Strength of Electric Current

I never had a good feel or the measure of the strength of electric current. Had questions like what’s the power of a current when they say 1A, 100 A or say 200 mA and so on. You don’t get a picture

I was reading Floyd’s Electrical Fundamentals this morning. Very well illustrated book for electrical engineers.
It has a section on Electric shock.

Electric shock is actually caused by the flow of electric current and not voltage.
But for electric current to flow we should have a voltage and resistance.

Our body has a resistance typically from 10K ohm to 50k ohm
If you touch a voltage source of 90 V, you would receive 9 mA of current, which is dangerous.

1 mA - Slight perception
10 mA – mild shock
20 mA – severe mild shock
200 mA – Could be fatal if it lasts for 5 seconds
4 A – Heart paralysis ( which 4000 mA )
5 A - Could burn the tissue and could be worse.

So when you look at ratings on the electrical appliances next time, hope you’ll have some idea of how strong the current is.

Huttadalli Hutta

My first ever theatrical experience in my adulthood. Went to Ranga Shankara, yesterday evening to watch this kannada play Huttadalli Hutta ( Ant-hill within an Ant-hill ) written by TP Kailasam.

Why I was keen on watching the play ?....I was curious about the delivery of the dialogue by the artists. Are they going to use a wireless microphone, or few standing mikes ?

To my surprise, they do not use any. They speak little louder and hence probably I noticed that the hall was not a bigger one. It's just big enough to be audible for the last row audience. Theatre Plays are are quite a pull among the audience. Tickets were sold out and the house was full.

The plot of the play is simple. It is that of a couple who exploit the innocent through the several tricks they play.

I been little detached from kannada literature and havent read much in a long while. Wanted to pick up this "Samagra Sanna Kathegalu", but was in two minds...if am really so keen on it. Want to badly revive my taste for reading... but ..but but...

Mobile IP Protocol

To understand the function of Mobile IP, a great analogy to use is the Postal Service.

1. Postal mail is sent to you by placing a letter (the packet payload) in an envelope addressed to you (IP header).

2. The letter arrives at your local post office and is routed to you at your Home Address, as shown in Fig.

3. When you move, you tell the local post office (Home Agent) to forward packets to your new location (Care-of Address [CoA]). Now, when a letter addressed to your Home Address arrives at your local post office, it can now be readdressed (tunneled) to your new location (CoA).

4.The letter then arrives at the post office that services your new location (Foreign Agent [FA]) and is delivered to you at your new location (CoA), as shown in Fig. This mail delivery is done with no effort by the original sender of the letter.

FREE AIR

At Petrol pumps they have this FREE AIR facility.

Air pumps got this lengthy pipe to reach to the tyres. Since 2, 3 and 4 wheelers have different requirements for air pressures on front and back wheels,Air-filler person has to get up and go back and forth to adjust the pressures at the panel.

It’s painful when you have to do this job for thousands of vehicles every day.
I pity those air-filler person and handover a 1 Rupee coin every time they do this, though it’s FREE AIR.

Can’t we have a pressure-adjuster control at the tip of the pipe instead at the panel.

When we do such amazing this wirelessly, this should not be a tougher task.
Any mechanical engineers, please file a patent and fix this.

Sipping coffee at IIT-M Coffeeday

Sipping coffee at Coffeeday,IIT chennai campus deserves few lines.
Treating myself for a marathon day of 30 odd talks with a capuccino and two chocolate cookies is such a good feeling.

It will always remain in my wishlist of going back to school and study in a campus of this nature.
Cycling all around, Having great conversations over coffee, Listening to the talks of the accomplished, etc...in an atmosphere like this.
Will carry sweet memories of IIT chennai.

Forgot to mention this in my previous post....apart from seeking venture funding, what every other presenter had in common was, "We are looking for bright people" remarks.

Day 2 : Proto.in

Sat through 30 Presentations morning till evening. Just noted down the presentation names in my diary. Folks who presented today were not completely new faces. Have seen them at bar camp bangalore. Sloka, Seraja, picsquare, tazzaa to name a few.

What appealed to me, in no particular order, from the top of my head are these :

- Interface of spoteazy. Just two hops for a buying decision

- Features which are getting added to SeRaja and Taazza. I dislike the name Seraja though. It's such a turn off.

