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Stratex Eclipse INU log in

2012-01-19T15:39:00.003+06:00

Once I have faced problem to login in stratex INU NCC card maint v.24 ethernet port. ODU was 300.

then somebody helped me over phone to configure the IP for connecting via eclipse portal 192.168.255.255 and then found the INU IP and then consider the class of IP and make pc IP as-

IP 169.254.1.1

sub- 255.255.0.0

then the connection is complete and I can finish up the INU configuration.

Comparism between Acer 4736z(dual core) and Acer 4740 (core i3)

2012-01-18T15:42:00.003+06:00

I have two laptops, one my own - the Acer Aspire 4736z and got another from office , that is Acer Travelmate 4740.

The Configurations are-

Acer Aspire 4736z-

Intel Pentium Dual core T4400(1M Cache, 2.20 GHz, 800 MHz FSB), 3GB DDR3 ram, 320GB Hard disc, 14inch Led backlight TFT Display, DVD writer, webcam, WiFi, Bluetooth. Buit in Graphics 32MB !

In my hand from May,2010

Another is Acer Travelmate 4740-

Intel Core I3( 350M processor, 2.27GHz, 3MB L3 Cache), 2GB DDR3 Ram, 250GB Hard disc, 14inch Led backlight TFT Display, DVD writer, webcam, WiFi, Bluetooth. Built in Graphics 64MB

In my hand from February, 2011

Both are running on Windows 7 Professional.

Performance:

Usually the 4740 is much expensive than 4736z- just because of the processor powered by intel new core series processor. Graphics is greater - only ram is 1GB less than 4736z.

On overall it has been expected to me to get higher performance from the Acer 4740.

But the scenario is on performance issue, the dual core one 4736z, is same with the core i3 one 4740.

I can play NFS most wanted, spider man, Max Payne etc. on both pc. I have no exceptional benefit from the core i3 one.

Sound Quality:

Sound quality is awful in 4740 ! it has a low volume from its built in speaker. Every time I need a external speaker connected to enjoy a movie, while the other notebook 4736z has a good volume quality from its built in speaker.

Webcam:

My 4736z gives me a cristal clear experience from its webcam but the new model 4740 gives a blackish and hezzy output from its webcam! not satisfactory.

Battery Backup:

Normally core series processor consume less power than previous processors. At the new state I got 4hr backup from 4740 notebook but afte 6 moth of use it gives me highest 2Hour. On the other hand the 4736z still give 2,8 hr backup eve its age now 1.6years !!

On in a conclusion, I am happy with my Acer 4736z while the expensive and newer version Travelmate 4740 is not so that high value of money.

Bangladeshi Bank Hotline Phone number

2012-01-11T17:10:00.003+06:00

Dutch Bangla Bank Limited (DBBL)

http://www.dutchbanglabank.com/

Hotline- 16216

Brac Bank Limited

http://www.bracbank.com/

Hotline- 16221

and +880 2 8852233

Standard Chartered Bank

http://www.standardchartered.com/bd/en/

Hotline-16233

+88 02 8957272

City Bank (American Express Card provider in BD)

https://www.thecitybank.com.bd/

Hotline- 16234

02 8813483, 8814375, 8813126

Eastern Bank Limited

http://www.ebl.com.bd/

Hotline - 16230

+88028332232

South East bank Ltd

https://www.southeastbank.com.bd/

Hotline- 16206

(88-02)9571115, 7160866, 9555466, 7173793

Bank Asia Ltd.

http://www.bankasia-bd.com/

Hotline- 16205

01730033988, 01730033999

* Note- 5 digit phone number can only be dialed from any Bangladesh land line or Cell phones

Teletalk Internet Packages & Settings

2011-11-11T23:46:00.003+06:00

Teletalk- a state owned mobile phone service provider in Bangladesh. They have started some campaign on GPRS / EDGE service lately where other have a wide range of service offers from past few years.

The offers have too many options for the subscribers to choose for right one which suite him/her-

1. Pay per use:-
To register "Pay per use" or "No Use No Pay" connection, write 'reg' and send SMS to 111.
Cost is 0.02/KB + VAT, for Ekush package- 0.0025tk/KB

2. 1GB/30 day Limited Pack:-
To register monthly limited "250tk per month-1GB" connection, write 'm01g' and send SMS to 111.
Purchase this pack by 250.00 + VAT

3. Daily 10MB Pack
To register daily limited "08tk per day - 10MB" connection, write 'd10m' and send SMS to 111.
Cost is 8tk

4. Weekly 50MB Pack:-
To register Weekly (7 days) limited "40tk per 7 days - 50MB" connection, write 'w50m' and send SMS to 111.

5. 100MB/15 day Pack:-
To register Fortnightly (15 days) limited "80tk per 15 days - 100MB" connection, write 'f100m' and send SMS to 111.

6.Daily Unlimited :-
To register daily unlimited connection, write 'dunl' and send SMS to 111. charge 50.00 + VAT/Day

7. Monthly Unlimited:-
To register unlimited GPRS connection, write 'unl' and send SMS to 111.
Cost is 666tk + vat for Shadheen 66 prepaid user & 800tk for all other package users.

