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Archive for the ‘Techno Stop’ Category

What Is Bluetooth Dongle?

Posted by Ramesh Khati on July 19, 2009

Bluetooth Dongle

Bluetooth Dongle

Bluetooth dongle is simply defined as an accessory to the computer. By using a Bluetooth dongle a computer can be wirelessly linked to other devices. By using these dongles one can easily connect a computer with any other computer, printer, digital cameras or cellular devices. Actually Bluetooth dongle possesses a small microchip, which makes it capable of connecting and exchanging the data with all other devices which contain such microchips and with all other dongle devices. USB ports are used to connect a Bluetooth dongle with the computer. Just like other USB attachments these dongles also get powered from computers itself. Once we disconnect a Bluetooth dongle it gets deactivated on its own.

Uses of the dongle

Bluetooth dongle allows data transmissions at the rate of 1 Mbps. Type of the transmitted data depends upon the type of the profile of the Bluetooth dongle. As an example we can consider the case of “Bluetooth headsets”, they can be used for receiving and transmitting sound data only. At a time, Bluetooth connection can be made between more than two devices. When more then 2 Bluetooth devices are in activated state within a particular zone, then shared network of these devices will be called as PAN or personal area network. Range of this PAN depends upon the class of the microchips of the connected devices. Range varies between 1-100 meters.
In earlier days, there was not any specified protocol or guideline decided for Bluetooth connectivity. So, presence of various connectivity technologies made it extremely hard to synchronize the devices wirelessly. To deal with this problem, a standard protocol was published by a consortium of various companies concerned with computing, telecommunication and electronics. To bring a boom in Bluetooth market, members of this consortium decided to design Bluetooth chips as a compact and simple device. These new Bluetooth chips were easy to use; they were economic and less power consuming. These easy chips lead into production of small and easy Bluetooth dongles with easy prices.

Bluetooth dongles are extremely easy to use; in fact, they are based on the concept of plug and play. They are compatible with operating systems like Windows, vista, Linux and Macintosh etc. No software is needed to install in order to activate a Bluetooth dongle. To activate a Bluetooth dongle all it need is, plugging into the USB port of the computer.

Applications of the Bluetooth device

1. Wireless communication between hands-free headset and a mobile phone.

2. Wireless networking of the computers at a confined space.

3. File and transfer

4. PS 2 and Nintendo’s Wii, gaming systems use Bluetooth for wireless controllers.

5. Bluetooth dongles can be used to access dial-up internet on computers.

6. Advertisement concepts and flash objects can be easily sent from one device to another confidentially.
7. Replacement of infrared in traditional controlling units.

8. Calendar notes, contact details, list of appointments, reminders etc can be easily shared between devices.

9. Fantastic medium of communication between PC output and input devices.

So we can conclude that Bluetooth dongle is an unmatched electronic discovery which is simplifying the field of data transmission and internet access.


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How Microwave Cooking Works

Posted by Ramesh Khati on May 12, 2009

How Microwave Cooking Works

Inside Microwave Oven

Inside Microwave Oven

A Microwave Oven

A Microwave Oven

You often hear that microwave ovens cook  food “From the inside out.” What does that mean? Here’s an explanation to help make sense of microwave cooking.

Let’s say you want to bake a cake in a conventional oven. Normally you would bake a cake at 350 degrees F or so, but let’s say you accidentally set the oven at 600 degrees instead of 350. What is going to happen is that the outside of the cake will burn before the inside even gets warm. In a conventional oven, the heat has to migrate by conduction from the outside of the food toward the middle. You also have dry, hot air on the outside of the food evaporating moisture. So the outside can be crispy and brown (for example, bread forms a crust) while the inside is moist.
In microwave cooking, the radio waves penetrate the food and excite water and fat molecules pretty much evenly throughout the food. No heat has to migrate toward the interior by conduction. There is heat everywhere all at once because the molecules are all excited together. There are limits, of course. Radio waves penetrate unevenly in thick pieces of food (they don’t make it all the way to the middle), and there are also “hot spots” caused by wave interference, but you get the idea. The whole heating process is different because you are “exciting atoms” rather than “conducting heat.”

In a microwave oven, the air in the oven is at room temperture, so there is no way to form a crust. That is why microwavable pastries sometimes come with a little sleeve made out of foil and cardboard. You put the food in the sleeve and then microwave it. The sleeve reacts to microwave energy by becoming very hot. This exterior heat lets the crust become crispy as it would in a conventional oven.

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What is 3G?

Posted by Ramesh Khati on May 9, 2009

What is 3G?

A radio communications technology that will create a “bit pipe” for providing mobile access to internet-based services. It will enhance and extend mobility in many areas of our lives.

In the near future, mobility won’t be an add-on: it will become a fundamental aspect of many services. We’ll expect high-speed access to the internet, entertainment, information and electronic commerce (e-commerce) services wherever we are – not just at our desktop computers, home PCs or television sets.

3G services will add an invaluable mobile dimension to services that are already becoming an integral part of modern business life: Internet and Intranet access, video-conferencing, and interactive application sharing.

2G Wireless

The technology of most current digital mobile phones

Features includes:
– Phone calls
– Voice mail
– Receive simple email messages

Speed: 10kb/sec

Time to download a 3min MP3 song:
31-41 min

2.5G Wireless

The best technology now widely available

Features includes:
– Phone calls/fax
– Voice mail
-Send/receive large email messages
– Web browsings
– Navigation/maps
– New updates

Speed: 64-144kb/sec

Time to download a 3min MP3 song:

3G Wireless

Combines a mobile phone, laptop PC and TV

Features includes:
– Phone calls/fax
– Global roaming
– Send/receive large email messages
– High-speed Web
– TV streaming
– Electronic agenda meeting reminder.