- Presenter of novatium and the approach of novatium for taking computing to the masses. Indian answer to 100$ laptop ?

- Efforts of Saloni to reach the rural mass with desicrew. Rural BPO.

- Unleash networks' network analyser ( protocol visualiser)

- TracBac's idea of collaborating visually

Catch more pics of the event here

First day in Chennai for proto.in

Landed here this morning at Chennai Railway station. Staying with my friend and college time project mate Mallikarjun Raddi.

Since the event is tomorrow, had no idea as to how to spend this day.
It was noon when I set out. Did nothing in particular, but aimless wandering.

Asked my friend, who had to go to office, if there's a MG road like place.
He pointed me to Mount Road.

It's not as pleasant a feeling as in MG Road. Spent some time at Higginbothams and wandering in Wallers road, equivalent of SP road of blore. Had two chapatis in lunch.

I doubt if the winter ever sets here. It's sweaty sweaty since morning and had to take a cold water bath!

It looks to me as a metro city which is aged.
Bright colors. Big Hoardings. Ugly buses.

Am heading to spencer plaza in the evening. Looks like a very popular forum-kinda shopping mall.

WiMAX now in Bangalore

I observed one funny line this morning in Hindu's Bangalore edition.Article is titled : WiMAX now in Bangalore

WiMAX is more efficient in preventing virus attacks.

The staff reporter probably has been told by the Aircel to do some PR work.The ill-educated reporter not taking any pain to do some research has printed this line.

If you read this line in isolation, it misleads to think of WiMax as an Anti-virus :)))

WiMax ( Worldwide Interoperability for Microwave Acess ) is an access technology. It works like an 'optical cable' in the wireless world with a much higher bandwidth.

Just another example of the opportunity which exists in Tech-Reporting.

That’s what is Science.

Any ball tossed up on earth’s surface returns with an acceleration of 9.6 m/sec2.
Throw it any number of times. I mean ANY.
It returns with the same acceleration.
That is consistency.
And it is measurable.

That’s what is Science all about. Consistently measurable with the same accuracy.

Anything which is immeasurable, or not yet understood is still a question to science.
It accepts challenges.

.....I was writing to a colleague on Science Vs God Debate.

Historica

This is what it read in Businessline's supplement this morning.
I quote two lines.

Every job on this planet is boring and monotonous, if you don't understand the science behind it.
So very true.

But let me take some time to talk about history than science.
Be it Iraq crisis, India's Satelite Program, New book of Richard Dawkins,Cricket team for the worldcup or New oil reserves in Bay of Bengal,What keeps me interested in a wide array of topics is the knowing of a bit of history in most of them, if not all.

Subject of History scared me in my High school. It required us to write page length answers in english. No one gave a feeling that History has a 'story' in it.

When I grew up I happened to read an Encyclopaeida of world history. It had all the colors and pictures. Where did civilisations start ? when did farming start ?Why did they Discover new lands ? Who colonised whom ? World wars.etc
View of the World, for me changed like never before. This is what I read in my Schooling days!!

Now, years later, the first thing I do before I delve into a new topic is trying to know its History and get a 'bigger picture', as they say. This is so very important to appreciate and make sense of the present.

Last Friday evening I spent sometime looking for Encyclopaedia of world history.I found few. But they are still far from my imagery of that encyclopaedia. Either they lack the depth and content or their presentation is not upto the mark.

I am looking for one : Encyclopaedia of world history.

Apple's iPhone a threat to mobile carriers ?!

Will Apple's iPhone be a threat to mobile carriers ?!
Because Verizon, Alltel and Sprint Nextel will miss out on the frenzy that is sure to be caused when Apple releases the device this June.

What might happen is hundreds of thousands buy the device almost immediately, and if those customers don't have Cingular, they *will* switch. Hence, the CDMA carriers will have to sit up and take notice.

Five things probably you do not know about me.

Five things probably you do not know about me.

1. I am born and raised in Shimoga and graduated in Electroncis from Bagalkot engineering college. My final year project was mostly done by project mates. I was just hanging around with them.

2. I hold a Post graduation degree from Bhagwan Jain Mahaveer college in Advertising and Public relations. I possess only the marks sheet and no degree certificate because I did not submit the project.

3. I attended 36 hour weekend Certificate course in Astrophysics, but did not get the certificate of completion because I did not submit the course project.

