The $2.5 Billion rover of NASA, Curiosity is all set to take the tiniest detail of the planet Mars. The rover is designed to be highly precise in observing its ambient conditions including atmospheric pressure and the gravitational force. For this purpose, it’s Instrumental Control Unit or the ICU has been equipped with pressure sensors. These sensors will help in detecting the Dust Devils that are a characteristic of the planet and will also detail with the concentration of various gases in the atmosphere at various points. Let’s have a look on what makes a pressure sensor capable enough to perform such specific tasks and where else it can be used.A pressure sensor is a device which senses pressure and converts it into an analog electric signal whose magnitude depends upon the pressure applied. Since they convert pressure into an electrical signal, they are also termed as pressure transducers.
SPEED – a buzz word in today’s scenario, is a measure of “how fast”. Everybody is in a rat race and wants to run at the fastest speed. ‘Speed’ is used in variety of contexts and is measured using variety of methods in their own contexts.According to physics, speed is related to motion. Distance travelled by a moving body in a given time is called speed. Other related terms are angular speed, velocity, and angular velocity. Angular speed is the angular distance per unit time. (Linear) Velocity and angular velocity are vector quantities and are defined as displacement (linear/angular) per unit time.Speed is measured using different kinds of sensors operating on different principles. Subsequent sections will discuss various kinds of sensors used for measurement of speed (and related vector quantity, velocity).
Instruction Set Architecture(ISA) is important from user’s/ compilers perspective. Instruction Set Architecture is a ‘functional appearance to its immediate user/programmer’. ISA involves details like addressing modes, opcodes, registers, etc. Microarchitecture is important from the perspective of processor designer. Microarchitecture defines the logical structure or organisation that implements ISA. It involves details of pipelining stages, caches, physical registers, functional units, etc.Realization of hardware is important from the perspective of chip designer. Hardware is the actual “physical structure that embodies the implementation.” It involves micro-details of gates, transistors, wires, etc.Processors having identical ISA may be very different in organization. Processors with identical ISA and nearly identical organization are still not nearly identical.
Networking is playing vital role in current IT era where data distribution and access is critically As the use of communication between important. two or more entities increases the networking technologies need to be improved and refurbished over time. Similarly the transmission media, the heart of a network, has been changed with the time improving on the previous one. If you know a little bit about networking you surely have heard the term Ethernet which is currently the dominant network technology.Wide spread of the Ethernet technology made most of the offices, universities and buildings use the technology for establishment of local area networks (LANs).To understand what actually Ethernet is, we need to know about IEEE first which is a short of Institute of Electrical and Electronics Engineers. IEEE is a part of International Organization for Standardization (ISO) whose standard IEEE 802.3 is defined for Local Area Network.
All of us probably are aware about the fact that the magnets create magnetic fields; earth has a magnetic field; current flowing in a wire also generate magnetic field. But have we ever realized that the fields are generated also by our heart and brain. However, what differs between the magnetic field generated by a magnet and that generated by brain and heart is the magnitude of magnetic field. Following figure shows the magnitude of magnetic fields generated by various sources. We all are surrounded by magnetic fields. Magnetic fields are generated by flowing electrical current in various electrical/electronic appliances; TV, computers, power transmission lines, etc. Earth also has its own magnetic field, though relatively small. Earth magnetic field is largest at the poles (~ 60 000 nT) and smallest as the equator (~ 30 000 nT). The earth’s magnetic field strength is proportional to 1/r3 (until the influence from the solar wind gets noticeable).
Measuring a voltage in any system is a “passive” activity as it can be done easily at any point in the system without affecting the system performance. However, current measurement is “intrusive” as it demands insertion of some type of sensor which introduces a risk of affecting system performance. Current measurement is of vital importance in many power and instrumentation systems. Traditionally, current sensing was primarily for circuit protection and control. However, with the advancement in technology, current sensing has emerged as a method to monitor and enhance performance. Knowing the amount of current being delivered to the load can be useful for wide variety of applications. Current sensing is used in wide range of electronic systems, viz., Battery life indicators and chargers, 4-20 mA systems, over-current protection and supervising circuits, current and voltage regulators, DC/DC converters, ground fault detectors, programmable current sources, linear and switch-mode power supplies, communications devices , automotive power electronics, motor speed controls and overload protection, etc.
