3. Inductors

Same as the coil used in the previous notes. The Inductor is a coiled conductor usually a copper wire. From the circuit below, an Inductor is connected across a DC voltage source. The current flows across the Inductor coil, and a Magnetic field is generated around the Coil.


This generated Magnetic field forces the current from changing in the circuit even when the voltage supply is shorted. This was discovered by “Emil Lenz” and is called Lenz Law. 

The direction of the Magnetic field and Current are as shown below, It is determined by the right Hand Rule where the thumb points the direction of the current and the folded fingers points the direction of the Magnetic Field. So inductors store current in the form on Magnetic Field. 

The Inductor maintains a constant flow of current through it. Generated Magnetic field forces this to happen. If a switch is introduced in the circuit as shown below.

From the circuit even when the Voltage source is OFF the current still flows in the circuit due to the inductor. For an ideal wire with “0” Resistance, the current flows forever in the loop. In a real case the duration of the current flow depends on the resistance of the wire and the inductance of the Inductor. If an LED is introduced in the circuit the LED glows momentarily even if the Voltage source is turned off. In a steady state condition the Inductor acts like a normal short cable.

No matter what the resistance on the cable is, the inductor will force to maintain the current, be it for a very short time. This results in generating very high voltages when the connected Resistor has a very high Resistance. This is the reason why the Inductors are used in high voltage generating circuits like “Boost converters”.

The inductance of an Inductor increases with increase in N- Number of turns or A- Area of the coil or Permeability of the core and decreases with increase in l- Average length of the coil.  

L : Inductance (Henry, H)

N: Number of turns

u:  Permeability of the core

l: Average length of the coil 

A: Area of the coil

As the Inductance (L) increases the Voltage (v) across will increase. The relation between L and v is as below, Voltage is the Inductance (L) times the rate of change of Current (di/dt).

2. Grounding in AC supply

Household equipments power cord usually has 3 terminals Neutral, Line and Ground. For a 3 phase circuit, circuit below shows Line and neutral. 

3 Phase supply is used for a long distance transmission. Houses usually get single phase and a limited number of 2 phase outlets for high demanding Electrical loads. 

Voltage across the two phases(two coils) will be double the voltage across the single phase(Single coil).

The main purpose of the Neutral cable is to send the current difference back to the source, “The Difference”- because two loads are connected at the same time. 

As Kirchhoff Current Law (KCL) says the net current flowing into the Node is equal to the total current coming out of the Node.

When both loads are equal, same current will be drawn i1=i2. In that case we do not require a Neutral wire to send back the difference current back to the source. This condition is called “Balanced Circuit”. This balanced condition doesn’t apply to a household with multiple different loads. The Unbalanced Condition occurs with an unequal loads are present.


The above circuit is already complete with Line and Neutral. 

What does ground do here?

Well, the ground protects from any short or dangers caused when a Line connection is exposed. The current chooses a lower resistance path to travel and ground is made with very low resistance material.

Where is it connected?

the ground connection is connected to the chassis of the load or any other susceptible spots closer to the “Line”. Because when a bad Line wire touches the chassis, the current chooses ground path and saves from danger.

As shown in the circuit above. When the neutral connection is connected to Ground, it reduces the risk of the Line wire touching the Neutral. When Neutral touches Line, the current chooses lower resistant Ground wire and eliminates the risk of shorting Line and Neutral.

1. DC/AC(1 Phase and 3 Phase) Supply

DC Supply

DC is straight forward. In a DC power supply, the current flow only in one direction, between negative Cathode to positive Anode. When any load (like a resistor or an LED) is connected across a battery, the current flows through the load and the load uses the current flow. In case of a resistor heat energy is released. For an LED light is emitted. 

Single Phase AC Supply

Flow of electric current in the wire generate Magnetic field around the wire and vice versa, current is generated in the wire when a magnetic field is introduced. When a magnet is moved in a coiled wire with multiple turns, a current is generated in the coil. Instead of using a permanent magnet, electromagnet can be used with varying magnetic field to generate more current.

