Douglas Adams

We are stuck with technology when what we really want is just stuff that works.

Albert Einstein

It has become appallingly obvious that our technology has exceeded our humanity.

Jose Manuel Rodriguez Delgado

Can you avoid knowledge? You cannot! Can you avoid technology? You cannot! Things are going to go ahead in spite of ethics, in spite of your personal beliefs, in spite of everything

Sergey Brin

Technology is an inherent democratizer. Because of the evolution of hardware and software, you’re able to scale up almost anything. It means that in our lifetime everyone may have tools of equal power.

Douglas Adams

Most of the time spent wrestling with technologies that don't quite work yet is just not worth it for end users, however much fun it is for nerds.

Saturday, October 25, 2014

What is the HDMI Interface

HDMI (High-Definition Multimedia Interface) is a standard for creating Video and audio  connections between high-definition electronic devices. HDMI supports two-way digital communication between the two devices and the video display with one cable. HDMI is a compact video/Audio interface for transferring uncompressed video data and compressed or uncompressed digital audio data for HDMI compatible device.
 
HDMI supports standard, enhanced, or high-definition video, plus multi-channel digital audio on a single cable. It transmits all ATSC HDTV standards and supports 8-channel digital audio, with bandwidth to spare to accommodate future enhancements and requirements. All HDMI jacks are HDCP compatible. HDMI can be transmit Data using TMDS (Transition-minimized differential signaling ) protocol up to Up to 18 Gbit/s in HDMI 2.0

Friday, August 22, 2014

GSM Network Components Lesson 2

GSM network consists of several functional entities.Those functions and interfaces are defined. The GSM network can be divided into following network components.

  1. Mobile Station ( MS )
  2. Base Transceiver Station ( BTS )
  3. Base Station Controller ( BSC )
  4. Mobile Switching Center ( MSC )
  5. Authentication Center ( AUC )
  6. Home Location Registers ( HLR )
  7. Visitor Location Registers ( VLR )
  8. Equipment identity Register ( EIR )
1) Mobile Station ( MS )

Mobile Station (MS) is the user equipment in GSM System. Mobile station consists of the physical equipment and hardware related software. such as the radio transmitters, display, digital signal processors, and the SIM card. It provides the air interface to the user in GSM networks.

Mobile Station consists of following components

Mobile Termination ( MT )
Mobile termination offers common functions, such as Radio signal Transmission and receiving, handover, speech encoding and decoding, Error detection and correction,signalling and access to the SIM card. The IMEI code is attached to the MT. 

Terminal Equipment (TE)
Any device connected to the MS offering services to the user.

Terminal Adapter (TA) This is provides access to the MT. Communication between the TE and MT over the TA takes place using AT commands.

Subscriber Identity module (SIM)
This is a removable subscriber identification ( SIM card ) token storing the IMSI a unique key shared with the mobile network operator. SIM Card provides personal mobility so that the user can have access to all subscribed services irrespective of both the location of the terminal and the use of a specific terminal.

2) Base Transceiver Station (BTS)


BTS is a telecommunication infrastructure used to facilitate wireless communication between subscriber device ( MS ) and Base Station Controller (BSC).

BTS consists of following parts

Transceiver (TRX)
Transceiver (TRX) which handles transmission and reception of signals sending and reception of signals to or from higher network entities. 

Combiner
Combines feeds from several TRX so that they could be sent out through a single antenna. Allows for a reduction in the number of antenna and feeders used.

Power amplifier (PA)
Power amplifier which aids in signal amplification from TRX for transmission through the antenna.

Combiner
Duplexer which is used for separating transmitting and receiving signals from the antenna and an Antenna which is an external part of the BTS.

Sector Antenna
Transmitting and reserving signals 

Alarm extension system
Collects working status alarms and external alarm (door,main power ,rectifier alarm )  of various units in the BTS and extends them to operations and maintenance (O&M) monitoring stations.

