Credit card

A credit card is a thin plastic card, usually 3-1/8 inches by 2-1/8 inches in size, that contains identification information such as a signature or picture, and authorizes the person named on it to charge purchases or services to his account -- charges for which he will be billed periodically. Today, the information on the card is read by automated teller machines (ATMs), store readers, and bank and Internet computers.

A credit card can provide convenience and allow you to make purchases with nearly a month to pay for them before finance charges kick in.

The bank credit-card system. Under this plan, the bank credits the account of the merchant as sales slips are received (this means merchants are paid quickly -- something they love!) and assembles charges to be billed to the cardholder at the end of the billing period. The cardholder, in turn, pays the bank either the entire balance or in monthly installments with interest (sometimes called carrying charges).

In order to offer expanded services, such as meals and lodging, many smaller banks that earlier offered credit cards on a local or regional basis formed relationships with large national or international banks.

Mobile Banking

Mobile banking is a service provided by a bank or other financial institution that allows its customers to conduct financial transactions remotely using a mobile device such as a smartphone or tablet. Unlike the related internet banking it uses software, usually called an app, provided by the financial institution for the purpose. Mobile banking is usually available on a 24-hour basis. Some financial institutions have restrictions on which accounts may be accessed through mobile banking, as well as a limit on the amount that can be transacted.

Transactions through mobile banking may include obtaining account balances and lists of latest transactions, electronic bill payments, and funds transfers between a customer's or another's accounts. Some apps also enable copies of statements to be downloaded and sometimes printed at the customer's premises; and some banks charge a fee for mailing hardcopies of bank statements.

From the bank's point of view, mobile banking reduces the cost of handling transactions by reducing the need for customers to visit a bank branch for non-cash withdrawal and deposit transactions. Mobile banking does not handle transactions involving cash, and a customer needs to visit an ATM or bank branch for cash withdrawals or deposits. Many apps now have a remote deposit option; using the device's camera to digitally transmit cheques to their financial institution.

You can also use your mobile as a credit/debit card for payments at different merchant outlets. You can shop at these outlets if they are part of the service provider's network.

Vending machine

A vending machine is an, "electronic machine used to disperse a product to a consumer after a certain amount of money has been put into the machine," as defined by Business Dictionary. 
Step 1
Load the vending machine. Prior to operation, a vending machine must be stocked with the products it will dispense to consumers. These products are often supplied by the vending machine supplier, who buys them wholesale and then sells the product at a retail price. Vending machines typically have specialized keys that a small business owner can use to access the inside. Fill each display with product and make sure the products do not become inter-tangled with the vending mechanism.
Step 2
Test the vending machine. To ensure the machine is properly loaded and ready to dispense, select one or several products and use both coin and paper money to pay for the items. Vending machines measure coins and read paper money. Each machine differs slightly, but in general, it identifies each coin with an electromagnetic field which measures thickness and diameter. Dollar bills are scanned with a laser, which transmits to a small computer that deciphers each denomination. It then calculates a balance and allows the consumer to make a choice of product. When the consumer chooses, electronic signals are relayed to a motor through an electronic console board which turns the spiral dispenser of the selected product. The machine then deducts from the balance the amount of the purchase.
Step 3
Collect the money. Vending machine providers generally do not allow a small business owner access to the money collection vault and reserve access to approved vending machine mechanics. These individuals visit on a weekly, biweekly or monthly basis. The vending machine mechanic inspects the inside and outside of the machine for damage and regular maintenance. He then opens the money collection area and reconciles the money with the transaction log. Once accounted, the mechanic splits the proceeds from the sales with the business owner.

ATM

The automatic teller machine was invented by john shepherd-Barron in year of 1960.

Features of Automatic Teller Machine:

• Transfer funds between linked bank accounts
• Receive account balance
• Prints recent transactions list
• Change your pin
• Deposit your cash
• Prepaid mobile recharge
• Bill payments
• Cash withdrawal
• Perform a range of feature in your foreign language.

Input Devices:

•       Card reader
•       Keypad

Output Devices:

• Speaker
• Display Screen
• Receipt Printer
• Cash Dispensor
• Cash Depositor

The automatic teller machine (ATM) is an automatic banking machine (ABM) which allows customer to complete basic transactions without any help of bank representatives. There are two types of automatic teller machines (ATMs). The basic one allows the customer to only draw cash and receive a report of the account balance. Another one is a more complex machine which accepts the deposit, provides credit card payment facilities and reports account information.

It is an electronic device which is used by only bank customers to process account transactions. The users access their account through special type of plastic card that is encoded with user information on a magnetic strip. The strip contains an identification code that is transmitted to the bank’s central computer by modem. The users insert the card into ATMs to access the account and process their account transactions. 

The cash dispenser is a heart of the ATM. This is a central system of the ATM machine from where the required money is obtained. From this portion the user can collect the money. The duty of the cash dispenser is to count each bill and dispense the required amount. 

A complete record of each transaction is kept by the ATM machine with help of an RTC device.