Configuring your mobile handset:

Service Type	APN	IP	Port (optional)
No Use No Pay / Monthly Limited (1 GB) / Daily Limited (10 MB) / Weekly Limited (50MB) / Fortnightly Limited (100MB)	wap	192.168.145.101	9201
Monthly/Daily Unlimited	gprsunl	192.168.145.101	9201

MAC SUBLAYER

2011-07-13T11:14:00.001+06:00

To the wireless communications MAC-sub layer has many important procedures to do.
The lower level MAC layer functions describe the rules for sharing frequencies,
time slots, cells, and codes.
It has also influence on physical layer constructions, in which way it`s designed.
- share the radio spectrum
- voice communications
- channels for user traffics and also for the signalling purposes
The MAC-sub layer is quite important when we are designing the wireless systems.
The MAC-sub layer assign different MAC-functions to the logical channels.
Logical channels may be assigned to the same or different physical channels.
Logical channels will use an FDMA, TDMA or CDMA strategy for multiplexing.
The different logical channels for the MAC-sub layer may be divided into four types:
1. Synchronization and broadcast channels
2. Paging and access channels
3. Control channels
4. Traffic Channels

Useful parameters for Fiber Link budget

2011-05-20T23:48:00.005+06:00

Some useful parameters for calculating fiber link budget. This is for simple networks only. To view this in pictures Please click on the images.

Picture-1

Picture-2

1.Fiber loss at the operating wavelength

Cable Length	2.0	2.0
Fiber Type	Multimode		Singlemode
Wavelength (nm)	850	1300	1310	1550
Fiber Atten. dB/km	3 [3.5]	1 [1.5]	0.4 [1/0.5]	0.3 [1/0.5]
Total Fiber Loss	6.0 [7.0]	2.0 [3.0]

-Brackets for maximum value.

2.Connector Loss
Multimode connectors losses of 0.2-0.5 dB. Singlemode connectors losses of 0.1-0.2 dB. Max allowable 0.75

3.Splice Loss
0.1-0.5 dB for multimode splices, 0.3 for singlemode fiber less than 0.05 dB

those are the basic for fiber link budget, for more accuracy there also need to take account of-
Add the fiber loss, connector and splice losses to get the link loss. Data From Manufacturer's Specification and
Loss Margin Calculation

Dynamic Range (dB) (above)	15	15
Cable plant Link Loss (dB)	3.8 (Typ)	7.05 (TIA)
Link Loss Margin (dB)	11.2	7.95

Airtel Dolbol

2011-04-19T20:44:00.005+06:00

New Package from Airtel bangladesh operation.
Here is the detail which is not mentioned on airtel website

Pulse=30 Sec
Community (FnF)=Unlimited

airtel 2 airtel (Within Community)=0.29Tk.
airtel 2 airtel =0.59Tk.
airtel 2 Other=1.19Tk.
SMS to BD mobile=0.49Tk.
International SMS=2.49Tk.

To Join , Write
d
and SEND to 7353 (FREE)

For Community Code : http://www.bd.airtel.com/Files/University_and_College_Codes.pdf

For Details Dial 1212 (FREE)
Or Kindly Visit : http://www.bd.airtel.com/commonpage.php?cat_id=78

To Join Any Community Like "DU/CU/KU/BUET/AUST/AIUB" Just Write

join du/cu/ku/buet/aust/aiub (Community Code)
and SEND to 7353 (FREE)

After Migrating To "airtel Dolbol" & Joining To Any Community , All Of Ur Community People Can Talk To Each Other @ 0.29Tk./ Min , 24Hrs , 30 Sec Pulse , Anywhere From Bangladesh !!!

see more-

Citycell Introduces 3 new prepaid packages

SDH MUX - Network Level Protection

2011-03-05T01:37:00.005+06:00

:::SDH MUX - Network Level Protection:::
The network level protection includes MSP protection, SNCP protection and DNI protection.-

1. Linear MSP
-- The linear MSP supported by the equipment are 1+1 single ended switching, 1+1 dual ended switching and 1:N dual ended switching MSP.

2. MSP Ring
-- The MSP rings supported by the equipment are four fiber MSP ring and two fiber MSP ring.

3. SNCP
-- The subnet connection protection schemes are SNCP, SNCMP and SNCTP.

4. DNI
-- The DNI network topology protection scheme effectively enhances the reliability of inter ring services. The DNI realizes the protection of services between two rings, which are networked
by the equipment from different vendors and adopt different protection schemes. The DNI provides protection in the case of fiber failure and node failure.

5. Fiber Shared Virtual Trail Protection
-- When the fiber shared virtual trail protection is used, an STM 64, STM 16, STM 4 or even STM 1 optical channel is logically divided into several lower order or higher order channels.
These channels are then connected to other links at the channel layer to form rings. In the case of the rings at the channel layer, protection schemes such as the MSP, SNCP and
non protection can be set accordingly.

6. Optical Path Shared MSP
-- In the optical path shared MSP scheme, an optical interface can be configured into multiple MSP groups, so multiple MSP rings can share the same fiber and optical interface.

7. RPR Protection
-- The RPR protection schemes are Wrapping and Steering.

8. VP Ring/VC Ring Protection
-- The protection scheme at the ATM layer is VP Ring/VC Ring.
-------------------------------------------------------------------
thats it, I will share more next, but before that I have to study more .
Thanks

BTCL -The only Govt. PSTN operator in Bangladesh

2010-12-27T15:03:00.005+06:00

BTCL - The Govt owned only landphone PSTN operator in Bangladesh. Its also largest and oldest operator in Bangladesh PSTN history. Its named BTCL from 1st of July, 2008. Before that it was named BTTB, most popularly knows as T&T. After becoming BTCL it was converted to public Limited company to provide good response and service to the Bangladesh people who r the customer for the state owned company. People can get his BTCL connection more easily and more cheap connection fees. Not only that its call rate is much cheaper than before when it was BTTB.