Speed: 144kb/sec-2mb/sec

Time to download a 3min MP3 song:

We are not just talking about “road warriors” who spend their entire lives travelling. It’s more a question of supporting new, flexible working practices where employees need access to a wide range of information and services via their corporate intranets, whether they are at their own desk or anywhere else.

Employees who spend some of their working at home. Accountants that carry out audits at client premises. On-site maintenance engineers who need access to detailed instruction manuals, mobile emergency services who need a video link with a hospital or doctor for specialised advice. These are a few situations where 3G will play a valuable role.Key features of 3G systems are a high degree of commonality of design worldwide, compatibility of services, use of small pocket terminals with worldwide roaming capability, Internet and other multimedia applications, and a wide range of services and terminals.

3G System Capabilities

Capability to support circuit and packet data at high bit rates:

• 144 kilobits/second or higher in high mobility (vehicular) traffic
• 384 kilobits/second for pedestrian traffic
• 2 Megabits/second or higher for indoor traffic
Interoperability and roaming

Common billing/user profiles:

• Sharing of usage/rate information between service providers
• Standardized call detail recording
• Standardized user profiles
Capability to determine geographic position of mobiles and report it to both the network and the mobile terminal

Support of multimedia services/capabilities:

• Fixed and variable rate bit traffic Bandwidth on demand
• Asymmetric data rates in the forward and reverse links
• Multimedia mail store and forward
• Broadband access up to 2 Megabits/second

We’re likely to see 3G services enter our day -to-day lives in all sorts of new ways: for example, in shopping, especially Internet “mail order” (e-commerce), banking, or playing interactive computer games over the Net.

We’ll think nothing of sitting on a train and using a mobile palmtop with Internet browser to log into our bank accounts. While on-line we’ll be able to check our accounts, pay a few bills and click on a screen icon to immediately set up a video-conference to discuss our account with a bank clerk.

On vacation, we’ll be able to use our mobile palmtops to obtain local tour guides, make a last-minute reservation at a hotel, find and call the nearest taxi firm, and send video postcards. We’ll expect location-independent mobile access to a personalised set of services that matches the way we live and work.

Increasingly, machine-to-machine communications will also be enabled and enhanced with future mobile network technology. Domestic appliances will have built-in radio modems to provide remote control and diagnostics. Our refrigerators will have built-in sensors that detect which items need restocking and automatically send a reminder message to our Personal Digital Assistants (PDAs). We could even get the refrigerator to send an order direct to our local store. Likewise, vending machines will be able to tell the warehouse when they need restocking.

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What is Wi-Fi?

Posted by Ramesh Khati on May 8, 2009


Wi-Fi, which stands for wireless fidelity, in a play on the older term Hi-Fi, is a wireless networking technology used across the globe. Wi-Fi refers to any system that uses the 802.11 standard, which was developed by the Institute of Electrical and Electronics Engineers (IEEE) and released in 1997. The term Wi-Fi, which is alternatively spelled WiFi, Wi-fi, Wifi, or wifi, was pushed by the Wi-Fi Alliance, a trade group that pioneered commercialization of the technology.

In a Wi-Fi network, computers with wifi network cards connect wirelessly to a wireless router. The router is connected to the Internet by means of a modem, typically a cable or DSL modem. Any user within 200 feet or so (about 61 meters) of the access point can then connect to the Internet, though for good transfer rates, distances of 100 feet (30.5 meters) or less are more common. Retailers also sell wireless signal boosters that extend the range of a wireless network.

Wifi networks can either be “open”, such that anyone can use them, or “closed”, in which case a password is needed. An area blanketed in wireless access is often called a wireless hotspot. There are efforts underway to turn entire cities, such as San Francisco, Portland, and Philadelphia, into big wireless hotspots. Many of these plans will offer free, ad-supported service or ad-free service for a small fee. San Francisco recently chose Google to supply it with a wireless network.

Wifi technology uses radio for communication, typically operating at a frequency of 2.4GHz. Electronics that are “WiFi Certified” are guaranteed to interoperate with each other regardless of brand. Wifi is technology designed to cater to the lightweight computing systems of the future, which are mobile and designed to consume minimal power. PDAs, laptops, and various accessories are designed to be wifi-compatible. There are even phones under development that would switch seamlessly from cellular networks to wifi networks without dropping a call.

New wifi technologies will extend range from 300 feet (91.5 meters) to 600 feet (183 meters) and beyond, while boosting data transfer rates. Most new laptops nowadays come equipped with internal wireless networking cards.

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How does Photo Copiers work?

Posted by Ramesh Khati on April 16, 2009

Photocopier MachinePhotocopier Machine

working principle of photocopier

working principle of photocopier

The photocopier (commonly called Xerox® Machine) was a machine designed by an engineer working as a patent attorney. The principle is to spray electric charge upon the smooth surface of a semiconductor, and then flash an image of the material to be copied onto this plate. The light causes the plate to discharge in that local area, and when pigment powder is sprinkled over the plate, it sticks to the charged spots and falls off the discharged spots. The plate is then placed in contact with a blank sheet of paper to which the powder is transferred, then the paper is heated to stick the pigment to the paper. the fuser melts the toner into the paper permanently. This is why some Xerox copies, particularly those made at the end of a long printing run, can feel very warm to the touch.

After each run of copies has been completed, a Corona wire essentially clears off the photoreceptor drum or belt by running a new positive charge. Because many photoreceptor drums are smaller in diameter than the length of the copy paper, it is not unusual for the photocopying process to be duplicated several times over as the original document is scanned. The drum may have to be recharged positively to eliminated the older information and receive the new images several lines at a time. All of these actions are carefully synchronized in order to produce a photocopy in the time it takes for the lamp to scan across the original one time.

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