Category Archives: Newsworthy

What Are Proximity Sensors?

Those of you who use a mobile phone with a touch-screen may have wondered why items on the touch-screen do not trigger when you hold the phone to your ear while answering a call. Well, designers of mobile phones with touch-screen have built-in a feature that prevents a situation such as “My ear took that stupid picture, not me.” The savior in this situation is the tiny sensor placed close to the speaker of the phone, and this proximity sensor prevents touch-screen activity when anything comes very close to the speaker. That is what happens when your ear touches the screen as you are on a call, but does not generate any touch events.

So, what sort of proximity sensors do the phones use? Well, in most cases, it is an optical sensor or a light sensing device. The sensor senses the ambient light intensity and provides a “near” or “far” output. When nothing is covering the sensor, the ambient light falling on it makes it give out a “far” reading, and keeps the touch-screen active.

When you are on a call, your ear covers the sensor, obstructing the device to see ambient light. Its output changes to “near” and the phone ignores any activity from the touch-screen, until the sensor changes its state. Of course, the mobile phone considers more complications such as what happens when the ambient light falls very low, but we will discuss more on different types of proximity sensors instead.

Different types of proximity sensors detect nearby objects. Usually, the proximity sensor is used to activate an electrical circuit when an object either makes contact with it or comes within a certain distance of the sensor. The sensing mechanism differentiates the types of sensors and these can be Inductive, Capacitive, Acoustic, Piezoelectric and Infra-Red.

You may have seen doors that open automatically when you step up to them. When you are close to the door, the weight of your body changes the output of a piezoelectric sensor placed under the floor near the door triggering a mechanism to open the door.

Cars avoid bumping into walls while backing. The proximity sensor (a transmitter and sensor pair) used here works acoustically. A pair is fitted on the backside of the car. The transmitter generates a high frequency sound signal and the sensor measures the time difference of the signal bounced back from the wall. The time difference reduces as the car approaches the wall, telling the driver when to stop.

Computer screens inside ATM kiosks and the screen on your mobile are examples of capacitive proximity sensors. When you put a finger or a style on the screen, the device detects the change in the capacitance of the screen. The device measures the capacitance change in two directions, horizontal and vertical, or in x and y directions, to pinpoint the exact location of your finger and operate the function directly underneath.

When a security guard checks you out with a wand, or you walk through a metal detector door, the guard may ask you to remove your watch, coins from your pocket and in many cases, even your belt. The reason is the wand or the door has an inductive proximity sensor that will trigger in the presence of metals (mostly made of iron or steel).

Finally, the fire detector in your home or office is a classic example of a proximity sensor working on Infrared principles. Level of infrared activity beyond a threshold will trigger the alarm, and bring the fire brigade rushing.

How Does the Touch Screen on a Mobile Phone Work?

The mobile phone is an amazing piece of work. Earlier you had to press buttons, now you just touch the app on your screen and it comes to life. You can even pinch your pictures to zoom in on a detail or zoom out to see more of the scene. The movement of your finger in the screen causes the screen to scroll up, down, left or right.

The technology behind this wizardry is called the touch-screen. It is an extra transparent layer sitting on the actual liquid crystal display, the LCD screen of your mobile. This layer is sensitive to touch and can convert the touch into an electrical signal, which the computer inside the phone can understand.

Touch screens are mainly of three different types – Resistive, Capacitive and Infrared, depending on their method of detection of touch.

In a resistive touch-screen, there are multiple layers separated by thin spaces. When you apply pressure on the surface of the screen by a finger or a stylus, the outer layer is pushed into the inner layers and their resistance changes. A circuitry measuring the resistance tells the device where the user is touching the screen. Since the pressure of the finger or the stylus has to change the resistance of the screen by deforming it, the pressure required in resistive type touch-screens is much more than for capacitive type touch-screens.

Capacitive type touch-screens work on a principle different to that of the resistive touch-screens. Here the change measured is not in terms of resistance but of capacitance. A glass surface on the LCD senses the conductive properties of the skin on your fingertip when you touch it. Since the surface does not rely on pressure, the capacitive touch-screens are more responsive and they can respond to such gestures as swiping or pinching (multi-touch). Unlike the resistive type screens, the capacitive screen will only respond to touch by a finger and not to stylus or a gloved finger, and certainly not to fingers with long nails. The capacitive touch-screens are more expensive and can be found on high-end smartphones such as from Apple, HTC and Samsung.

