is folded back on itself, it provides a very portable, short physical length telescope with a long focal length.

Benefit: -
1. The aperture of a telescope is several times larger than the aperture of human eye so that the objects that can not be normally seen by unaided eye can be seen. Light- gathering power of a telescope is proportional to the area of its aperture and hence depends on the square of the radius of the mirror. Therefore a 20 cm diameter telescope collects four times more photons than a 10 cm diameter telescope.

2. A telescope can be equipped to record light over a long period of time, by using photographic film or electronic detectors such as photometers or CCD detectors while the eye has no capability to store light. A long-exposure photograph taken through a telescope reveals objects too faint to be seen with the eye, even by looking through the same telescope.

3. A third major advantage of large telescopes is that they have superior resolution, the ability to discern fine detail. Small resolution is good. The resolution is directly proportional to the wavelength being observed and inversely proportional to the diameter of the telescope.

Things You Need to Know Before You Buy Digital Camera

Digital cameras come in many sizes, colors, brands, zooms, resolutions, playbacks, etc. There are so many features and qualities that are being placed in the devices that buyers especially first timers become overwhelmed and dizzy with these outstanding arrays of gadgets. This is even without including the various advertisements and different ratings that are used to promote these products. So what are the things to look for if you want to buy digital camera?


To be able to answer these, there are 2 sets of information you have to know before you can decide. The first type of information is defining what YOU need and want in a digital camera. To do this, you can ask yourself the following questions: What do you want to take with your digital camera? Before you buy digital camera, it is important to determine what kind of pictures you want to take with it. If you are a digital photography enthusiast, any digital camera will not just do. You have to look for features that can support the zooming you need, the resolution, etc. 


How much is your budget? This is a very important question any person who intends to buy digital camera should ask. Because no matter what your needs and wants are for the device, your financial resource will play a huge part in dictating the type of digital camera you will buy. What are you resources? When you buy digital camera, sometimes the spending does not end there. You also have to consider the capacity and the power of the computer and the printer you will be hooking your camera with for your editing and printing needs. Editing software are already included when you buy digital camera but other devices aren't. Aside from a printer, ink and paper for printing, you might also need additional memory cards for your camera and a more powerful computer to support image editing and image storage and retrieval.

After answering these 3 questions, the second set of information you need to know before you buy digital camera are the features that you need in the device. These are:

Resolution. Before you buy digital camera, check first its capacity to produce high quality photo images. The number of pixels indicated determines resolution. The more number of pixels, the higher the resolution which can make photos to be enlarged without losing image quality. Built-in memory. Digital cameras need memory cards for picture storage. When you buy digital camera, make sure that the gadget that you buy does not only have a "built-in" memory but should also have a card slot for external and additional memory. This allows you to change full memory cards conveniently while shooting your pictures. Look and feel. It is essential for you to feel comfortable holding your digital camera while shooting.


So, before you buy digital camera, it good to test and check if you are comfortable holding it and using it. Consider where the buttons are located and how they are spaced out and see also if you feel comfortable using the viewfinder. Battery life. Digital cameras use up batteries fast and batteries are expensive. Before you buy digital camera, consider if the camera's batteries are rechargeable. This way you can recharge them. Take also into consideration an AC adapter when you buy digital camera. You can attach this to the camera when you are viewing your pictures or uploading them. LCD. The LCD is a special consideration you have to look into when you buy a digital camera. This is a small screen located at the back of a digital camera that allows you to preview the pictures you took. This has to be considered when you buy digital camera because it uses up a lot of battery power.


Special features:-
Special features that will suit your needs should be thought about, too before you buy digital camera. If you want your camera to have good zooming, you can opt for those with optical zoom lenses. A diopter adjustment on the digital camera's viewfinder will also be beneficial to those who regularly wear glasses and wish to buy digital camera. Other features such as remote control, tripods, etc. can also be considered when you buy a digital camera. With these information, you can now figure out what you really need and want before you buy digital camera. If you want to see ratings and rankings of these devices based on price, resolution or other features, check out various websites that have these in the Internet.

Digital cameras come in many sizes, colors, brands, zooms, resolutions, playbacks, etc. There are so many features and qualities that are being placed in the devices that buyers especially first timers become overwhelmed and dizzy with these outstanding arrays of gadgets. This is even without including the various advertisements and different ratings that are used to promote these products.

