SMPS

SMPS

Power is important for the working of any electronic device, such as computers. The Power Supply is essential for the functioning of the computer and its conditional components. Power issues probably are more responsible for more PC Problems than any other single source.
                                  A Switched Mode Power Supply (SMPS), is an electronic power supply unit. It helps to convert the input power to a supply unit. It helps you to convert the input power to a controlled Voltage. A computer works on DC power supply; however, the power socket provides you with AC power supply.
                                              

Fig: SMPS

Power Supply:
The power is supplied to the computer in two stages. In the first stage, the power is transmitted to the computer through a power transmitted to the computer through a power cord from the power socket. In the second stage, the internal power supply transforms this standard household electricity into the form that the computer needs.
Elements of Power Supply:
There are three main elements in a basic power supply namely Transformer, Rectifier and Filter Depending on the requirements of the user.
1. Transformer: It converts the AC Line voltage to a more appropriate voltage level according to the needs of the circuit to be powered. The AC Line voltage is not suitable for electronic circuits. Most of the circuits require considerably lower voltage while a few require higher voltage.

2. Rectifier: It Prevent the occurrence of alteration between the transformer and the AC line. It also forces the current to flow in one direction is known as rectification and the circuit that accomplishes this task is known as the rectifier.

3. Filter: It reduces the pulses from the rectifier to a much smaller ripple voltage. A properly designed filter provides a DC output voltage with only a small AC ripple.
                                                        

Types of Power Supply:
In the reference to electronic devices, power supply can be classified into two major categories:
1. Liner Power Supply
2. SMPS

1. Liner Power Supply: - A Liner Power Supply powered by AC, uses a transformer to convert the voltage from the mains to a different, usually lower voltage. If you are using it to produce a DC, then you need to use a rectifier. To smooth the pulsating current from the rectifier, a capacitor is used. But still there is some small periodic deviation from smooth direct current will remain which is known as a ripple. The unregulated power supply produces the voltage that varies depending on the load and on variation in the AC supply voltage.

2. SMPS: - In SMPS, to obtain DC voltage, the AC mains input is directly rectified without the use of a transformer. Then, a high speed electronic switch is used to slice this voltage into small pieces. As the power output requirements increases, the size of these slices also grows.
                                                        

Power Connectors:
Power Connector is an electrical connector that is used to carry DC or low frequency AC power with the help of power connectors, the power supply unit provides current to the different components of a system which includes motherboard, hard disk drive, floppy disk drive and different other components.
                                                         

Fig: Different Types of Connector

AT Power Connectors:
AT (Advanced Technology) power connector have two 6-wire connectors named P8 and P9 which are to be connected to the motherboard with black wires facing each other, inside. The various form factors of the power supply such as PC/XT, AT, Baby AT and LPX use a pair of 6-wires connectors known as AT style connectors to connect the power supply to the motherboard.

ATX Power Connectors:
ATX (Advance Technology Extended) Power Connector is a 20-pins connector which outputs 6 types of voltages. ATX style power connectors are used by ATX/NLX form factors.

PIN Signal  Colour1 Colour2
1 3.3 v Orange              Violet
2 3.3 v Orange              Violet
3          Ground Black Black
4 5 v Red Red
5 Ground Black Black
6 5 v Red Red
7 Ground Black Black
8 PW-ok Orange Orange
9 5 v – SB Brown Brown
10 12 v Yellow Yellow
11 3.3 v Orange Violet
12 -12 v Blue Blue
13 Ground Black Black
14 PS – on Green Grey
15 Ground Black Black
16 Ground Black Black
17 Ground Black Black
18 -5 v White White
19 5 v Red Red
20 5 v Red Red

Standard Peripheral Power Connector:
It is also known as “4-pin Molex”. The 4-wire connectors are used by the disk drive power connectors.
Pin Color Description
1 Yellow +12v
2 Black Ground
3 Black Ground
4 Red +5v


Floppy Drive Power Connector:
It also known as mini-plug are used in the 3.5-inch floppy disk drive.

Power Switch:
The older form factor desktop PC/XT cases had the power switch at the back of machine, usually on the right side of case. The switch was actually inside the power supply itself, with a hole cut out in the case. So that it could be reached from the outside.