As the screen grows larger, such as for TVs and other interactive displays such as in banking machines and for military applications, the resistive and capacitive type technologies for touch sensing quickly become less than adequate. It is more customary to use infrared touch screens here.

Instead of an overlay on the screen, infrared touch screens have a frame surrounding the display. The frame has light sources on one side and light detectors on the other. The light sources emit infrared rays across the screen in the form of an invisible optical grid. When any object touches the screen, the invisible beam is broken, and the corresponding light sensor shows a drop in the signal output.

Although the infrared touch-screens are the most accurate and responsive among the three types, they are expensive and have other disadvantages. The failure rate is high because diodes used for generating the infrared rays fail often.

What is an oscilloscope and how does it work?

An oscilloscope enables the visual display of a voltage that varies with time. One of the two input points is generally connected to the chassis and grounded, but this is not always the case.

A probe, attached to the input port of the oscilloscope, is connected to the voltage source. Some oscilloscopes have two or more input ports. Oscilloscopes with multiple ports can enable simultaneous viewing of waveforms, say, at the input and output of a circuit, for comparison and measurement, etc.

Analog and Digital Oscilloscopes

The analog oscilloscope uses a Cathode Ray Tube, and is also called a Cathode Ray Oscilloscope. In an analog oscilloscope, a thermally heated electron gun emits electrons, and an applied DC voltage causes the electron beam to impinge upon a fluorescent screen as a bright spot. A control grid results in axial movement of the electron beam and controls the number and speed of electrons in the beam. The momentum of electrons impinging on the screen decides the brightness of the spot. Applying a more negative voltage causes fewer electrons to impinge and is used for intensity control. A variable positive voltage on the second anode adjusts the trace sharpness. On applying an input voltage, the electron beam deflects proportionately, creating an instantaneous trace on the screen.

If a voltage input is applied to the vertical deflection plates and the horizontal deflection plates are grounded, the spot on the screen moves only up and down. On interchanging the signal to vertical and horizontal plates, the spot moves from left to right. If two signals of same frequency and in synchronization are applied to the two pairs of deflection plates, a trace results. The bright spot must repeat the same trace at least 30 times a second for the human eye to see it as a continuous trace.
By contrast, a digital oscilloscope first samples the waveform, and converts it into a digitally coded signal by an analog-to-digital converter. The oscilloscope processes this digital signal to reconstruct the waveform on the screen. Storage in a digital format enables data processing even by connected PC’s. In this oscilloscope, stored data including transients can be visualized or processed at any time, a feature not available in analogue oscilloscopes.

Displaying a Waveform

Whereas in analog oscilloscopes, continually varying voltages are used, in digital oscilloscopes, binary numbers are employed and these correspond to the input voltage samples. An ADC or analog to digital converter changes the measured voltage into its digital information. A series of samples of the waveform are taken and stored, until there is enough to describe a waveform. The information is then reassembled to be shown on the Liquid Crystal Display.

Unlike an analog oscilloscope, which uses a time-base and a linear saw-tooth waveform to display the waveforms repeatedly on the screen, a digital oscilloscope uses a very high stability clock to collect the information from the waveform.

Types of Digital Oscilloscopes

There are three types of digital oscilloscopes and they are classified as digital sampling oscilloscopes, digital phosphor oscilloscopes and the digital storage oscilloscopes.

In conclusion
Oscilloscopes, both analogue and digital, are among invaluable measuring and diagnostic tools in the electronics industry with newer applications continuously evolving with innovations in technology.

Can capacitors act as a replacement for batteries?

It is common knowledge that capacitors store electrical energy. One could infer that this energy could be extracted and used in much the same way as a battery. Why can capacitors then not replace batteries?