When a magnet is rotated closer to a coil, at the point of strongest field a maximum current Is generated, the current gradually decreases to 0 and finally goes to minimum negative current. This cycle resembles a sine wave, and this cycle happens 60 times in a second (Frequency)~ 60Hz AC. It is 60Hz in the US and is 50Hz in Europe. It varies with what each country decides.

A coil can hold more electromagnetic field compared to a single wire. As the number of turns in the coil increases the electromagnetic field increases, this generate more current. This back and forth Alternating flow of current due to Electromagnetic field is called Alternating Current (AC).

This is how a single phase AC works. 

Three Phase AC Supply

Just like Single Phase, Assume an Electromagnet at the center and if this time 2 more coils be placed with the initial coil at 120 degrees with respect to the first coil. It will be 3 phase AC supply.

Why 3 Phase? When 3 loads need power at the same time, instead of using 3 different sets of transmission cables, a 3 phase AC supply is used.

To close the circuit with three phases, a Neutral connection should be connected. But when all three loads are equal, the net current at the node will be “0”. So for a Balanced load condition, there is no Neutral Line.

To be continued…

Two years of blogging!

That’s right, its been 2 years and I am not bored yet! I have started this blog on 4th, April, 2015, with zero expectations. Probably this is one of the very few things I did consistently for so long. Two years!! When I look back, I can’t tell about you, but I have become more “informatic”. I got to know a lot about blogging. I have started a self hosted blog 6 months ago, DAMN!! There was actually a lot to know before and after creating a self hosted blog.

Very recently, on 26th march 2017, I got the approval of Google AdSense!! And there is a big back story for it, to understand that just compare this WP hosted blog (https://informaticcoolstuff.wordpress.com/) and the self-hosted blog (http://informaticcoolstuff.in/).

Exactly a year ago, I wrote an article to celebrate one year of blogging, here’s the link to it One year of blogging., also an article, when I have reached my 100 articles count (!00th article with 100 fellow bloggers.) and an article on getting 50 wordpress followers on my blog (50 followers on wordpress.), right now I have 341 wordpress followers on this blog and 118 followers on self-hosted blog… That’s quite a long and fun journey. When i read those previously mentioned articles, I can clearly see what I have been doing. I mean, one article containing all that i did till that article… Sounds great right! Like “!00th article with 100 fellow bloggers” article contains almost all the work i did untill that article.

Ok, now let me give you all my favourite posts I did after the article “One year of blogging“. Before that, let me tell you why I do this kind of post… I celebrate any special milestones on my blog with all my favourite articles at one place.

I guess you wouldn’t be able to read all of those article completely, so, let me thank all the readers for reading my articles and for all their constant support. All the bloggers in this, so called “blogospehere” are amazing and inspiring.

Here’s are those article, ENJOY reading…

!00th article with 100 fellow bloggers.

Future of batteries

Complete story of “Nokia”!

Flying windmills!

what is E-Paper? How it works?

Solar Panel! How does it work?

My new self-hosted blog!

Machines that never stop!! Perpetual motion machines?

RFID! Is that the future of barcodes?


What is “BIG” data?

Iris Scan vs Retina Scan…

What is Gravitational lensing?

Computer Part-2. Processors!! What does i3,i5,i7 mean?, Computer! Part-1

Deep web and dark web??


Light bulbs! History and science…

Science of Muscle building!

Space Elevator! Possible?

What’s your speed right now?

Science of becoming Batman!!!

“WIND” Where it comes from?


Live forever “Frozen”(Cryonics)!

Misconceptions about tides! What really causes tides?

What’s Encryption? And what’s Quantum Cryptography?

Spherical Tires!!!








Future of Batteries

Over decades, we have seen a lot of improvements in almost all forms of technologies, one of the most noticeable part, which has no change since so long is “energy storage device” called “battery”. If you look at the technological industry, all developments are being done to use the energy contained in the batteries efficiently. But on the market we didn’t experience any change, when it comes to batteries, only the components that use batteries are made efficient towards energy consumption.