Power Supply Fan:
It is the primary source to dissipate heat from the entire computer, since the earliest computers. The fan is traditionally located at the rear of the power supply, and special vents are provided for it in the case of the supply itself to allow for it to exhaust. Most fans use +12v power to operate, despite the fact that the wires that run to them are normally red for the +12v line, and black for the ground. The standard size of a computer cooling fan is about 3.25 or 80 mm sq.

Cooling System:
For cooling the system components, drive coolers and baby coolers are used. The drive coolers contain a fan that blows the air and cools the hard disk. They are attached to the hard disk drive using a thermal conductive tape. The bay cooler is also used for cooling the hard disk. the bay cooler has fans to cool the device which is mounted in the "5.25". The hard disk is placed in the bay.

Types of Cooling System:

a) Fan:
The system power supply and the system case contains a fan in it that helps conduit air flow in or out from the system case. This helps in cooling the components located inside the system case and prevents them from being damaged. To cool the microprocessor, you can attach a fan on it.

b) Heat Sink:
A Heat Sink is an object that absorbs and dissipates heat from another object using thermal interns of the computers a heat sink absorbs heat from the processor and the air flowing over the heat sink cools the microprocessor. it is used to cool the microprocessor and other chips on the system.

Tips and Tricks of Networking

Subnetting:

The technique of dividing a network into logical subnetworks or subnets to avoid network traffic is called subnetting.This can also be stated as splitting a single IP address into many subnetwork addresses. It allows you to manage distinct network under a single class address. This can be done by shifting bits from the Host IDs to the network ID. Subnetting allows you to more networks with fewer hosts because network ID. In this way, you can connect to the Internet with the single shared network address. In subnetting, network IDs are merged with the host ID bits or few of the Host IDs that are used as subnets. According to the standard IP address classes, there are only three possible network ID sizes: 8-bits for class A, 16-bits for class B and 24-bits for class C. subnetting allows you to use the limited space of an IP address efficiently.

SUBNETTING CAN BE PERMORMING IN TWO WAYS:
A) Fixed length subnet mask (FLSM)
B) Variable length subnet mask (VLSM)

Subnets:
A network that exists within the class A, B or C network is called a subnet. It can also be defined as a network within a network. Subnets are created to extend network IDs by using one or more class A, B and C addresses. Therefore, subnets can have a network ID of any length. All devices that have IP addresses with same prefix are defined as subnets. These are connected to the Internet by using the same shared network. While designing a subnet, always specify the maximum number of subnets that are required, and ensure that enough host addresses are available.

Supernetting:
Supernetting is defined as the combination of all network routing commands in a single routing table entry. It is commonly called Classless Inter-Domain Routing (CIDR). It is designed to solve the problems such as, wastage of many addresses in the class addresses described by the classful address. Supernetting resolves many problems arising because of subnetting, such as, all zeroes, and all ones marks in the IP addresses. Like subnetting, can take any number of host IDs. The difference between supernetting, the host and network IDs are merged, while in subnetting the IDs are split. The CIDR masks for classes A, B and C are /8, /16 and /24.

CIDR value:

/8= 255.0.0.0                                      /9=255.128.0.0

/10=255.192.0.0                                 /11=255.224.0.0

/12=255.240.0.0                                 /13=255.248.0.0

/14=255.252.0.0                                 /15=255.254.0.0

/16=255.255.0.0                                 /17=255.255.128.0

/18=255.255.192.0                             /19=255.255.224.0

/20=255.255.240.0                             /21=255.255.248.0

/22=255.255.252.0                             /23=255.255.254.0

/24=255.255.255.0                             /25=255.255.255.128

/26=255.255.255.192                         /27=255.255.255.224

/28=255.255.255.240                         /29=255.255.255.248

/30=255.255.255.252                         /31=255.255.255.254

/32=255.255.255.255

For example:

IP Address =       10.1.1.1/14

Subnet mask =     255.252.0.0

IP Address =       172.16.1.1/20

Subnet mask =    255.255.240.0

IP Address =       192.168.10.1/26

Subnet mask =    255.255.255.192    

and so on...

to be continued......................