4. I discontinued French language course from Alliance Francaise in the midway because their teaching did not appeal me.

5. I signed up for environmental journalism distance course but did not submit their homeworks, because it was too boring.

Did you say...I am not a finisher ?
Well...In most of the cases, I had not my put heart in it, because I felt the process was so mechanical and mediocre.
There was no push to come out with original ideas.

But I have thoroughly enjoyed learning something new in each of them. I think that's what is more important than a nicely made certificate frame.

Free Web Hosting from Google

I have registered my .com domain site in anticipation of a free hosting from Google.

http://www.arvindtm.com

When it becomes available, you will start seeing my http://arvindtm.blogspot.com at http://www.arvindtm.com

Picture is worth...

Visual-Literacy.org is an online introductory tutorial about how data, abstract thoughts, and concepts can be graphically represented to more easily gain useful insights. One of their knowledge map examples is this excellent Periodic Table of Visualization Methods.
Rolling your mouse over each form of visualization brings up an example of the technique. It looks like it would very useful if you think a visualization is in order but you're not sure which specific kind to try.

Excellent. Now you know why most of the posts on this blog carry the picture.

Pattern in Climate

Why is that we see this pattern in climate.
Summer -> Rainy -> Winter season
Why not
Summer -> Winter -> Rainy season
Am curious why Rainy season follows summer.

Is it a global phenomena or just it’s specific to India ?
Does this pattern offer any particular advantage ?

Wikinomics- How Mass Collaboration Changes Everything

Increasingly, you should assume the best people reside outside your corporate walls

So very true.

The subtitle of the book is "How Mass Collaboration Changes Everything", and the authors do a great job covering all the latest tools and topics (e.g., wikis, Flickr, YouTube, etc.) As they see it, the four keys to success are openness, peering, sharing and acting globally.

Please gift me this book.

RFID expo India 2007

With the objective of supporting the Indian Industries to adopt the State of the Art technologies to survive in the international arena, Asia Technologies Limited is organizing a massive RFID event called RFID expo ‘Live’ India 2007

JANUARY 19,20,21 - 2007.
KTPO's INTERNATIONAL TRADE CENTRE,
WHITEFIELD, BANGALORE

Visit http://www.rfidexpo.in for more

Conference themes:
>> RFID for Manufacturing Excellence
>> RFID for Supply Chain Management & Logistics
>> RFID for Healthcare & Pharmaceuticals
>> RFID for Smart payment and Retail
>> RFID for India - A Business case analysis

Freedom Jam

I am in Bangalore for the last six years.
Most musically inclined bangalorean youth knows about it.I knew too.
About Freedom Jam. Free music festival.

Somehow, never got a chance to see the bands performing.
Finally it happened this Sunday.

For those who are new to this, let me do some intro.
It's a musical movement of muscians of all styles, performing on every 1st sunday of the month in places like
CKP ( Chitra Kala Parishat), Alliance Francaise, Yavanika.
Three hour show in the evening. Upcoming bands from schools,collegees and others come and play their original
compositions. Levi's is the sponsorer of the event.

In a nutshell, it's an open air pub without the beer.

There were 5-6 bands this sunday at CKP.
Of all, one worth mentioning band is AutoRickshaw. This was a featured band.
They had flown in from Canada, led by Subha Sankaran.



They presented a blend of western Jazz with an Indian classical touch with Tabla,
Percussion and Base guitar.

Every one else who performed,they had nothing but Rock music to offer.
Bit of a let down.
After a little while, that seemed like an overdose and I walked home.

One-sheeter Jam magazine has this classy Levi's Ad in the corner.


Victorian age woman's photo with a Copy reading:

"Back then,
women did not go to work.
Which is not to say
They did not work.

Women did not
File for divorces,
Which is not to say
They had happy marriages

They did not
have the pill,
or the vote.

And even the bloody levi's
belonged to the men

(Levi strauss and co. original for 150 years)

hats off to the copy writer.

On buying a Notebook

Saturday I was there at Koramangala ezone and Jayanagar with my friend Aju, who was buying his notebook.

What one should look for buying a notebook.
Here's list of things from top of my head

- Core Duo processor
( Intel or AMD, choice is yours. AMD powered ones are little cheaper.
64 bit processors are the new age processors.)