If new technologies rise, which can make energy storage better, then we don’t have to compromise on other components in a device due to batteries. For example the size of the device increase due to batteries, explosions of the batteries  can be avoided if the batteries won’t contain liquid in it(like, we use lithium, which explodes when moisture comes in contact).

Battery is that which stores chemical charge and converts it into electricity. Every battery has a cathode(+), anode(-) and an electrolyte. Cathode wants electrons, anode gives electrons and an electrolyte is that which helps ions to move between anode and cathode. This flow of electrons create electricity. Over the years we have found various ways of creating and storing electricity, like electricity from a lemon, banana etc… Most of those works on the above concept.

▪      A lot of research is being done on this particular topic, but most of those alternatives don’t have sufficient potential to get commercialized. Few alternatives that can be expected on the market soon are:

▪      Graphene  Super-capacitors.

▪      Solid state batteries.

Before getting into Graphene super-Capacitor, let’s see what are super capacitors and  capacitor s are!


▪      Basically a capacitor charges and discharges quickly. A basic capacitor usually consists of two metal plates, separated by an insulator (like air or a plastic film). During charging, electrons accumulate on one conductor and depart from the other. One side gains a negative charge while the other side builds a positive one. The insulator disturbs the natural pull of the negative charge towards the positive one, and that tension creates an electric field. Once electrons are given a path to the other side, discharge occurs.

Super capacitor:

▪      Supercapacitors also contain two metal plates, two electrodes are coated with a porous material known as activated carbon. They are immersed in an electrolyte made of positive and negative ions dissolved in a solvent. One plate is positive and the other is negative. During charging, ions from the electrolyte accumulate on the surface of each carbon-coated plate. Supercapacitors also store energy in an electric field that is formed between two oppositely charged particles, only they have the electrolyte in which an equal number of positive and negative ions is uniformly dispersed. Thus, during charging, each electrode ends up having two layers of charge coating (electric double-layer).

Graphene supercapacitor:

▪      Graphene is a thin layer of pure carbon, tightly packed and bonded together in a hexagonal honeycomb lattice. It is widely regarded as a “wonder material” because, it is the thinnest compound known to man at one atom thick, as well as the best known conductor. It also has amazing strength and light absorption traits and is even considered ecologically friendly and sustainable as carbon is widespread in nature and part of the human body.

▪      It is often suggested as a replacement for activated carbon in supercapacitors, in part due to its high relative surface area, which is even more substantial than that of activated carbon. The surface area is one of the limitations of capacitance and a higher surface area means a better electrostatic charge storage. In addition, graphene based supercapacitors will utilize its lightweight nature, elastic properties and mechanical strength.

▪      Graphene  Super-capacitor  has advantages of both Li-ion battery and a capacitor. Fast charging of a capacitor and the slow discharging of a battery can be obtained in a super-capacitor.

Solid state super capacitor:

▪      Almost all the batteries we use have a liquid or a gel in them. Now, when it comes to solid state batteries, the liquid or the gel portion is replaced with a solid. This can avoid battery explosions completely.

▪      The main difference between Li-ion batteries and solid state batteries is that the former uses a liquid electrolytic solution to regulate the flow of current, while solid-state batteries opt for a solid electrolyte. A battery’s electrolyte is a conductive chemical mixture that allows the flow of current between the anode and cathode.

How Solid state super capacitor works?

▪      solid state batteries use redox reactions to store and deliver energy. Oxidation occurs at the anode, reduction occurs at the cathode and the battery is able to use this phenomenon to store energy (charge) and release it (discharge) as necessary. During discharge, ions travel through an ion-conductive solid matrix instead of the ionic salt saturated solvent state of typical liquid electrolytes.