Conventional capacitors discharge rapidly, whereas batteries discharge slowly as required for most electrical loads. A new type of capacitors with capacitances of the order of 1 Farad or higher, called Supercapacitors:

• Are capable of storing electrical energy, much like batteries
• Can be discharged gradually, similar to batteries
• Recharged rapidly – in seconds rather than hours (batteries need hours to recharge)
• Can be recharged again and again, without degradation (batteries have a limited life and hold increasingly lower charge with age, until they can be recharged no longer)

The Supercapacitor would thus appear to be one up on the batteries in terms of performance and longevity, and some more research could actually lead to a viable alternative to conventional fuel for automobiles. It is this concept that created the hybrid, fuel-efficient cars.

However, let us not jump to conclusions without considering all the aspects. For one, the research required to refine this technology would be both time and cost intensive. The outcome must justify the efforts in terms of both time and cost. The negatives must be carefully weighed against the advantages enumerated above, some of which are:

• Supercapacitors’ energy density (Watt-hours per kg) is much lower compared to batteries, leading to gigantically sized capacitors
• For quick charging, one would need to apply very high voltages and/or currents. As an illustration, charging a 100KWH battery in 10 seconds would need a 500V supply with a current of 72,000 Amps. This would be a challenge for safety, besides needing huge cables with solid insulation, along with a stout structure for support
• The sheer size of the charging infrastructure would call for robotic systems, a cumbersome and expensive set up. The cost and complexity of its operation and maintenance at multiple locations could defeat its purpose
• Primary power to enable the stations to function may not be available at remote locations.
Many prefer to opt for the traditional “battery bank” instead. The major problem of lead acid battery banks is the phenomenal hike in the cost of lead and the use of corrosive acid. Warm climates accelerate the chemical degradation leading to a shorter battery life.

A better solution, as often advocated, is to use a century-old technology in which nickel-iron (NiFe) batteries were used. These batteries need minimal maintenance, where the electrolyte, a non-corrosive and safe lithium compound, has to be changed once every 12-15 years. To charge fully, it is preferable to charge NiFe batteries using a capacitor bank in parallel with the bank rather than charging with a lead-acid-battery charger.

Though NiFe batteries are typically up to one and a half times more expensive, lower maintenance cost more than offsets the same over its lifetime.

To summarize, the Supercapacitor technology would still have to evolve in a big way before actually replacing batteries although the former offers a promising alternative to batteries.

image courtesy of eet.com

The Future of Cloud Computing

What is Cloud Computing?

Cloud Computing, an efficient method to balance between dealing with voluminous data and keeping costs competitive, is designed to deliver IT services consumable on demand, is scalable as per user need and uses a pay-per-use model. Business houses are progressively veering towards retaining core competencies, and shedding the non-core competencies for on-demand technology, business innovation and savings.

Delivery Options
• Infrastructure-as-a-Service (IaaS): Delivers computing hardware like Servers, Network, Storage, etc. Typical features are:
a) Users use resources but have no control of underlying cloud infrastructure
b) Users pay for what they use
c) Flexible scalable infrastructure without extensive pre-planning
• Storage-as-a-Service (SaaS): Provides storage resources as a pay-per-use utility to end users. This can be considered as a type of IaaS and has similar features.
• Platform-as-a-Service (PaaS): Provides a comprehensive stack for developers to create Cloud-ready business applications. Its features are:
a) Supports web-service standards
b) Dynamically scalable as per demand
c) Supports multi-tenant environment
• Software-as-a-Service (SaaS): Supports business applications of host and delivery type as a service. Common features include:
a) User applications run on cloud infrastructure
b) Accessible by users through web browser
c) Suitable for CRM (Customer Resource Management) applications
d) Supports multi-tenant environment

There are broadly three categories of cloud, namely Private, Hybrid and Public.

Private Cloud
• All components resident within user organization firewalls
• Automated, virtualized infrastructure (servers, network and storage) and delivers services.
• Use of existing infrastructure possible
• Option for management by user or vendor
• Works within the firewalls of the user organization
• Controlled network bandwidth
• User defines and controls data access and security to meet the agreed SLA (Service Level Agreement).