Base band receiver unit (BBxx)
This functions are frequency hopping, handover and signal DSP.

3) Base Station Controller (BSC) 


BSC manages the radio resources for BTS. BSC handles Radio channel setup, Frequency hopping, and handovers. The BSC is the connection between the BTS and the MSC. BSC transmit the data to the BTS using Abis interface. BSC assigns frequencies and time slots for the Mobile Station (MS). The BSC also handles intercell handover. It controls the power transmission of the BSS and Mobile Station (MS) in its area. The function of the BSC is to allocate the necessary time slots between the BTS and the MSC. It is a switching device that handles the radio resources.

BSC Function 
  1. BTS  is connected to BTS and MSC
  2. Radio resource management
  3. Reallocation of frequencies
  4. Control of frequency Hopping   
  5. Power control
  6. Inter-cell handover
  7. Time delay measurement of the received signals from MS with respect to BTS clock
  8. Performs traffic concentration to reduce the number of lines from BSC to MSC
  9. BSC performs call processing
  10. TRAU are generally located at the site of MSC
  11. BTS configurations as per requirement
  12. Data from OMC and can be down loaded to BSC


Saturday, August 16, 2014

Characteristics of a Sine Wave

Electrical sin wave form graph is a showing the variation of voltage or current. The horizontal axis shows the passing of time, progressing from left to right. The vertical axis shows the quantity measured ( voltage, ampere or Power ). There are six must important characteristics of sine wave.


RMS value 
Root mean squared ( RMS ) value is the value of the equivalent direct voltage ( DC ) which would provide the same energy to a circuit as the sine wave measured. That is, if an AC sine wave has a RMS value of 230 volts, it will provide the same energy to a circuit as a DC supply of 230 volts.

RMS value Equation 

RMS = Peek X 0.707

Example
Peek value or Max value = 326 V

RMS = Peek X 0.707

 RMS = 326 X 0.707

RMS = 230.48 V

Average Value or mean value 
This is normally taken to mean the average value of only half a cycle of the sine wave.


Mean value Equation 

mean = V Peek  X 0.637

Example
Peek value or Max value = 326 V

mean = V Peek  X 0.637
mean =  326 X 0.637
mean = 207.66 v


Peak to Peak value
Peak to peak (pk-pk) is the difference between the maximum positive and the maximum negative amplitudes of a waveform. 

Peek to Peek value  

VPP = Peek + Peek 

Example
Peek value or Max value = 326 V

VPP = Peek + Peek 

VPP = 326+ 326

VPP = 652 v

Instantaneous Value 
Instantaneous value of an alternating voltage is the value of voltage at one particular instant time. The value may be zero if the particular instant is the time in the cycle at which the polarity of the voltage is changing. It may also be the same as the peak value, if the selected instant is the time in the cycle at which the voltage stops increasing and starts decreasing. There are actually an infinite number of instantaneous values between zero and the peak value.

Instantaneous value Equation

v (t) = VMax sin (w t )

w = 2 x p  x f  or  w = 2 x p / T

v (t) = VMax sin (2*p*f *)

Amplitude 
Amplitude is the difference between the maximum positive and the X axis of a waveform. It is equal to peek value.

Periodic Time
periodic time is that amount of time that elapses from the start of a occurrences until the commencement of the next identical happening.

T = 1/f 

T = Periodic time
f  = Frequency 

Frequency 
Frequency is the number of occurrences of a repeating event per unit time.

F =1/T

f  = Frequency
T = Periodic time




Friday, August 15, 2014

Introduction of Global system for Mobile communications ( GSM ) Lesson 1

GSM is a Digital wireless Mobile telephony system that is widely used in the world. GSM use a combination of both the FDMA ( frequency division multiple access ) and TDMA (  Time division multiple access ). using this both combination can be transmit more channel of same time.