▪      Solid state electrolytes are fast ion conductors solids that allow ions to move freely throughout the solids crystalline matrix. Fast ion conductors are best thought of as a material that lies between crystalline solids that possess a regular structure with fixed ions and structure-less liquid electrolytes with freely flowing ions. Solid electrolytes often come in the form of gels, glasses and crystals with novel internal structures. In solid state batteries, solid electrolytes must meet a combination of high ionic conductivity, low internal resistance and high electronic resistance. The higher the ionic conductivity is the better the power density and the lower the internal resistance of the battery. The better insulating the solid electrolyte is to electrons, the lower the self-discharge rate and the higher the charge retention. Choice of solid electrolyte depends on the chemistry of the battery, and the ions available for conduction. In the case of lithium ion solid state batteries, a solid electrolyte like LiI/Al2O3 is an excellent Li+ conductor.


Commercial use:

The concept of solid state batteries are around for so long now, but the technology is still in research grounds.

Many technological industries are working in this new technology. It was old that, samsung is working on this.

There is a company called Sakti3 in Michigan, exclusively working on solid state batteries. A British electronics giant Dyson invested millions of dollars on Sakti3. Not only that, so many other companies also showed interest and invested millions of dollars. This clearly shows how important  this  could become.


▪    So, with this I conclude that, very soon we might see a change in the way we treat and use technology interms of energy consumption. The graphene super-capacitors and solid state batteries are not the only ways to  achieve these advantages, there are plenty of technologies under research. In my view these two are the closest to the market.










Complete story of “Nokia”!

Nokia is back in the game with it’s all new flagship mobile phone! So, this would be the correct time to know the rise, fall and rise of this most valuable brand “Nokia”. Nokia, one of the most successful mobile company of late 1990’s and early 2000’s. First mobile phone of most of you guys reading this might be from Nokia. But what happened to this company later on? Why this mobile giant back then, isn’t on par with it’s competitors later on? Let’s see the complete story from the start.

The company was started in the year 1865, but back then the company wasn’t a mobile manufacturing company. A mining engineer Fredrik Idestam started his first wood pulp mill in Sothern Finland and his second mill at the bank of the river Nokia. That’s how the company got it’s name. In the coming years, nokia started manufacturing rubber, tvs, wires, tires etc…In 1960’s at the time of cold war, there was a tension situation going on and the Finland government wanted military research on radio telephone communication. There you go, the company Nokia got the opportunity to do exactly that.


By 1970’s the company started building car telephone network. Nokia also make the car communication devices reliable and small. By 1985, it expanded globally. In 1987, Nokia introduced its first mobile phone , it’s called Mobira Cityman 900. In 1992 Jorma Jaakko Ollila  became the CEO of Nokia, this was the golden time for the company. Jorma Jaakko Ollila only concentrated on mobile manufacturing and closed all other projects.

No company was so good as Nokia in making mobile phones, exactly the way they are ment to be. In 1992 the company introduced first ever GSM mobile phone to the world(Nokia 1011) . After that, in 1994 they introduced a mobile phone called Nokia 2110, which isn’t bulky as other contemporary phones were back then. Also it was the first phone to display missed calls, send and receive text messages.

In 1997, they released Nokia 6110, which gave the most loved, played and  fun game “the snake game”. It was the first phone ever to showcase that game. By 1998, nokia has become the number one mobile phone manufacturer. Until 2003, Nokia was unstoppable. It make 3g phones, camera phones etc… After 2003 Nokia started experimenting on design and all.


In 2006, Nokia’s management changed. And N95 phone was released, which was a very good phone. But not as good as the phone released by Apple Inc. “The iPhone” with a capacitive full touch internet enabled mobile phone. Before the Nokia recovers from a big blow from Apple, Google released its mobile phone software “Android”. To compete these two devices, nokia released its 5800, which was good, but again couldn’t compete.

In 2008, in order to compete with other manufacturers, Nokia started working on software using its Symbian team and meego team. There was competition within the company, between Symbian and meego. Which inturn lead to delays. And the other wrong step took by the management of nokia was, denying to work with Android.

In 2010, Elop became the CEO. Elop was a former employee of Microsoft. They did released some bunch of very good phones at his time, but there was no team work at all and not many apps in their software meego when compared to the android and app store. So, meego was closed in 2012. In 2011 Nokia make a partnership with Microsoft. Later on a lot of phones powered by Microsoft were released. Even the partnership with Microsoft didn’t help nokia to see a big success. It was like the end of glory days for Nokia, Microsoft took over the mobile manufacturing  division. Elop, from the CEO of nokia, went on joining Microsoft again. This move of Elop raised a lot of questions.