Advantages:
a) Direct, easy and fast end-user access of data
b) Chargeback to concerned user groups while maintaining control over data access and security

Public Cloud
• Easy, quick, affordable data sharing
• Most components reside outside the firewalls of user organization in a multi-tenant infrastructure
• Access of applications and storage by user, either at no cost or on a pay-per-use basis.
• Enables small and medium users who may not find it viable or useful to own Private clouds
• Low SLA
• Doesn’t offer a high level of data security or protection against corruption

Hybrid Cloud
• Leverages advantages of both Private and Public Clouds
• Users benefit from standardized or proprietary technologies and lower costs
• User definable range of services and data to be kept outside his own firewalls
• Smaller user outlay, pay-per-usage model
• Assured returns for cloud provider from a multi-tenant environment, bringing economies of scale
• Better security from high quality SLA’s and a stringent security policy

Future Projections and Driving User Segments

1. Media & entertainment – Enabling direct access to streaming music, video, interactive games, etc., on their devices without building huge infrastructure.
2. Social/collaboration – cloud computing enables more and more utilities on Face book, Linked-In, etc. With user base of nearly one-fifth of the world’s population, this is a major driving application
3. Mobile/location – clouds offering location and mobility through smart phones enable everything from email to business deals and more.
4. Payments – Payments cloud, a rather complex environment involving sellers, buyers, regulatory authorities, etc. is a relatively slow growth area

Overall, Cloud Computing is a potent tool to fulfill business ambitions of users, and with little competition on date, is poised for a bright future.

Is your anti-virus software really effective?

A popular concept floats around stating that anti-virus software simply does not work. Some sections of the press are known to propagate that the software products sold by anti-virus companies are rather ineffective in combating computer virus. Studies also influence these views on the efficacy of anti-virus software, such as the one conducted by a digital security agency in the USA. It infers that the high rate of virus growth on the internet outsmarts the bulk of anti-virus software commercially available. These software products fail to keep track of and provide adequate protection to computers against virus. Consequently, the effectiveness of these products is not commensurate with the cost of such software.

Some leading anti-virus providers have openly discarded these findings on grounds of ridiculously small sample sizes to be statistically correct, and declared the methodology used as inappropriate and unsound. They further consider the validation methodology – of simply examining the digital signatures – as poor and unscientific, not having run the study samples on live PC’s that such anti-virus software were actually supposed to protect.

The process of scanning signatures for malware detection is just one among several recognized methods of identifying the source of virus. Real anti-virus protection involves a lot more than that presumed in the aforementioned study. To be really useful, a complete suite of such methods must work in tandem, and that is the real safeguard against virus.

Consider a case of vehicle security, which could be a combination of an ignition lock, a door lock, gear lock, steering lock, immobilizer and a recent addition of GPS tracker, to name a few. Each of these provides a part of the protection using commercially available tools. The owner must decide the type and quantity of these he wants obtain and what he is willing to pay for them. A lopsided decision may defeat the very purpose of protection. It is like one installing a GPS tracker and an immobilizer in his car. A burglar may break the window glass and happily walk away with the expensive stereo, laptops and other valuables in the car, which the GPS tracker, or immobilizer may not be equipped to sense.

It is rather unjust to make a sweeping statement that anti-virus tools are no good in affording protection, without first deciding the level of security desired and having implemented solutions commensurate with such security. One needs to understand, with expert advice where necessary, the implications of using methods like firewalls, anti-phishing, anti-spam and so on, including what each can protect.

Another analogy to elucidate this concept is the performance of an orchestra, which does not depend solely on the violinist or the pianist, or even the entire range of musicians. Other important factors affect the performance, such as the conductor, the acoustics, the seats, the audience, and so on.

Irrespective of what popular opinion makes it out to be, if one is clear what one desires to protect and uses proper tools, it is very unlikely for one to conclude that anti-virus software serves no useful purpose.

Energy Harvesting – How & Why

What Is Energy Harvesting – Why Is It Needed?

The process of extracting small quantities of energy from one or more natural, inexhaustible sources, accumulation and storage for subsequent use at an affordable cost is called Energy Harvesting. Specially developed electronic devices that enable this task are termed Energy Harvesting Devices.