To get a new connection it costs as follows-
1. Dhaka Multi-Exchange+ Narayanganj proper + Gazipur proper- 2000/= Tk
2. Chittagong Multi-Exchange- 1000/= Tk
3. Rest of the Districts, Zilla, Upazilla and Growth Centres- 600/= Tk

From from 01 July 2009 BTCL call rates as follows-
i)BTCL to BTCL (Local/ Nationwide)--- 0.30Tk/min
ii)BTCL to other in-country operator phn/ mobile phn- 0.65tk/min

BTCL not only provide voice call service , they have also too many service feature.
It has data service , Dial up internet service, connectivity solution service, ADSL broadband service, internet bandwidth service, .bd domain service- web hosting and much more. See the figure -

To made BTCL dial up connection existing client need only to dial
Premium dialup: 0101234 (Multimetering) - internet using rate is 0.30tk/min. No need to hassle with registration through BTCL office.
BTCL ADSL is fastest and reliable internet solution for the customer stay near BTCL exchanges. It has different packages starting from 300tk/month. For detail visit- http://www.bcube.net.bd/

Though BTCL has many more services but its service quality is not good through some of its old model rules and regulations. It problem ticket solving processing time is much higher than other private phone operators.

My previous post on this BTCL was it. Hope this data on BTCL will be helpful for others, if so please dont forget to make a comment.

SDH Overhead

2010-12-14T13:00:00.005+06:00

SDH Overhead
The SDH standard was developed using a client/server layer approach. The overhead and transport functions are divided into
layers. They are:
*-Regenerator Section
*-Multiplex Section
*-Path

The layers have a hierarchical relationship, with each layer building on the services provided by all the lower layers.
This section details the different SDH overhea
information, specifically:
*-Regenerator Section Overhead
*-Multiplex Overhead
*-Path Overhead

Regenerator Section Overhead
The Regenerator Section Overhead contains only the information required for the elements located at both ends of a section. This might
be two regenerators, a piece of line terminating equipment and a regenerator, or two pieces of line terminating equipment.
The Regenerator Section Overhead is found in the first three rows of Columns 1 through 9 of the STM-1 frame. Byte by byte.

Multiplex Section Overhead
The Multiplex Section Overhead contains the information required between the multiplex section termination equipment at each end of the
Multiplex section (that is, between consecutive network elements excluding the regenerators).
The Multiplex Section Overhead is found in Rows 5 to 9 of Columns 1
through 9 of the STM-1 frame . Byte by byte.

Higher-Order Path Overhead
(VC-4/VC-3)
The Path Overhead is assigned to, and transported with the Virtual Container from the time
it’s created by path terminating equipment until the payload is demultiplexed at the termination
point in a piece of path terminating equipment.The Path Overhead is found in Rows 1 to 9
of the first column of the VC-4 or VC-3 . Byte by byte.

(Click the images for large display.)

Attenuation

2010-11-21T13:32:00.001+06:00

Attenuation is the process of reducing an RF signal’s amplitude. This is occasionally done intentionally with attenuators to reduce a signal’s strength to fall within a regulatory domain’s imposed constraints. Loss is the result of attenuation, and gain is the result of amplification. RF cables, connectors, and devices may have some level of imposed attenuation, and this attenuation is usually stated in decibels and is often stated as loss in decibels per foot—this is also known as insertion loss. Insertion loss is the loss incurred by simply inserting the object (cable, connector, etc.) into the path of the RF signal between the source and the intentional radiator.

( sometimes small topics are not easy to remember, I felt in this problem several times. so I am try to help myself.)

SDH Rates

2010-11-21T12:24:00.002+06:00

>>SDH is a transport hierarchy based on multiples of 155.52 Mbit/s

>>The basic unit of SDH is STM-1:
STM-1 = 155.52 Mbit/s
STM-4 = 622.08 Mbit/s
STM-16 = 2588.32 Mbit/s
STM-64 = 9953.28 Mbit/s

>>Each rate is an exact multiple of the lower rate therefore
the hierarchy is synchronous.

SDH - Synchronous Digital Hierarchy

2010-08-07T01:00:00.002+06:00

SDH (Synchronous Digital Hierarchy) is a standard for telecommunica-
tions transport formulated by the International Telecommunication Union
(ITU), previously called the International Telegraph and Telephone
Consultative Committee (CCITT).
SDH was first introduced into the telecommunications network in 1992
and has been deployed at rapid rates since then. It’s deployed at all
levels of the network infrastructure, including the access network and
the long-distance trunk network. It’s based on overlaying a synchronous
multiplexed signal onto a light stream transmitted over fibre-optic cable.
SDH is also defined for use on radio relay links, satellite links, and at
electrical interfaces between equipment.
The comprehensive SDH standard is expected to provide the transport
infrastructure for worldwide telecommunications for at least the next two
or three decades.
The increased configuration flexibility and bandwidth availability of SDH
provides significant advantages over the older telecommunications sys-
tem. These advantages include:
A reduction in the amount of equipment and an increase in network reliability.
The provision of overhead and payload bytes – the overhead bytes permitting
management of the payload bytes on an individual basis and facilitating cen-
tralised fault sectionalisation.
The definition of a synchronous multiplexing format for carrying lower-level
digital signals (such as 2 Mbit/s, 34 Mbit/s, 140 Mbit/s) which greatly simpli-
fies the interface to digital switches, digital cross-connects, and add-drop
multiplexers.
The availability of a set of generic standards, which enable multi-vendor
interoperability.
The definition of a flexible architecture capable of accommodating future
applications, with a variety of transmission rates.