Saturday, May 17, 2014

Not showing My Computer Icon on Desktop in Windows 8 & 8.1

My computer icon is most important icon in windows operating system. In previous Operating Systems, like Windows 7 and Windows XP you can go to start menu and Right click on My computer icon and Show on Desktop for My Computer icon to show it in desktop. But the traditional start menu also missing in Windows operating systems, therefore ‘Show on Desktop’ is not available here.

How to Show My Computer Icon on Windows 8.1 & 8 Desktop
It is easy and few steps, I’ll be explaining the steps by steps with screen print.

   1. Right click in any empty space on the Desktop and click Personalize from the popup menu.


   2. Change desktop icons link on the left pane.


3. On the Desktop Icon Settings dialog box, select the Computer check box so there is a check mark in the box and ok. you can use this method such as the Control Panel and Recycle Bin. 


Now you can see your My Computer icon on your windows 8 Desktop. 

Thursday, May 15, 2014

Practical Resistor value calculation

Resistor is a passive electrical component that reduce flow of electrical current in an electronic or Electronics circuit. resister has a linear IV ( V=IR ) characteristicmeaning that the voltage across the resistor is directly proportional to the current through the resistor.
Resisters's 103 Symbol

 Resistor In Ohms  Unit  Symbol
 1  Ohm      Ω
 1,000  Kilo Ohm     KΩ
 1,000,000  Mega Ohm     MΩ
Resistors practical value

Resistors only come in specified values. These values are spread across multiples of ten.

1.21.5 1.8 2.2 2.7 3.3 3.91 4.7 5.6 6.8 8.2
After that, the cycle repeats, but a power of ten higher.

Resistor Color code

Color
Significant figures
Multiplier
Tolerance
Black×100
-
Brown1×101±1%
Red2×102±2%
Orange3×103
-
Yellow4×104
-
Green5×105±0.5%
Blue6×106±0.25%
Violet7×107±0.1%
Gray8×108±0.05%
White9×109
-
Gold×10-1±5%
Silver×10-2±10%
None
-
-
±20%

Example Calculation
Eg 1
Red      Red    Orange   Gold    
  2               2            000        ±5% 
  22000 Ω  ±5%    Or    22 KΩ

Eg 2
Blue      Gray   Brown    Silver
  6                8            0            ±10% 
  680 Ω  ±10% 

Power rating Of Resistor 
  power rating of a resistor is the specification given with a resistor that serves to tell the maximum amount of power that the resistor can withstand. When current passes through Resistor, it normally generates heat. there for we have to find suitable wattage resistor for the Electronics circuit.
 Let's look at examples of resistors and the power ratings we would need for them for you to get a practical idea:

Resister Value                    820 Ω
Resister between Voltage     12V

P = V2 / R

P =12 x 12 / 820
p = 0.1756

1/4 watt resistor would suffice and be suitable for the circuit

The common standard power ratings of resistors are 0.25W, 0.5W, 1W, 2W, 5W, 10W and 25W. So the circuit designer must choose accordingly for the circuit.

Resistor Watt range with physical size  




Tuesday, May 13, 2014

How to configure Thomson TG 585 V8 Router for bridge mode ( Ooredoo Thomson Router configure for Wifi access point )

How to configure your Adsl Thomson  TG585 v8 Router ( Qatar Ooredoo white color Router ) for wifi access point. It is very simple step. I think now you have a Thoson   TG 585 V8 Router also if you don't know your Thomson Adsl router password you have to find Ethernet pach code. last think is download Thoson TG 585 V8 router brige mode configuration file. Click below  Mediafire link and download configaration file 

Download Thomson TG 585 V8 configuration File 

Thomson Router IP adress       192.168.1.254
Thomson Router User name    Administrator
Thomson Router Password      connect2th

Connect to your router through Wifi or using Ethernet cable. Now open your internet browser and type 192.168.1.254 IP address go to router logging web interface. then enter user name and password after you are direct to Thomson TG 585 V8 router configuration page. then upload configuration file .flow the below step to upload configuration file or see the video.