The world is facing acute energy crisis and global warming, stemming from rapid depletion of the traditional sources of energy such as oil, coal, fossil fuels, etc., which are on the verge of exhaustion. Not only is the global economy nose-diving, but the damage to the environment is also threatening our very existence. Natural calamities like earthquakes, tsunamis, droughts, floods, storms, etc., have become the order of the day. Economic growth is generating a spiraling demand for energy, goading us to tap alternative sources of energy on a war footing. Our very existence on the planet Earth is at stake, and we must find immediate solutions to meet the energy needs for survival.

Alternative Energy Sources Available

There are many, almost inexhaustible, sources of energy in nature. In addition, these energy forms are available almost free, if available close to the place where required. Sources include: Solar Energy, Wind Energy, Tidal Energy, Energy from the waves of the ocean, Bio Energy, Electromagnetic Energy, Chemical Energy, and so on.

Recent Advances in Technology

The sources listed above provide miniscule quantities of energy. The challenge before us is to gather the miniscule amounts and generate meaningful quantities of energy at affordable cost. Until very recently, this has remained an unfulfilled challenge.

Today, research and innovation has resulted in creation of more efficient devices to capture minute amounts of energy from these sources and convert them into electrical energy. Besides, better technology has led to lower power consumption, and hence higher power efficiency. These have been the major propelling factors for better, more efficient energy harvesting techniques, making it a viable solution. These solutions are considered to be more reliable and relatively maintenance free compared to traditional wall sockets, expensive batteries, etc.

Basic Building Blocks of an Energy Harvesting System

An Energy Harvesting System essentially consists of:

a) One or more sources of renewable energy (solar, wind, ocean or other type of energy)
b) An appropriate transducer to capture the energy and to convert it into electrical energy (such as solar cells for use in conjunction with solar power, a windmill for wind power, a turbine for hydro power, etc.)
c) An energy harvesting module to accumulate, store and control electrical power
d) A means of conveying the power to the user application (such as a transmission line)
e) The user application that consumes the power

With advancement in technology, various interface modules are commercially available at affordable prices. Combined with the enhanced awareness of the efficacy of Energy Harvesting, more and more applications and utilities are progressively using alternative sources of energy, which is a definite sign of progress to effectively deal with the global energy crisis.

Optional addition of power conditioning systems like voltage boosters, etc., can enhance the applications, but one must remember that such devices also consume power, which again brings down the efficiency and adds to cost.

Parental Control V-Chip – What is it and how does it work?

Parents are concerned over the type of programs their children watch on the television and would like to exercise their control. They do not want their children watching programs with excessive violence or sexual content. Since it is not possible to be always present when the children are watching TV, it is best to have a device automatically detecting the type of program coming through, and blocking it if it is objectionable.

All television sets made and sold in the US after 1999 have a special electronic chip built in and this is the V-chip. This allows parents to select the level of violent programs, which children can watch in the home. This also means that all TV programs contain a rating transmitted along with the program, which the V-chip can detect.

The FCC defines the ratings as –

TV-Y – Suitable for all children, with no violence and no sexual content
TV-Y7 – Suitable for children aged seven and over
TV-G – Suitable for general audiences, with no violence, no sex and inappropriate language
TV-PG – Parents to exercise their own discretion
TV-14 – Suitable for children above 14 only, with some violence and sex
TV-MA – Suitable for mature audiences only and may contain sexual situations and/or graphic violence

A parent can program the V-chip with a specific rating, and the chip will block all programs or shows above that rating. For example, if you have programmed a V-chip for a TV-G rating, it will allow all programs with a rating of TV-G, TV-Y7 and TV-Y, and will block all the rest.

All television programs transmit synchronizing signals, which allow a proper build-up of the picture on the screen. The electron beam painting the picture on the screen starts to sweep from the top left corner to the right edge of the screen, turns itself off, retraces itself to the left edge and sweeps again to the right edge, moving down a tiny bit in the process, until it has covered the entire height of the screen. The beam then returns from the bottom right hand corner of the screen to the top left hand corner and the whole process repeats. The vertical and horizontal retrace signals transmitted along with the TV program control all this.

As the signal returns from the bottom of the screen to the top, it follows a number of horizontal retrace lines. The twenty-first line of the horizontal retraces has data embedded in it as specified by the XDS standard. This includes captioning information, time of the day, ratings information and many others.