In brief, SDH defines synchronous transport modules (STMs) for the
fibre-optic based transmission hierarchy.

Technology that Used for FTTH

2010-08-07T00:44:00.002+06:00

MPLS:

With Multi Protocol Label Switching (MPLS) technology, support can be provided nationwide for all layer 2 and layer 3 encapsulations.

MPLSMPLS is the latest technology to be deployed in data communication. It leverages existing ATM hardware. It is fast forwarding. It can be used both for IP traffic enjoying, VPN and other IP based services like voice/video.

MPLS is supported by IETF (International Engineering Task Force).

GPON (Gigabit Passive Optical Network):

GPON is high bandwidth shared fiber access technology that is used around the world for Fiber to the Home (FTTH) applications. GPON technology is also deployed for FTTx. With GPON, home users can enjoy converged triple play (data, voice & video) services at home with quality and speed. GPON uses ITU-T standard G.984. With ITU standardization on GPON, multiple vendors around the world are manufacturing equipment for GPON and operators are offering services through GPON. With a single Core Fiber G.984 allows for 60 km maximum reach and 20 km of differential reach with up to 128 subscribers at the moment.

SDH
SDH (Synchronous Digital Hierarchy) is an international standard for high speed telecommunication transmission system over optical/electrical networks which can transport digital signals in variable capacities.

It is a synchronous system which intends to provide a more flexible, yet simple network infrastructure. SDH deployed for long haul network. Capacities of SHD range from STM-1, STM-4, STM-16 to STM-64 (STM1 = 63 E1).

DWDM:
(Dense Wave Division Multiplexing) DWDM is an optical technology to increase the bandwidth over existing fiber optic backbone.

A key advantage of DWDM is that it is a protocol and bit-rate independent. DWDM based networks can transmit data in IP, ATM, SDH and Ethernet.

DWDM can handle bit rates from as low 100 Mbps to several gigabits over a single strand of fiber. DWDM achieves this by using various wavelength of light in the same fiber.

Renewable Energy Technologies Suitable for Bangladesh

2010-01-11T00:08:00.002+06:00

Different types of renewable energy technologies (RET) applications suitable for Bangladesh are described in the subsequent headings.

● Solar Thermal
● Solar photovoltaic (SPV)
● Biomass
● Small Hydro
● Waste Energy

)()()()()()()()()()()()()()()()())()()()()())))(()()()(((())()()()())()()()))()()(()(())(((()))((((())))(((()))

Solar Thermal Energy:---------
Solar thermal energy is gathered by the use of parabolic mirrors. The mirrors are positioned to face the Sun, and a clear tube is placed at the focal point where a liquid flowing through the tube is heated. Next, the pipes are run through a boiler where the steam generated spins the generators creating electricity.

---
Biomass:------------------
Biomass refers to living and recently dead biological material that can be used as fuel or for industrial production. Most commonly, biomass refers to plant matter grown to generate electricity or produce bio fuel, but it also includes plant or animal matter used for production of fibers, chemicals or heat. Biomass may also include biodegradable wastes that can be burnt as fuel. It excludes organic material, which has been transformed by geological processes into substances such as coal or petroleum.
Industrial biomass can be grown from numerous types of plants, including miscanthus, switchgrass, hemp, corn, poplar, willow, sorghum, sugarcane and a variety of tree species, ranging from eucalyptus to oil palm (palm oil). The particular plant used is usually not very important to the end products, but it does affect the processing of the raw material. Production of biomass is a growing industry as interest in sustainable fuel sources is growing

Wind Energy: ---------------
The origin of wind is complex. The dry land heats up (and cools down) more quickly than the seas do. The differential heating drives a global atmospheric convection system reaching from the Earth's surface to the stratosphere, which acts as a virtual ceiling. Most of the energy stored in these wind movements can be found at high altitudes where continuous wind speeds of over 160 km/h (100 mph) occur. Eventually, the wind energy is converted through friction into diffuse heat throughout the Earth's surface and the atmosphere. There is an estimated 72 TW of wind energy on the Earth that potentially can be commercially viable

__________-----------------____________________

Thats all for now. later try to write more.

Goodluck

enable POP3 in YAHOO

2010-01-09T23:05:00.005+06:00

thin u can use ur yahoo mail in ur own PC- in outlook or t=in Thunderbird or in any other mail client software. that will be an amazing experience to use,

here the tips, mainpost writen by amit097, from samu blog.
http://www.somewhereinblog.net/blog/amit007/28988884- this the link.
______________________________________________________________

আমরা যখন মেইল সেট আপ করি ইয়াহুতে তখন POP3 অপশানটি থাকে না। এই অপশান পেতে হলে পয়সা দিয়ে Yahoo !Plus কিনতে হয়। কিন্তু মেইল সেটআপে একটু পরিবর্তন করে এই অপশান আপনি এনাবল করতে পারেন এবং সকল মেইল আপনার পিসিতে (আউটলুক/লাইভ মেইল) নিয়ে আসতে পারেন।
১। মেইলে লগইন করুন। উপরে ডানদিকে Welcome, . সেখানে আপনার নামের উপর ক্লিক করুন।Account Information চলে যাবেন।
২। Account Information থেকে Preferred Content সিলেক্ট করুন Yahoo Asia
৩।ক্লিক করুন Finish এবং Accept the Terms।
৪।আবার ক্লিক করুন Finish।
৫।এখন আবার লগ ইন করুন।Yahoo Asia লোগো দেখতে পাবেন।
৬।ডানদিকের উপরে অপশন সিলেক্ট করুন
৭। আপনার এখন POP3 Access and Forwarding অপশন থাকবে Management এর নিচে।