Computer Basic

A computer is an electronic device that stores information processes the data and gives the necessary output. It also helps in searching information and retrieving data.

Advantages:
1] Computer helps in saving time.
2] Computer is fast so ease in working.
3] computer nowadays are used for educational, medical, banking etc.
4] Computer has high working speed.
5] Computer is accurate and error free.
6] Computer helps in saving large data.

Disadvantages:
1] Computer if gets corrupted all the data is lost.
2] computer creates unemployement by consuming all the work in it.
3] Computer cannot take any decision on its own.
4] Computer is not intelligent hence it depends on human beings.
5] Man has adapted laziness in itself due to continuous use of computers.
6] computer crimes e.g hacking the data.


• Hardware is a part of the computer that has a physical structure, such as keyboard or mouse. It also includes the internal parts of the computer.

Types of Hardware :

a) Input Devices: Input Devices are the one which helps in giving instructions or information to the computer.
Eg] Keyboard, Mouse, Joystick, OCR, OMR, and MICR etc.

b) Output Devices: Output Devices are part of hardware which shows the output of the instructions passed to the computer.
Eg] Monitor, printer, plotter etc.

c) Storage Devices:  Devices which can store electronic data are known as storage devices. Eg] Hard Disk, CD-ROM, Floppy Disk etc.

d) Processing Devices: Devices which can process the data and give output are known as processing devices. eg: CPU.

• Software is a set of instructions that informs the hardware about its working. It is what guides the hardware and tells it how to accomplish each task. Some examples of software include Web Browsers, Games, and Word processors.

Types of Software:

1. System Software:  The System Software is collection of programs which helps the computer to control, and manage the resources and to keep a check on its capability itself.
Eg] Operating System, Compilers, Interpreter, Assemblers etc.

2. Application Software:  Application Software is particularly  made to get the solution to a particular problem.
Eg]MS Office,MS Word, MS Excel etc.

• How to get started with your computer?

First of all there is a list of tasks he/she want to perform in order to set up your computer. Following are the task include:

• Creating/adding new users to your computer
• Transferring files from one computer another
• Backing up your files
• Personalizing windows

Click to open getting started.

to be continued....................

Secrets of Computer

Wireless

The Institute of Electrical and Electronics Engineers (IEEE) an organization that defines industry-wide standards in the fields of electrics and computing has set guidelines or standards for wireless networking commonly called the wireless fidelity (WI-FI) standard.

Basic of wireless Networking:

For the distribution of data, the wireless network standard uses cellular radio signals or links to provides network connectivity to PCs and laptop through a transmitter/receiver unit (transceiver), generally known as an access point or wireless access point (WAP). WAP transmit and receiver signals to and from wireless network adapters.

Following are vital factors of it:

1) Weather condition between satellite and PC may reduce the power of the signal in a network because of the interface caused by induced electromagnetic waves due to cloud collision. This distorts the signals, which in turn affects the transmission of the signal over a network.

2) Security

3) Speed

• Hardware Requirement of a wireless Network:

Wirelesses networking capability of one form or another are built into many modern computing devices. Infrared transceiver ports have been made standardized computers, wireless Ethernet and Bluetooth capabilities are increasingly becoming popular as integrated components, or can easily be added by using peripheral component interconnect (PCI) or personal computer memory card International Association (PCMCIA) add-on cards.

• Wireless Access Point (WAP):

WAP is a device that sends and receives data signals that are used to establish a connection between two devices in a network. WAP is also referred to as a transceiver because it is used to transmit and receive data signals. A transceiver enables a user to connect two or more wireless devices and communicate with other users. WAP also acts as the point interconnection between WLAN.

    WAP can be divided into two types, hardware access point and software access point. Hardware access point is to define as a physical device used to establish a connection between two devices and software access point is defined as computers that include a wireless network interface card.

to be continued.........................

Networking Basic

Network:
A network means a set of connected computers. It consists of two or more computers that are connected to each other for the purpose of sharing resources and information (printers, scanner, file servers and other). All computers are connected to each other through wired or wireless channel is known as a network.
Example: Internet- connecting Billions of people all over the world.

Different Types of Network:
o Area Network
o Network Protocol
o Network Design
o Network Topology
o Wired or Wireless

Area Network:
Two or more computer connecting together for sharing information is called network.
Network is a combination of different hardware and software.