Rise again:

Now, in 2017 Nokia is back after the contract with Microsoft. Now, Nokia can manufacture devices with its own brand. Recently Nokia has announced a new line of smart phones, which are amazing. I personally feel, Nokia might gain its charm back. I am looking forward to this years MWC ( mobile world congress) on February  27th.


Thanks for reading, let me know your thoughts. And here’s my other blog informaticcoolstuff.in please do read it too…



Flying windmills!

“Energy”, don’t know how many times we use this word, but we surely use energy everyday. By now, we know what renewable energy sources are( if not go ahead and click here Renewable).

One of the most effective renewable sources of energy is wind energy, till now we have seen only the windmills on the ground producing energy. But, here are the new ones that are situated above the ground so called “Flying Windmills”.

So, what is the reason to put the windmills above the ground? Well… Higher altitudes offer upto five times stronger winds that are also consistent.

This thing flies with the help of helium filled shell. The airborne wind turbine will be held steady by making use of strong tethers which will also transfer the electricity generated to ground. And Flying windmills are actually tested!

Ben Glass, is the one who came with this idea. Learn more about these flying windmills from the video below.

And please do visit informaticcoolstuff.in


Top-5 tech at CES 2017 (Consumer Electronics Show).

CES is here. My personal favourite… In case you didn’t notice, CES 2017 is the 50th consumer electronics show! Over the years, most of the new technologies and gadgets that rule the rest of the year originates from CES. Of course MWC(Mobile World Congress) and WWDC(World Wide Development congress) awesome too and also plays a major part. For now let’s talk CES, it is held every year in January.

Here’s my favourite tech on CES!

In my view, this year CES was all about VR (Virtual reality), AR (Augmented reality), AI(Artificial intelligence), IOT(Internet of things), TVs, Self driving cars and a lot of smart phones related stuff! Most of the gadgets introduced in CES 2017 falls in one of these categories.

  1. The displays are really crazy this year. LG OLED W-Series  is my personal favourite maxresdefault-1-35

Just look at it! It is so thin that, it just sticks to the wall like a poster… Well, the speaker for the TV are separate.

All the other displays are mind blowing too… The TV by Samsung, Sony, Amazon etc…

2. The processors, the Qualcomm’s all new Snapdragon 835 processor was introduced. Intel’s new Lake 7th generation intel core processor.

3. The smart bed called “Sleep Number 360”, this was actually cool. This intelligent bed does so much…

Look at it for your self…

4. Obviously a bunch of new laptops and smartphones. Blackberry’s new smart phone “BlackBerry mercury”, this has an amazing built. Asus’s new AR smart phone, this comes with snapdragon 821, Google’s tango technology and the first phone to come with 8 GB RAM.

5. Razer’s Project Ariana is an extension of the gaming company’s Chroma lighting setup. Rather than just brightening up a keyboard, this 4K projector expands your game outside of a monitor. It’s pretty trippy, and unlike Microsoft’s similar IllumiRoom concept, Ariana will hopefully be a shipping product by year’s end. The Razor’s Roccat mouse and also the 3 monitors containing laptop…


These are just a few awesome tech in CES 2017. There are hundreds of more gadgets and futuristic ideas out there, I cant cover all those in one single article. Go ahead check out CES 2017 right away..

And here is my another blog http://informaticcoolstuff.in/ . Please do visit this blog too!

Let me know your favourite thing in CES 2017…

Happy new year!

It’s been so long since I wrote anything. But, I am back now. I will try to post regularly from now on. As today is the first day of this new year 2017, I would like to put all my favourite articles I wrote in the last year. Of course, I like all those I wrote. But what I mean was, all the articles that might interest you are put at one place.