মেইল সেটআপের জন্য
1.Open Microsoft Outlook
2.Go to Tool>Account Settings
3.Under Email Tab Press New.
4.Click The Check Box Manually configure server settings and Press next
5. Select Internet-Email and press next.
6.Fill UP User Information.
Server information
Account Type > POP3
Incoming Mail Server : pop.mail.yahoo.com
Outgoing Mail Server(SMTP): smtp.mail.yahoo.com
Fill up login Information
Click More settings:
Outgoing server tab select the first check box.
Advance tab select The first check box (SSL)
Leave a copy of messages on the server.এটাও চেক করুন । না করলে আপনার সব মেসেজ yahoo থেকে মুছে যাবে । তাই খুব খেয়াল কৈরা।
Ok দিন।
আপনার Yahoo সার্ভারের সব মেইল এখন আউটলুকে জমা হবে।
_____________________________________________________
for detail to active ur pop3 u can see this ink also.
http://www.somewhereinblog.net/blog/vadaimya_pola/29009992
i am succeded. u may not get same as content in ur yahoo page. use ur common sense to find out them,

actually this post is essential to me. so that i put it in my site. i have no authentication from the original writer.
i think he will not mind.

I Love my Bangladesh

2009-12-16T13:24:00.002+07:00

Today is 16 December. The victory day of my country. the country where i grew up. The country I love most.

Bangladesh got it independence after a long time of 9month of war with loose of bloods of country people in 1971.

today is 38 years of independence victory celebration day.

Happy to say I am Bangladeshi and live in Bangladesh.

BJT(Bipolar Junction Transistor )

2009-09-23T01:29:00.004+07:00

BJT has three modes or regions of operation that is
1. Active
2. Cut off
3. Saturation

2.1.1. Active Mode
If the base-emitter junction is forward biased and the base-collector junction is reverse biased, the
transistor is active in the "linear region." There is controllable current flow through the transistor, with the collector and emitter currents being controlled by the base current.

Equations for Active Mode-
In active mode, we have:
(1) VBE ≈ 0.7 V
(2) IC = β IB; where β is a parameter of the particular BJT and is called the common-emitter current gain.

Two types of active mood, that’s are :-
2.1.1.1. Forward Active

In forward active mode, that is the base-emitter junction diode is forward biased (Vbe=0.7V), and the base-collector diode is in cut-off mode (Vbc<0.6V). The current through the base terminal is directly proportional to the collector current;
Ic=*Ib, (- common-emitter current gain.).
The emitter current is the sum of the two other terminal currents; Ie=Ib+Ic.
Slightly modifying the circuit voltage and/or resistor characteristics can drive the BJT into saturation.[7]

2.1.1.2. Reverse Active
In reverse active mode that is the base-collector junction diode is forward biased (Vbc=0.7V), and the base-
emitter diode is in cut-off mode (Vbe<0.6V). The current through the base terminal is directly proportional to the emitter current;
Ie=R*Ib.
The collector current is the sum of the two other terminal currents; Ic=Ib+Ie.
2.1.2. Cut-Off
BJT is in cut-off mode, meaning there is an insignificant amount of current flowing through its three terminals. In order for the transistor to begin operating in forward active (linear) mode, the base-emitter voltage must be at least 0.6V (approx.), also known as the edge of conduction point.
When the base emitter voltage is below the edge of conduction point, the BJT could operate in reverse active mode, if the base collector voltage is larger than cut off voltage (i.e. VDD<-0.6V) [7].
2.1.2.1 Edge of Conduction
The BJT is at the edge of conduction, that is a slight rise in the input voltage will drive the BJT in to forward active (linear) mode.
The current at the terminals at this point is still insignificant, in the microamperes range (and lower)
2.1.3. Saturation.
When both PN junctions are forward biased, the transistor appears as a short circuit. The collector current is maximum and is controlled by external components, not the base current. VCE, the voltage between the collector and emitter will be about 0.1V (near zero).[4]
The BJT is operating in saturation mode, meaning both base-collector and base-emitter p-n junctions are forward biased resulting in
Vbe=0.8V and Vce=0.1V (approx.).
The collector current cannot keep up with the base current, thus the linear base-collector relationship is lost, and
Ic < *Ib.
The emitter current is still equal to the sum of the base and collector currents. Ic is at a maximum for the specific circuit resistors and voltage sources, and is constant when the BJT is saturated.
Slightly modifying the circuit voltage and/or resistor characteristics can drive the BJT into forward active mode [6].

(frm my thesis 1-2)

BJT operation Modes

2009-07-09T03:41:00.002+07:00

Operational Modes/ Regions:
EBJ CBJ Mode
Forward Reverse Forward active
Forward Forward Saturation
Reverse Reverse Cut off
Reverse Forward Reverse active
Depend on biasing we can get different type of output from the BJT. We knew that BJT has two junctions that’s are Emitter-Base junction (EBJ) and Collector-Base junction (CBJ). By giving different input among these two junctions, we get those moods:--
For the case of digital circuit we use the biasing of Forward-Forward or Reverse-Reverse between EBJ-CBJ. And in the case of analog circuit we make biased between EBJ-CBJ is Forward-Reverse or Forward-Reverse. But the most common using for amplifying is Forward active mode. [2]
So it can be tell that there are three modes or regions of operation that is
1. Active
2. Cut off
3. Saturation

Abstract of my 1st thesis in 2005

2009-07-09T03:13:00.001+07:00

Bipolar Junction Transistor (BJT) has an important role in Electronics. It was an epoch making invention for amplifying action on 23 December, 1947 by three scientists from Bell Telephone Laboratories. It is smaller and lightweight, needless of giving or exempted heat, more efficient and lower operating voltage needed. It has too many uses around the world for different types of switching and amplifying. This is an important matter to have an idea on its (BJT) structure and operation to use it in different modes of using as we want to use it as our desire mode. Because the working output of a BJT depends on its structure and on its operation. In this term paper we have focused on BJT structure and its operation.