Thomson Gateway -------> Configuration ---------> Save or Restore Configuration ------> chose file
------> Restore configuration now

Now your router ready to user as a wifi access point. but there is a common wifi name and logging password. flow the below step for password change or see the below video. It is current password is srilanka

Home Network -----> Wireless ------> configure -------> then change WEP Encryption Key and Network Name (SSID) and click apply button
Thomson TG 585 V8 Bridge mode configuration video


Thomson TG 585 V8 Router password change

 

Thomson TG 585 V8 Router picture


Friday, February 21, 2014

How to install and align free to Air satellite Dish Without a Meter

Buy below Equipment 
  1. Ku Band or C band satellite Dish 
  2. Ku Band or C Band LNB  
  3. Free to Air Satellite Receiver   (MPEG 4/DVB-S2 is better )
  4. RG6 Cable ( Antenna coaxial cable )
  5. Taper seal F connector 2 ( connector for coaxial cable )
  6. Find a Drill Machine, Screw drive , Spanner wrench , Compass 
Select a your Satellite 
Visit a www.lyngsat.com  select your favorite satellite. I'm select INSAT 4B for the continue lesson. write down transponder frequency, Symbol Rates and polarization ( vertical or Horizontal ) 

My selection details 

Transponders   10990,11070,11150, 11490,11570
Symbol Rate    27500
Polarization      V

Find your reception details and Dish size 
Visit a www.satbeams.com/footprints find your reception details. you have to write down Elevation Angle,Magnetic Azimuth, LNB tilt and recommend dish size.

My selection data for INSAT 4B for Sri Lanka

Elevation Angle 73°
Magnetic Azimuth 119°
LNB Tilt 60
Dish size For Ku Band 70 cm


Assemble Dish
Assemble dish using manual. and connect F connector for coaxial cable.

Select a location for your Dish
selection location should be direct line of sight in the direction of the satellite and free of obstruction. Generally high location such as a rooftop or side of wall are used. The dish should be fixed at the mounting point. connect LNB and receiver using Coaxial Cable.

Configure your Receiver 
Turn on the Receiver and TV. Enter the receiver setup mode and  find Transponder edit menu and enter Transponder Frequency , symbol rate and  Polarization. Again enter the receiver setup mode and navigate the menu option until you find the signal strength screen. 

Dish align method 
  Keep your partner in front of the TV. keep communication both of you until finish the dish alignment. obtain correct elevation azimuth and LNB Angle setting foryour Dish from www.satbeams.com/footprints web site.
  Locate the Dish correct Azimuth using compass. Aline the Dish physically very show arc. until it is pointed
in approximately the correct direction. Ask your partner to call when the signal strength indicator begins to move. Turn the dish in one direction just a degree at a time and wait for your partner to respond after each movement. Repeat until the signal strength peaks and then begins to fade again.
    Move the dish slowly back in the other direction, until your partner tells you the signal has once again peaked. Tighten the bolts on the mount to finalize the azimuth. Loosen the elevation bolts slightly so you can angle the dish and repeat the process until you have got the elevation fine tuned. Your signal strength should be at least at 80. Now you are dish align completed.  

Dish align video this video helps that how to align Satellite dish  

Useful web site
www.satbeams.com


Friday, January 10, 2014

LKTips English to sinhala word translation pop up dictionary After installing this extension

LKTips is an easy-to-use pop-up dictionary ( English to Sinhala ) add-on for Firefox and Google chrome. after installation just over the mouse pointer on the word it will be translate to sinhala.

Click Here to move LKTips Download Site


Saturday, November 24, 2012

Ohm's law

Ohm's Law    
For a fixed metal conductor, the temperature and other condition remaining constant the current through it is proportional to the potential difference between conductor ends.

V/I = Constant

V= IR

V  = volt 
 I  = Current
 R = Resister of the conductor between the two pints considered

we can apply V=IR  Linear resistors only.