Humidity is the presence of water in air. The amount of water vapor in air can affect human comfort as well as many manufacturing processes in industries. The presence of water vapor also influences various physical, chemical, and biological processes. Humidity measurement in industries is critical because it may affect the business cost of the product and the health and safety of the personnel. Hence, humidity sensing is very important, especially in the control systems for industrial processes and human comfort. Controlling or monitoring humidity is of paramount importance in many industrial & domestic applications. In semiconductor industry, humidity or moisture levels needs to be properly controlled & monitored during wafer processing. In medical applications, humidity control is required for respiratory equipments, sterilizers, incubators, pharmaceutical processing, and biological products. Humidity control is also necessary in chemical gas purification, dryers, ovens, film desiccation, paper and textile production, and food processing.
Day-in and day-out we have been using electronic scales or weighing machines. You go to any grocery store or a jewellery shop; the items are weighed using electronic weighing machines (Weighing balances are also used in situations where very high accuracy is not of paramount importance). But, have we ever given a thought on the mechanism of the electronic scales? At the heart of electronic scales or weighing machines is a sensor called load cell. These sensors sense the force (or weight) of the items and the electronic circuitry processes the sensors’ output and displays it on the indicator. Load cells are highly accurate transducers which provide the user with information not generally obtainable by other technology due to commercial factors. Usage of load cell is not limited to electronics scales; they are used load testing machines, industrial scales, flow-meters, etc., though we hardly ever come in direct contact with the load cells.
“A small step for man, but a giant leap for mankind”, such were the words that travelled through space all the way from the Moon to our television sets as frames of Armstrong’s setting foot on the moon flashed across 600 million screens. It was indeed a technological milestone. But have ever wondered that people were sitting in their living rooms watching a mortal reach an alien land and show to you live pictures from there. Much before that feat, the technology to transmit video had been developed and was in itself a technological achievement. About half a century later, two-way communication involving real-time streaming of video and audio is becoming commonplace with almost every smart phone. Videoconferencing is a technology by means of which two or more parties situated in different geographical locations can watch and converse with each other by means of two-way transmission of video and audio data in near real-time. From once being a high profile, owned by a famous few, this technology has made inroads to every middle class homestead that owns a healthy broadband connection.
“Have you seen the remote?” “I left it on the table after watching my matinee show”. “It is not here, I will miss the news again because of you!!!” In the near future, such heated discussions over remote control won’t disturb the harmony of the house. Not because they will place it correctly but because soon remote controls will be the objects of the past. Technology has finally reached that dimension when our hands will take over the job and replace them by directly communicating with the computer or television. For instance, in order to delete a folder or file from the computer, place your palm on it, and throw it like a paper in a dustbin. Even while using the microwave oven to bake a cake, waving our hands in the air like a magician would serve as a command for the oven. While some of us might be thinking of it being a futuristic vision, some of us have already experienced it through what we call “Gesture Recognition Technology.”
Primary requirements for any wireless mode of communication include high quality of service and data secrecy. Realizing that these two factors are to be fulfilled in the most optimized ways without the costs going too high, CDMA, a spread spectrum based technology came into existence. Initially restricted to the armed forces, this technology was commercially launched in 1995 by Qualcomm Telecommunications and now, as per Q4 of the year 2011, CDMA has over 8 billion voice and data customers in the 122 countries that it operates. CDMA is regarded as an improvement over GSM technology whose need can be easily understood by taking a simple example. Consider 5 couples that have their respective partners in different rooms. The partners are permitted to communicate only to each other and each is provided with a communication instrument for the purpose.
‘The world is getting warmer day by day.’ This sentence has started to crop up every now and then in our day to day lives. But seldom do we wonder what it means. What is warmer? How warm is warm? Is it hotter than hot, or just hotter than cold? To our human senses, temperature is only a subjective evaluation. For an objective and reproducible measurement, we need to quantify the temperature values, and to do that, a suitable measurement device is required. This is achieved through the use of temperature sensors. Simply speaking, temperature is the degree of hotness of the body or, a measure of the heat content in the body. The problem to quantify the heat content of the body on a scale did not arise until the invention of the Steam Engine. The curiosity of scientists to understand the behavior of water at different levels of hotness gave rise to a better laid out study.
People have grown up with the sights and sounds of fluorescent lamps buzzing to life after a few attempts. As the new wave of energy saving appliances gripped the world, technology made the fluorescent lamps shrink in thickness as well as reduced the number of attempts made by lamps to shine their brightest. Today many homes use energy Saver CFL lamps and fluorescent tubes which start giving light the moment they are switched on. This instantaneous production of light is achieved by the use of electronic ballasts. Ballast is a device which controls the starting voltage and the operating currents of lighting devices built on the principle of electrical gas discharge. It refers to that part of the circuit which limits the flow of current through the lighting device and may vary from being a single resistor to a bigger, complex device. In some fluorescent lighting systems like dimmers, it is also responsible for the controlled flow of electrical energy to heat the lamp electrodes.