Computer network are categorized into different ways:

 Local Area Network (LAN)

 Metropolitan Area Network (MAN)

 Wide Area Network (WAN) 

 Local Area Network is a collection of computers and network devices which is connected to each other within a limited area or small geographical area (such as home, school, and building etc.) and capable of sending as well as receiving the data i.e. Printer, scanner and storage device.  

 Metropolitan Area Network is a type of network, which consists of a large network across several buildings in the same town or city. Generally it connects several LAN s together to form a large network i.e. MAN

 Wide Area Network is a network which occupies large geographical area. There is no limitation to space or area (building, town, and city). It is a combination of LAN s as well as MAN s network together to form WAN. The best example is Internet in which people can interact with other person across the country (ex- video calling, email and others).

TCP/IP MODEL:

Understanding TCP/IP protocol suite:

Transmission control protocol/Internet protocol is the two way communication protocol, which is used to send and receive data from one computer to the other over a network. TCP/IP uses the client/server model of communication in which a user (client) requests the host computer (server) for services. Thereby establishing communication a TCP/IP protocol is not just a single networking protocol, but a collection of protocols, which are used for defining the standards for working on the internet. An IP address is used in a TCP/IP network.

Layer of TCP/IP:

The framework for the TCP/IP protocol suite is defined as a five layer model similar to OSI model which has 7 layers.

1.     Application Layer
2.     Transport Layer
3.     Network Layer
4.     Data-link Layer

1. Application Layer:

This layer is similar to the session, presentation and application layers of  the OSI model. The following are some protocols used in this layer:
§  Hypertext Transfer Protocol (HTTP): It used in World Wide Web (www).
§  File Transfer Protocol (FTP): It Transfer files between hosts and client.
§  Trivial File Transfer Protocol (TFTP): It acts as a base for FTP and is used for uploading
    files.
§  Telnet: It helps in establishing a connection on client computer in a terminal emulation
    code. (Telecommunication network).
§  Simple Mail Transfer Protocol (SMTP): It transfers of mail.
§  Domain Name System (DNS): Protocol that uses names rather than number for
    accessing hosts.

2. Transport Layer:

It is the layer where the sending and receiving of data packets takes place between two hosts. The TCP and UDP (user datagram protocol) define here:
Transmission Control Protocol: It refers to a connection- oriented protocol, which is sequentially, discarding duplicate data, and resending of discarded host packets of data. Data packets transmitted by TCP remains in the same order as the transmitted data packets flow in a single stream. TCP also ensures the transmission of data packets between the hosts.
User Datagram Protocol (UDP):
It refers to a connectionless, unreliable protocol, which is used for streamlining of data. The delivery of data packets to the target host is not ensured in this protocol. UDP is best applied in DNS. It is faster as compared to TCP.

3. Network Layer:

      The Network layer, also known as the internet layer is the layer where data are      addressed. This layer is responsible for carrying data from the source to the target. Other protocols used in the working of network layer are:
Internet Protocol: Refers to a protocol used for routing of data to various IP addresses in form of the datagram. IP does not send a datagram (a group of packets, consisting of data or information) in the order in which it received and also does not reorder data while sending the datagram back to the sender.
Address Resolution Protocol (ARP): It helps to convert IP address to Media Access Control (MAC) addresses, or the physical address present on Network Interface Card (NIC) of each device.
Reverse Address Resolution Protocol (RARP): It helps in connecting a computer to a network for the first time. RARP determines the IP address from a known MAC address.
Internet Control Message protocol (ICMP): It acts a base for ping commands. This protocol is used to report problems with the delivery of IP datagrams within an IP network.
Internet Group Management Protocol (IGMP): It helps in multicasting, the data to multiple IP addresses at the same time.

4. Data-link Layer:

The Data-link layer provides a link to connect the node to the network. This layer is used to move packets (known as data frames) between the network layer interfaces of two different hosts using the same link. The process of transmitting and receiving packets from a given link can be controlled. It performs functions such as physical addressing (adding a header to the frame). If two or more devices are connected to the same link, then the layer having control over the link is determined by the Data-link layer.