Bangladesh tour of west Indies-2009

2009-07-04T08:43:00.004+07:00

Cricket:-
Bangladesh

vs West Indies Fixtures:::

(time in Bangladeshi Standard --considering DST+1)

Timing	Teams	Venue
Fri 3 July - Sun 5 July 21.00 PM	Tour Game – Bangladesh v TBC	Barbados
Thu 9 July - Mon 13 July 21.00 PM	1^st Test – Bangladesh v West Indies	Arnos Vale Ground, Kingstown, St Vincent
Fri 17 July - Tue 21 July 19:30 PM	2^nd Test – Bangladesh v West Indies	National Cricket Stadium, St George's, Grenada
Fri 24 July 20.30 PM	Tour Game – Bangladesh v TBC	Dominica
Sun 26 July 20.30 PM	1^st ODI – Bangladesh v West Indies	Windsor Park, Roseau, Dominica
Tue 28 July 20.30 PM	2^nd ODI – Bangladesh v West Indies	Windsor Park, Roseau, Dominica
Fri 31 July 20.30 PM	3^rd ODI – Bangladesh v West Indies	Warner Park, Basseterre, St Kitts
Sun 3 Aug 01.00 PM	Only T20I – Bangladesh v West Indies	Warner Park, Basseterre, St Kitts

Now at Abroad....

2009-04-11T23:54:00.003+06:00

When the times going to feel myself that i had lost all my time to spare then i have a phone call to come UAE. i accept and be hurry to atttend the order which came by the phone call...
It was a dramma , i think. I was in a bus to rangamati to visit my father. accompanied with my mother and sister. when my bus was at Jattrabari , my cousin phone me to say that, i have to go UAE. If possible i should return that time. but the was not in fevour of me. it was night, and no good transport for me to back me to my home with my family. i reached at rangamati, stayed there full day and back in dhaka in that following night.

After taking essential steps in just 2 days, i was ready to bye my house for one last time.

It was spring when I last see at the sky before entrance in the Airport 'ZIA". time was midnight 2 am.. I am afraid to face the formalities of Immogration, coz every body know the harrasment of BD officials. But with help of someone i cross the barrier easily. My flight took off at 5- 40 am.
it was not amazing experience , coz nothing was too heavy feeling. it was smooth to take off of ETIHAD airways............

I landed at 8-35 am local time at UAE. that mean in that time in BD time was 10-35. it was good journey to see air hostages are moving arround to us....;)

After landing, i amazed to see the airport, is it Airport or a shopping Mall? i took time to realize myself that i am in airport and i have to pass immigration. then i ask someone to indicate the immigration. after retina scan i cross the immigration and took my laggege and come out from the Airport, where my cousin is waiting for me. they pick me up and took me to their home, which is 200 Km far from the Abudhabi Airport. but we crossed 200 Km in just 1.4o Hr, coz we can drive at 140 KPH !!! it cant be think in BD......

I am in amazed scense.............................

dont know how long the sense will continue...

Miscellaneous on Transformer

2009-02-22T02:12:00.001+06:00

Miscellaneous on Transformer

* 3-Фtransformer’s each phase should have balanced load. Otherwise insulation will break by overheat and Tx will be damaged. In Bangladesh 80 % cases Tx are being damaged due to unbalance load.

* If core is cut by Miter shape that increases efficiency. This core helps full of flux cuts, so that its efficiency is higher.

* HT side keeps in outside of the winding cause most cases HT side winding need to repair.

* In REB (Rural Electrification Board) use 1-phase Tx, that can be identified by 1- bushing in HT side, that has 6350 volts. Cause in rural areas maximum loads are 1-phase. That case neutral is comes from earthling of a side of Tx.

* Distribution Transformers consumer side end (LT) is made Y connection so the neutral can be used. HT side connection is ∆.

* For minimizing of EDDY current loss cores are made of peace of sheets.

read more
Inside Construction.
Outside construction

Synchronus Generator Demarties

2009-01-17T03:34:00.001+06:00

A Synchronus generator's ability to produce electric power is primarily limited by heating within the machine. When the generator's winding overheat, then the life of the machine can be severaly shortened.

Transformers Inside Construction

2008-11-15T02:22:00.000+06:00

Inside Construction:-

Transformers (Tx) can be classified by 2 types by internal structure-

Core type-
This can be easily made and can be repair easily. But it has 1-3% system loss. This is made of high permeability silicon steel.

Shell type-
Highly efficient, has less than 1% system loss. Difficult to repair damage.

Coils-
For a step down Tx HT coil has more turn but thin coils, cause of this HT side has high voltage but small ampere of current. LT is vice versa. But the power will be same at both HT and LT side.

Lamination
Lamination makes separate one layer from its neighbor layer. Insulation is given by a thin non-conducting layer. Between core and LT coil one layer of Lamination and between LT & HT one layer of Lamination used. No electrical connection cant established between two.

3-Ф Transformer construction- Outside

2008-11-14T03:53:00.003+06:00

Outside Construction:-

Nameplate Ratings:-

Normally nameplate rating indicates some necessary information of the Tx like manufacturer name, HT-LT ratio, voltage ratings; tap changing ratings, weights, vector group, frequency, serial no. etc.