Where there’s smoke, there’sfire and we usually don’t amuse ourselves with the idea of having a fire anywhere else other than a fireplace. So, we equip ourselves with an arsenal of early detection sensors that can help avert a potential disaster to life and property. One of the chief whistleblowers in this assortment of accident prevention devices is the smoke detector, which we can often see as round perforated plastic disks, fixed to the ceilings of offices and homes. A smoke detector, in all its simplicity, detects smoke in its surroundings and sounds an alarm. These are one of the most important safety devices in an establishment especially in homes, where it is one of the few sensors which can provide safety 24×7. The alarm issued may manifest itself as a Blinking LED, an Audio siren, or in case of establishments connected with a central monitoring station, an alert on the management screens in the control room.
If you have ever visited a video game parlour to play a video game, you definitely would have used a JOYSTICK. Originally invented for flight controllers and motion simulators, they gained acceptance in number of systems, ranging from video games to industrial systems. Millions of video game enthusiasts, crane operators, etc. would owe a debt of gratitude to the inventor of this wonderful device, a joystick, though the inventor of this device is not quite known. The word ‘Joystick’ was used first by Robert Loraine and was cited in the Oxford English Dictionary, though he didn’t invent the device. Mr. Robert Esnault – Pelterie is also mentioned to be an originator of this buzz word. A E George along with Jobling used a stick for the first time when they flew an aircraft and this stick gained popularity as Joystick.
The active RFID tags have their own source of power. They can transmit stronger signals over long distances and can operate in rugged environment for many years. Because of the on-board source of power they are larger in size and expensive. Then too Active RFID and Real-Time Location solutions (RTLS) are saving millions of dollars…
In old days when modes of transportation were not there, people used to walk to the places they wanted to reach. For transportation of goods, bullock carts, camels, horses, etc. were often used. All this was meeting the mobility requirements as the settlements were not too dispersed. With the rapid advancement in the development of tall building and public facilities, it became paramount to address the need to transportation of pedestrians and also of goods. With multi-storeyed buildings or large shopping complexes or airports, it is unreasonable to expect the user to travel across the buildings/ public facilities by means of walking alone, at least not in a timely manner. Towards this end, innovations sprung up facilitating movement of pedestrians as well as goods in large shopping malls, multi-storeyed residential buildings, airports and other public facilities.
Have you ever given a thought what happens when you throw or sell your old cell phone or personal computer? Where does it go? And how it affects the atmosphere? Electronic waste or e-waste are those electrical and electronic items that are no longer usable or have been replaced by the new generation version. Computers, cell phones, televisions, refrigerators, air conditioners, DVDs, iPods, copiers, and fax machines are common electronic products, which eventually turn to e-wastes. According to researchers nearly 75 percent of old electronic products are dumped in storage because of the uncertainty of how to manage these materials. Although many of these materials can be reused, refurbished, or recycled but unfortunately they are not, thus making the electronic discards as one of the fastest growing segments of world’s waste stream.
Zigbee is a low power spin off of WiFi. It is a specification for small, low power radios based on IEEE 802.15.4 – 2003 Wireless Personal Area Networks standard. The specification was accepted and ratified by the Zigbee alliance in December 2004. Zigbee Alliance is a group of more than 300 companies including industry majors like Philips, Mitsubishi Electric, Epson, Atmel, Texas Instruments etc. which are committed towards developing and promoting this standard. The alliance is responsible for publishing and maintaining the ZIgbee specification and has updated it time and again after making it public for the first time in 2005. Most of the recent devices conform to the Zigbee 2007 specifications has two feature sets– Zigbee and Zigbee Pro. The manufacturers which are members of the Alliance provide software, hardware and reference designs to anyone who wants to build applications using Zigbee.
When we start reading about radar, we come across various terms which are explained differently. There are various kinds of Radar classified in different ways. This article explains the various radar types in a lucid manner. A Primary Radar transmits high-frequency signals toward the targets. The transmitted pulses are reflected by the target and then received by the same radar. The reflected energy or the echoes are further processed to extract target information. Secondary radar units work with active answer signals. In addition to primary radar, this type of radar uses a transponder on the airborne target/object. The secondary radar unit transmits and also receives high-frequency impulses, the so called interrogation. This isn’t simply reflected, but received by the target by means of a transponder which receives and processes. After this the target answers at another frequency.