Difference Between Analog and Digital?

Analog and Digital As a technology, analog is the process of taking an audio or video signal (the human voice) and translating it into electronic pulses. Digital on the other hand is breaking the signal into a binary format where the audio or video data is represented by a series of "1"s and "0"s. Simple enough when it's the device—analog or digital phone, fax, modem, or likewise—that does all the converting for you.

Digital versus analog can refer to method of input, data storage and transfer, the internal working of an instrument, and the kind of display. The word comes from the same source as the word digit and digitus. The digital technology breaks your voice (or television) signal into binary code a series of 1s and 0s transfers it to the other end where another device (phone, modem or TV) takes all the numbers and reassembles them into the original signal. The beauty of digital is that it knows what it should be when it reaches the end of the transmission.


That way, it can correct any errors that may have occurred in the data transfer. What does all that mean to you? Clarity. In most cases, you'll get distortion-free conversations and clearer TV pictures. The nature of digital technology allows it to cram lots of those 1s and 0s together into the same space an analog signal uses. Like your button-rich phone at work or your 200-plus digital cable service, that means more features can be crammed into the digital signal. Digital offers better clarity, but analog gives you richer quality. Digital like the VCR or the CD is coming down in cost and coming out in everything from cell phones to satellite dishes.


Phone lines
•Digital lines are found in large, corporate phone systems. Though digital lines carry lower voltages than analog lines, they still pose a threat to your analog equipment.

•Analog lines also referred to as POTS (Plain Old Telephone Service), support standard phones, fax machines, and modems. These are the lines typically found in your home or small office.


•There are digital-to-analog adapters that not only let you use analog equipment in a digital environment, but also safeguard against frying the internal circuitry of your phone, fax, modem, or laptop.


Cordless phone

•The very nature of digital technology—breaking a signal into binary code and recreating it on the receiving end—gives you clear, distortion-free cordless calls.

•Cordless phones with digital technology are also able to encrypt all those 1s and 0s during transmission so your conversation is safe from eavesdroppers. Plus, more power can be applied to digital signals and thus, you'll enjoy longer range on your cordless phone conversations.

•The advantage to analog cordless products? Well, they're a bit cheaper. And the sound quality is richer. So unless you need digital security, why not save a few bucks and go with an analog phone? After all, in home or small office environments where you may be the only cordless user, you won't have any interference issues.

•Keep in mind, when talking about digital and analog cordless phones, you're talking about the signals being transferred between the handset and its base. The phones themselves are still analog devices that can only be used on analog lines. Also, the range of your cordless phone—analog or digital—will always depend on the environment.


Cellular Phones

•Perhaps the most effective use of the digital versus analog technology is in the booming cellular market. With new phone activations increasing exponentially, the limits of analog are quickly being realized.

•Digital cellular lets significantly more people use their phones within a single coverage area. More data can be sent and received simultaneously by each phone user. Plus, transmissions are more resistant to static and signal fading. And with the all-in-one phones out now—phone, pager, voice mail, internet access—digital phones offer more features than their analog predecessors.

•Analog's sound quality is still superior—as some users with dual-transmission phones will manually switch to analog for better sound when they're not concerned with a crowded coverage area—but digital is quickly becoming the norm in the cellular market.


Better Sound Quality
Digital offers a better quality of sound. Proponents of digital claimed too that because digital scrambled up the signals into bursts, it was more secure than analog and can help thwart "cloning," an act of grabbing phone account information over the air in order to copy then resell that information for piracy purposes. By some industry estimates, close to $650 million in wireless services has been coveted by these big-eared crooks, which only adds onto the operator's bottom line a cost that is eventually passed on to the customer. Digital has stronger battery life than analog, and for the most part, better, more modern features on the phones.

The Future of Identification Technology

The future of identification technology is long and rich, just as its history. From the days of not even being able to read finger prints, we've come to retinal scans, fingerprint identification and even body scans. And as identification technology continues to evolve, it will become increasingly more sophisticated.

Today we traditionally use a laminated ID card alone or in conjunction with biometric technologies of all types, depending on the situation and industry. The increased use of ID cards with biometric technologies is in direct response to higher security concerns and an atmosphere that greatly values identity.

A huge part of the identification technology of the future is RFID, or radio frequency identification technology. Using RFID technology, a number of things are possible, including full body scans—at home. For example, say you and your family are going away for the weekend and you've engaged your neighbor to care for your animals, but want to ensure only your neighbor can enter.