Bushing-
A bushing is a component that insulates a high voltage conductor passing through a metal enclosure. In Tx bushing used for both High Voltage (HV) and low voltage (LV) side. HV side bushing is called HV Bushing and LV side bushing is called LV Bushing. HV bushing is greater size than LV Bushing. Normally in distribution Tx HT side has 3 bushing and at the LT side there are 4 bushing.

Radiator-
Radiator is used for cooling the Tx. Transformers can be hotter by any cause, like over load, over current, unbalanced load, temperature etc. Radiator helps to keep cool the Tx and keep safe from damage.

Lightning Arrestor-
Lightning arrestor is used to protect the Tx from lightning. If lightning occur in the line, this very high voltage surge can bypass through this arrestor and normal voltage pass through the line. Two pin with a small distance is used for this purpose.

Tap changer-
A tap changer is a device used in transformers for regulation of the voltage to required levels. This is normally achieved by changing the ratios of the transformers on the system by altering the number of turns in one winding of the appropriate transformer. This tap changer used in HV side. There are 5 taps to maintain the voltage between certain limits. Each taps has certain percents of impacts on LT side. Tap change is done in off condition.
Conservator Tank-
Conservator tank is an oil tank above the transformer filled with Tx oil. The oil helps cool the transformer & it also provides part of the electrical insulation between internal live parts. Tx oil has certain dielectric constant. This tank have also oil level indicator. In some cases there is safety valve instead of a conservator tank just to release the gas if the oil gets too hot for any kind of short circuit fault. Conservator tank is not fully filled up with oil and some part of it is left empty.

Buchholz relay-
Buchholz relay stay In the middle of the connecting pipe of conservator tank and the Tx. It monitors the oil level, gas forming etc. This is slow in operation.

Breather-
Conservator tank is not fully filled up with oil and some part of it is left empty. When the oil expands because of heat then the empty part is filled with oil. The oil becomes cooler when Transformer is not at full load. Then the breather made of silica gel sucks in moister less air from outside to fill up the empty space inside the tank. So, within the breather air can come through it to maintain pressure inside the tank. But it protects moisture to come in conservator tank. Moisture can reduce the dielectric constant of the oil. In normal condition silica gel is blue coloured. But when it becomes white color that means it needs to be changed.

Transformer Types

2008-11-14T03:45:00.001+06:00

As the power system has major 3 parts, Transformers are also can be divided into 3 parts-

Transformer- used in Generation side.
Transformer- used for distribution
Instrumental Transformer- used for metering or protection relaying.

Distribution Transformers are used normally 100KV to 500KV. For consumer end distribution, bellow 250KV Tx is used because if there is any damage, that will make small portion out of order.

BTCL call rate

2008-11-13T04:35:00.004+06:00

BTCL- govt owned land phone company has reduced its call rate in amazing rates,
so check it now.

www.btcl.gov.bd

in this rate, u can take ur connection as low as 600 tk!!

can call local calls as low as 10 paisa per minute.

Can use internet at 10 paisa per min.

Etc too many benefits are there to make u scream to by this and use this phone,

how to connet internet via BTCL phone-------------------------

You can enter into the internet through BTCL Premium Dial-up facility using BTCL Pre-paid Calling Card. Firstly
you have to have a BTCL fixed telephone connection and a dial-up modem installed in your Computer or Laptop.
• Then you need to create a dial-up window and put User Name: bttb, Password: bttb, Access code (010201),
Card no., PIN no., etc separated with same number of commas (,,,) as shown in the following figure.
• Premium dial-up tariff is same as BTCL Local call tariff (now 15 paisa/minute at Peak-time and 10 paisa/minute
at Off-peak time). Off-peak duration is from 20:00 BST to 8:00 BST daily and this is for 24 hours at Weekly &
Govt. Holidays. VAT will be added to this charge.
• With a 200Tk. BTCL Pre-paid Calling Card you can use Premium Dial-up internet upto 1,111 minutes (18 hours
& 30 min.) during Peak time and 1,666 minutes (27 hours & 45 min.) during Off-peak time.
• And with a 500Tk. BTCL Pre-paid Calling Card you can use Premium Dial-up internet upto 2,777 minutes (46
hours & 16 min.) during Peak time and 4,166 minutes (69 hours & 25 min.) during Off-peak time.

so

carry on....

Tatum

2008-11-05T20:21:00.002+06:00

This is our Tatum sona

ICT developement in Bangladesh

2008-11-05T03:49:00.001+06:00

ICT & Young people
Information is an aid that helps a person to gain knowledge, make decision easily and increase awareness. Communication is a system to know that information easily. Technology is magic which can turn a person faster, smart and more efficient. Because technology helps to gather information as well as ease of communication. The world is tied with these words called Information and Communication Technology (ICT).
Young generation is always a big asset for the country, because they are energetic, innovative, eager to learn, keen to know more and a good potential to building the countries future. They need to stimulate properly.

Devolvement by Young people inspired from ICT
By using ICT developed countries are going to be more developed. But in the third world country, they are not very handy on ICT. A broad percentage of young people in those countries are out of job as they have no scope for job. So for this country ICT and young peoples are can be a very good unit for nation’s advancement. As young peoples are very good learner so if they get chance to learn ICT they should do well and they can help to develop ICT sector by helping others to use ICT, by their using innovative brain and by use their energy.