The V-chip is capable of reading this line 21 data, extracts the rating’s information and compares it with the parent’s allowed rating. Accordingly, the chip lets the signal pass through or blocks it.

The V-chip in the television works in conjunction with the cable box and/or the VCR. You can either utilize the V-chip or turn it off.

Is it safe to buy gray market electronic components?

What Are Gray Market Electronic Components – And Are They Safe To Buy?

Chances are the low-cost rechargeable batteries that you ordered over the net failed after one or two cycles of operation. A closer inspection would have revealed the batteries were already past their shelf life when you received them. Welcome to the world of gray market electronic components, which currently forms about 6 to 8% of the total electronic components market, and makes up as much as $60 billion dollars’ worth.

Not only outdated components, even parts rejected (and preferably destroyed) by manufacturers, find their way in the supply chain. It is only after soldering the components and sending them for testing does the realization sinks in that they are not genuine. In the $300 billion semiconductor industry, such bogus components have an annual impact of up to $20 billion.

Apart from this, the gray market is also a known issue for unauthorized sale of new and branded products diverted from the authorized channels of distribution. The gray market not only makes the high-tech companies suffer, it also affects negatively consumers and other end-users of technology, such as the military and the defense. Products advertised as new and authentic could in reality be refurbished after use. They could even be counterfeit. Using counterfeit or non-conforming parts could have significant effects on the performance of the product. In the case of defense and military, these effects could also be catastrophic.

Components Direct recently conducted a study for a leading semiconductor supplier. They found over 90 million units of the products, both analog and digital devices, with over 7,000+ part numbers, were floating in the gray market. Over 80% of the products were in the Asian gray market, and 8% appeared in the EMEA (Europe, the Middle East and Africa) and North America. More than 29% of their gray market product had date codes of less than one year, although the product age spanned several years. Nearly 15% of these products had date codes more than 11 years old.

This demonstrates that no end consumer is immune to unauthorized products, irrespective of whether you are a military sub-contractor searching for obsolete components, or an OEM (Original Equipment Manufacturer) looking for new products.

As the chain of supply has numerous potential points of entry, and the ability to trace the path of the product flow remains limited. This makes the gray market problem a prevalent one in most product categories. The multiple points of entry provide unlimited opportunities for unscrupulous individuals, partners or counterfeiters.

The impact of the gray market is significant and long-term. This affects the revenue, cost, brand reputation, liability and risk of the entire chain of supplies. After sales support for the product may be non-existent or it may affect the company’s profitability to maintain support since no one has paid the applicable support. This also affects the end-user operationally and financially, and it may tarnish the manufacturer’s reputation because of the lowered satisfaction of the end-user with the brand

So how do you protect yourself? Look for component suppliers that are stocking distributors. Take to the search engines to see if there are reports of the supplier having supplied bad or counterfeit parts in the past. If you are unsure, buy a sample and have it tested. While there are some scammers out there, there are also many honest and hard-working small businesses that deserve your business.

Tracking sleep, activity & food – the Jawbone UP app

Imagine being able to track every calorie you burn, every calorie you consume and every minute you are sleeping? We came across the Jawbone UP and are just amazed at the capabilities this app possesses. It needs to be coupled with the UP wristband to function (available on their site for about $129 or on ebay for less than $100). The app is compatible with iPhone and Android.

Here’s some of the amazing features:

Sleep and nap tracking – it tracks your sleep including the amount of light sleep vs deep sleep.

Power Nap – need a power nap? UP will let you get one in and wake you up after the perfect amount of sleep is achieved (26.5 minutes according to the UP web site).

Smart Alarm – UP will wake you up at the best possible time in your sleep cycle – this will help you feel more awake and refreshed.

Food and Drink Tracker – helps you keep track of what you eat and drink to get the whole picture of your health.

Activity Tracker – UP tracks every calorie you burn, every activity you do.

There are many more features (like a mood tracker) that you can also monitor but the bottom line is that this system helps you keep track of every bit of your lifestyle and delivers information to help you live a healthier life and encourages you to keep moving forward. Sound interesting to you? We’re hooked! We love the idea and are placing our order today for our first one. We’ll keep you posted on our experience with it.