Instead of a key, all you'd need to do is program their body information into your scanner and set it exclusively to them. Upon scanning, your door would open. While this sounds like science fiction, it is a very real possibility that, according to popular science, will be available in the 2020's.

Or how about the already available laptops that offer biometric security technology? All you do is place your thumb on the reader and your laptop is unlocked or locked, allowing for maximum security even if it's lost or left somewhere.

Additionally, experts are predicting that within the next ten years, the US will see a national identification card system. It's conceivable that such an ID card would use various technologies together, such as RFID, thumbprint identification, and a rewritable microchip that contains your history, medical background, insurance information and other statistics combined into one license or national ID card that would outdate even a license.

Thus, the future of ID technology is rapidly expanding and growing at a startling rate. Within the next ten to twenty years, advances in biometric and RFID technology may grow to the point that even regular homes will have technologies like body scanning and much, much more.

Alphacard.com is designed to help you learn everything about plastic ID cards, ID badges and ID card systems. Browse identification industry news, learn about the ID card printers of major manufacturers like Fargo, Zebra-Eltron, Magicard and Evolis, or buy any and all ID card systems and accessories. Our company has been dedicated to giving you the best service and the best value anywhere since 1986.

Designing with microcontrollers

When comes time to design a circuit with a microcontroller, there are many aspects to consider.

How many I/O pins are required, is there enough digital to analog output, is there enough memory for the program… All these aspect are solved in a minute just by choosing at the catalog of any microcontroller manufacturer.

But the most critical aspect of any electronics project are the time and the money.

Let’s say you work on a minimally professional project for your own or for a customer.

The time affected elements are the software design and the printed circuit board (pcb) design. One week to develop your software, one more week to draw your pcb, one more week to wait for the pcb manufacturing, while you create the bill of material, find components suppliers and place the components order.

If you are lucky, you receive your bare pcb at the end of the 3rd week.

Money affected elements: you possibly ordered 10 units of this bare pcb for approximately 500$, and you possibly ordered enough components to assemble these 10 circuits for 200$. You are now working on this project since 3 weeks, may be 4 weeks considering inevitable delays, so add 4 weeks of salary to the project. Let’s say 2400$. Since you are using surface mount (SMT) components in your design, don’t forget to add a stereo-microscope, $1000, a regulated soldering iron with wave tip, 150$, plus miniature tools, tweezer, flux, flux remover,…, 50$.

There you start assembling your first circuit as a prototype, hoping not too many mistakes on the pcb to minimize the patches. You achieve soldering the pcb and start flashing the microcontroller and attempt debugging the software. At the end of the week everything seems stable and you may complete some other pcb for your customer and keep 5 pcb as spare.

You have now reach 5 weeks of work for 3000$ in salary and close to 1900$ in related fees, assuming you are quite professional in all the aspect of electronics design and software development and not adventuring yourself for the first time with SMT components.

Obviously, I did not consider your personal computer, neither the pcb design software that you might possibly own. If not, add it to the total, 1500$, for a total of 6400$.

One other way to attack this design situation would have been to consider pre-assembled electronics modules.

Since many years you may find on the market different microcontroller peripherals like opto-isolated relay board, servo control board, motor control board, and sensors of all kind.

You may also find market pre-assembled unit of SMT microcontrollers, from 20$ to $100, depending on number of I/O pins.

The major problem I encountered with these is that they are all mounted on DIP pins forcing me to use or design a carrier pcb to connect to them. Not really time saving solution. They are more suitable for prototyping on breadboard.

One interesting discovery I made is the circuit MT0401 from Marcius Technologies Inc.

It’s like a miniature pre-assembled microcontroller built around the smallest package of the PIC18F452 from Microchip, having its own carrier board. The circuit includes one LED on each I/O pins, acting as a 32 real time logic probes. The circuit is also easily attachable with professional Snaptrack. It’s having removable and reusable section. It’s an open design, allowing user to choose his own header for connections. It’s also very easy to supply.

The logic probes are helpful while debugging and the same circuit is directly integrated in the delivered project as a brain circuit. No other pcb required, you flash it, you connect it to your peripherals and that’s it. Not bad for 89$.

Considering all the time and money saving aspect of this product, you may achieve your project in one week. I’ll let you evaluate the total saving.