From Bangladesh Perspective
In the country like Bangladesh young people who are good at ICT can take very good steps to remove digital divide. As we know in Bangladesh many people lie between poverty line and has a small percentage of educated people. Learned young people can help those people by teaching to know what is ICT and its benefits. Young people can also help them by giving chance to use new technologies which they did not use before. By using, those poor people can find new era of his developed life. Not only for Poor’s, a learned person can teach another person. Thus the whole population can know about the ICT.
The main cause of digital deviance is the cost of using ICT, from the perspective of Bangladesh. If the young students can use different technologies of ICT in his institution, he can help his family to take flavor of ICT.
As in Bangladesh, labor cost is very cheap comparative to developed country, so the young people can concentrate on outsourcing work for those developed country which can be very good impact on our countries economical situation. That will also reduce the unemployment percentage.
Not only this, young people can use his brain to innovation of new, cheaper and simple technology for general people.
Using ICT, young people can be joined together and united from different place from the country and can made revolution by rising peoples opinion.

Conclusion
As said before, Young people need to stimulate properly. This stimulation can come from the elders and from the patriotism. The Government needs to help with proper guidance and infrastructure. Developed countries have to come forward to help. Thus leading by young people ICT can be developed and digital divide should be reduced

Standard features and Pin diagram of AT89C51

2008-11-05T02:35:00.000+06:00

· 4K bytes of Flash

· 128 bytes of RAM

· 32 I/O lines (P1, P2, P3, P4)

· Watchdog timer

· two data pointers

· two 16-bit timer/counters

· a five-vector two-level interrupt architecture

· a full duplex serial port

· on-chip oscillator and

· Clock circuitry.

89C51 Microcontroller

2008-11-05T02:28:00.000+06:00

89C51 Microcontroller

A microcontroller (MCU) is a computer-on-a-chip, containing a processor, memory, and Input-output functions. It is a microprocessor emphasizing high integration, in contrast to a general purpose microprocessor. In addition to the usual arithmetic and logic elements of a general purpose microprocessor, the microcontroller integrates additional elements such as read-write memory for data storage, read-only memory for program storage, EEPROM for permanent data storage, peripheral devices, and input/output interfaces. At clock speeds of as little as a few MHz or even lower, microcontrollers often operate at very low speed compared to modern day microprocessors, but this is adequate for typical applications. They consume relatively little power (mill watts), and will generally have the ability to sleep while waiting for an interesting peripheral event such as a button press to wake them up again to do something. Power consumption while sleeping may be just nano watts, making them ideal for low power and long lasting battery applications. The AT89C51 microcontroller is a low power hi performance CMOS microcomputer (8 bit). It has 4k bytes of downloadable and erasable read only memory and 128 bytes of ram. The device is manufactured using Atmel’s high-density nonvolatile memory technology and is compatible with the industry-standard 80C51 instruction set and pin-out.

Microcontroller--some basic classification

2008-11-05T02:02:00.000+06:00

The predominant family of microcontrollers are 8-bit types since this word size has proved popular for the vast majority of tasks the devices have been required to perform. The single byte word is regarded as sufficient for most purposes and has the advantage of easily interfacing with the variety of IC memories and logic circuitry currently available. The serial ASCII data is also byte sized making data communications easily compatible with the microcontroller devices. Because the type of application for the microcontroller may vary enormously most manufacturers provide a family of devices, each member of the family capable of fitting neatly into the manufacturer’s requirements. This avoids the use of a common device for all applications where some elements of the device would not be used; such a device would be complex and hence expensive. The microcontroller family would have a common instruction subset but family members differ in the amount, and type, of memory, timer facility, port options, etc. possessed, thus producing cost-effective devices suitable- for particular manufacturing requirements.

Memory expansion is possible with chip RAM and/or ROM; for some family members there is no on-chip ROM, or the ROM is either electrically programmable ROM (EPROM) or electrically erasable PROM (EEPROM) known as flash EEPROM which allows for the program to be erased and rewritten many times. Additional on-chip facilities could include analog-to-digital conversion (ADC), digital-to-analog conversion (DAC) and analog comparators. Some family members include versions with lower pin count for more basic applications to minimize costs.

Microcontrollers

2008-11-05T01:38:00.000+06:00

Microcontroller is a computer with most necessary chips onboard. Like all other Computers it has

· A central processing unit (CPU) to execute a program.

· Some random access memory (RAM) to store variables.

· Some read only memory (ROM) to store code.

· Some input output port (I/O) for to establish a communication with keyboard, mouse or other peripherals.

One Microcontroller is dedicated to execute one program, for which the code is stored in ROM and the program does not change. The program can be locked by security bit. A Microcontroller can receive signal from a device it is controlling and control the device by sending signal to the different components of that device. For any kind of product price is a very important consideration, from that point of view it is a very low cost device. Also it is a low power IC.

Real Education

2008-11-05T01:06:00.000+06:00

Hi, this is my fate that i born in a country where i have lot of possibilities
but no chance to have go advance due to the bad organizational system!!

But i think, is this our bad luck???

We have nothing to do?
As a countryman i have also so many responsibilities to good for my country.
But why i, cant go ahead???

I know this my thinking, but this should not only be thinking.
Must be possible.
For this first we have to be educated, yes educated. The education which will help ourselves
to choice the right one.
Which will give us the path to the patriotism and honesty.
The education will lead us to think ourselves as a whole unit, not a single want.

I am waiting for the Education, and try to find it, and wish to enlighten people

Best of luck

I am Bangladeshi...

2008-10-25T03:07:00.000+06:00

I am bangali, love my contry
love to speak in bangla.
try to help my country....