Here we go…

  1. Parallel universe
  2. How we see in 3d
  3. Mass of trees come from
  4. Internet of things
  5. Gravitational waves
  6. Flying windmills
  7. What is supernova?
  8. Flash science
  9. Gravity lights
  10. Move back and forth in time
  11. Stars really twinkle?
  12. General and special relativity
  13. Does cell phones cause tumor
  14. Self cleaning nano tech
  15. One year of my blog!
  16. Spherical tires
  17. Encryption
  18. What really cause tides
  19. Cryonics
  20. Where does wind come from?
  21. Science of becoming batman
  22. What’s your speed right now?
  23. Hypnosis!
  24. Computer part-1
  25. Space elevator
  26. Science of muscle building
  27. Deep web and dark web
  28. Computer part-2; Choosing processors!
  29. Gravitational lensing
  30. Iris scan vs retina scan!
  31. Antimatter!
  32. RFID tags
  33. My new self hosted blog
  34. working of Solar panels.
  35. What is e-paper and how it works?

Wow, I am actually very happy that most of the article I wrote this year made it to this list. Now, I have 323 wonderful followers on my blog with 180 articles Usually for any special days like making 100 followers or  200 followers or having done one year in blogging or anything that has to do with blogging, I list out all my favourite articles at one place.

So, here are all those posts I did on those “special days”…

50 wp followers!

100th article with 100 followers!!

One year of blogging!!!

My new selfhosted blog!!!!

Here is the link to my selfhosted-blog ” informaticcoolstuff.in“. Please do visit and support as you guys always did!

what is E-Paper? How it works?

E-Paper or Electronic Paper Display is pretty much similar to an ordinary paper. Then why E-Paper??

There are a lot of advantages with E-Paper, when we compare with ordinary paper ink, it can be electrically refreshed and written upon millions of times.

E-Ink takes advantage of interactions between computer processors and charged black and white particles. Unlike traditional displays like LCDs, LEDs etc… These E-Papers have an advantage of more readability, are flexible and these use very low power .

To get all these advantages together there are a few compromised features like low touch screen capability and less responsive than comparable LCD screen devices. E-Paper manufacturing companies are working to overcome these disadvantages..

The Electronic Paper technology is very futuristic and has a high potential in reducing the usage of paper indirectly saving the environment by not using thousands of trees for the manufacture of paper. E-Paper only use a limited power and can store thousands of books in a single portable device. This means you almost have a whole library in your hand.

After knowing all these interesting and amazingly useful advantages, you must be curious to know about the working of this E-paper right!

Firstly, There are two popular companies manufacturing E-Paper “Electronic inks” – E Ink and “Xerox”.

The e-ink looks very similar to normal ink but it has millions of tiny microcapsules also known as cavities, and are filled by an ink substance. There are pigmented chips or balls there balls are actually the colours that are displayed on the screen. Let’s say white and black. These ball are with a negative charge floating inside the microcapsule.  The ink would cover the entire page and the page is made out of some kind of ultra-thin plastic separated by cells that resemble the cells on graph paper.


These cells are like pixels on a computer screen and each and every cell is wired to the micro level electronics embedded in the page made of ultra thin plastic. Using the basic concept, positive attracts negative or unlike poles attract, these microelectronics would then be used to apply a positive or negative charge to the microcapsules to create the desired text or images. For example, let, all the black balls are negative and all white balls are positive, then when a positive charge is given then, as per the instruction the black balls appear on the screen accomplishing specified task of presenting an image or a number etc…

Likewise, when an electrical charge is applied to the microcapsules, the chips will either rise to the top or be pulled to the bottom. When pushed to the top, the chips make the capsules look white; when they are pulled to the bottom, the viewer only sees the dark ink. Patterns of white and dark can then be created to form words and sentences.

Even more colours other than white and black are also coming to E-paper. There are plenty of gadgets which take the advantage of E-paper like Yotaphone 2, Pebble smart watches, Amazon kindle and also there are many stores which use e-paper to display product prices and other information instead of LCD and LED screens…

This has a lot of scope for development in the coming years! Let me know what you think!