- RAM
( Minimum of 512 MB RAM, anything lesser can annoy you easily.

- DVD R/RW
DVD read writer is becoming the order of the day, before sony's blu-ray disc technology sweeps over.

- WindowsXP home edition. This is pre-loaded in the notebook. WindowsXP pro will be available in high end notebooks.
Got to see a WindowXP India starter edition, in low end notebooks.
Specially made for cost sensitive customers. Just hate that Poor man's version of windows.
It looked like pieces of bread thrown at street dogs.

- Other features to ask for include
802.11 a/b/g for wireless access
Bluetooth support
USB port
In-built speakers
Internal 56k modem

More or less all the laptop which are 40k+ do contain these features.
This is what we bought finally. Compaq v6000 for 46,000/-

I must share this. I also bought a notebook.The same day. 6-subject notebook from Mahavir publishers :) One notebook, which I cannot live without. I had a difficult time finding this particular note book for all these days. Finally hit it by accident at Jayanagar shopping complex. The last piece of this notebook in the shop. How lucky me.

The God Delusion by Richard Dawkins

I read the review of this book couple of days back.
The God Delusion by Richard Dawkins.

I faintly remember the exact words which appealed me in the review.
I did a look up on the net.
This is what sums up the theme of the book in Dawkin’s words.

“I am hostile to fundamentalist religion because it actively debauches the scientific enterprise.
It teaches us not to change our minds, and not to want to know exciting things that are available to be known.
It subverts science and saps the intellect”

debauch : Corrupt morally
subvert : Destroy completely

Surely my next buy.

There are two other titles, not so serious reading, by Scott adams.
God's Debris and The Religion War

Crossword Book Launch

Mohan Das:
A true story of a man, his people and an empire
by Rajmohan Gandhi

8th January 2007
Crossword
Residency Road
Bangalore

Making one FM Radio

Electronics for hobbying never caught up with me. Was lately thinking about it.
This morning I woke up with the thought of building an FM Radio.
Googled to find this interesting page of one-Transistor-FM radio.
I should find some time to work on it.

Are there any hands-on electronics engineers around ?

Proto.in

I am leaving to chennai on 19th to attend this event.
proto.in
It's an event to showcase new products, technologies and companies to a selected gathering.

Is any one joining from Bangalore ?

Communication Satelites are mirrors

Communication Satelites are nothing but mirrors at very high altitude.
You send out the signal from the earth station all the way to the satelites.( Uplink)
Satelites ( transponders) in turn pick up the weak signal which travelled long distances,boost them and retransmit back ( downlink) to many earth stations.

Tata Sky DTH provider has leased 12 ku-band transponders for its DTH operations on INSAT 4A.
Ku-band operates in 14 GHz uplink and 12 GHz downlink
INSAT 4A is a hybrid satelite which supports number of frequency bands. ( C-band, Ku-band, etc)

Power Control Vs Rate Control

Power Control Vs Rate Control in CDMA

EVDO is just not bothered about controlling and varying power ouput in the forward link. The output power is constant unlike in IS-95/1x.
IS-95/1x base stations vary the power and give more power to disadvantaged users who are in poor RF conditions.

If a user is in poor RF conditions, instead of varying the power output,EVDO base stations vary the data rate offered to the user. They reduce the data rate keeping the power constant.

New Year Movies

This is what I did on 30th,31st and 1st Nights


Gathering Storm




Michael Collins




World Trade Centre

CATV is not Cable TV

During my primary school days there were verfy few TV channels. Infact two.
National and Regional Language Channel.
There was one boom and People swtiched from Doordarshan to cable TVs.
People watched more channels 24Hours.

Early TVs received TV signals using Antenna on their terraces.
Reception used to be poor to receive regional langugage channels.
We used to increase the antenna height to improve the quality.

Inherently, these Yagi Antennas have limited capabilities. They cannot see much wider frequencies. This is the reason why we could not have access to those 24 hr variety channels.

What was the alternative ?

Let's move from housing a less powerful antenna at home to let some one in the community own a much better,wider and powerful antenna.
An antenna put on hill top with much better visibility to the satelite.

Since some one else owns a much better antenna, let's take away all those home-antennas.
We will let a cable from the community antenna run into our homes.
Arrival of the cable TV.

In most texts, they use CATV for Cable TVs. CATV actually stands for Community Antenna TV.