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CPU

CPU stands for Central Processing Unit. CPU or simply a processor is the most important part of the computer system.

A Typical CPU Consists Of 2 Parts:

• Control Unit
• Logic Unit
• Control Unit: This part of CPU is used to manage the operation of the CPU. It commands the various computer components to react according to the program’s instruction.
•  Logic Unit: Logic unit is also referred as Arithmetic Logic Unit (ALU). The ALU is a digital electronic circuit placed inside the CPU. 

Register: A register is a very small place which is used to hold data of the processor. A register is used to store information such as instruction, storage address and any kind of data like bit sequence or any characters etc. 

L1 and L2 Cache Memory: Cache Memory is a type of memory which is placed in the processor’s chip or may be placed separately connected by a bus. The use of Cache Memory is to store program instructions which are again and again used by software for an operation. 

Working of CPU

Whenever a data or some instruction or program is requested by the user, the CPU draws it from the RAM (Random Access Memory) and might some other hardware for the purpose.

Now before sending the information back to the RAM, the CPU reads the information associated with the task given to it. After reading the information, the CPU starts its calculation and transporting the data.

Before the data is further executed, it has to travel through the System BUS. A bus in the computer is a communication system that is used to transfer the data among all the components of the computer.

The duty of the CPU is to make sure that the data is processed and is on the system bus. The CPU manages data to make it in a correct order while arranging the data on the system bus. Thus, the action requested by the user is done and the user gets the processed and calculated information. Now when the data is processed, the CPU is required to store it in the system’s memory.

GMR

In spin valve GMR, two magnetic layers are separated by a thin (~3 nm) non-magnetic (insulating) layer. It is possible to measure and adjust the strength of magnetism between these layers.

The Giant Magnetoresistance (GMR) is the large change in the electrical resistance which is induced by the application of a magnetic field to thin films composed of alternating ferromagnetic and nonmagnetic layers. This change in resistance, in general a reduction, is related to the field-induced alignment of the magnetizations of the magnetic layers. In the first experiments, the film was composed of layers of Fe (ferromagnetic) and Cr (nonmagnetic) with typical thicknesses of a few nm and the current was in the plane of the film. GMR effects can also be obtained with the current perpendicular to the layers. The origin of the GMR is the dependence of the electrical conduction in ferromagnetic materials on the spin state of the carriers (electrons).

A spin valve structure, in its simplest form shown in Figure 5 a, consists of a magnetically soft layer separated by a nonmagnetic layer from a second magnetic layer which has its magnetization pinned by an exchange biasing interaction with an antiferromagnetic (FeMn) or ferrimagnetic layer. The operation of the spin valve can be understood from the magnetization and magnetoresistance curves shown in Figure 5 b. One of the permalloy layers has its magnetization pinned by the FeMn in the negative direction. When the magnetic field is increased from negative to positive values, the magnetization of the free layer reverses in a small field range close to H=0, whereas the magnetization of the pinned layer remains fixed in the negative direction. Consequently, the resistance increases steeply in this small field range. Magnetic multilayers of the spin valve type are used in most applications of GMR, in particular the read heads of hard discs,

Uses:

Spin-valve sensors

Hard disk drives

Magnetic RAM

biosensors

Magnetoresistive insulators for contactless signal transmission between two electrically isolated parts of electrical circuits were first demonstrated in 1997 as an alternative to opto-isolators. A Wheatstone bridge of four identical GMR devices is insensitive to a uniform magnetic field and reacts only when the field directions are antiparallel in the neighboring arms of the bridge. 

Digital osciloscope

A digital oscilloscope is a complex electronic device composed of various software and electronic hardware modules that work together to capture, process, display and store data that represents the signals of interest of an operator.

Digital oscilloscopes are often referred to as digital storage oscilloscope (DSO) or digital sampling oscilloscopes (DSO).

In its simplest form, a digital oscilloscope features six elements — the analog vertical input amplifiers, analog-to-digital converter and a digital waveform memory, a time base which features a triggering and clock drive, the circuits for waveform display and reconstruction, the LED or LCD display, and the power supply.

Digital oscilloscopes periodically samples a time varying analog signal and stores in the waveform memory the signal’s values in correlation with time.

Using an internal clock, digital oscilloscopes chops input signals into separate time points. The instantaneous amplitude values are then quantized by the oscilloscope at those points. The resulting digital representations are then stored in a digital memory.

At a predetermined clock rate, the display is regenerated from the device’s memory and is consequently viewed as connected dots or a series of dots. Digital Oscilloscopes provides powerful features on how they trigger the digitized data from its memory.

Some of the advantages of a digital oscilloscope over analog oscilloscope include the scope’s ability to store digital data for later viewing, upload to a computer, generate a hard copy or store on a diskette and its capacity to instantly make measurements on the digital data.

After a trigger event, digital oscilloscopes can be made to display the waveforms as compared to an analog oscilloscope that needs to be triggered first before it starts a trace.

A digital oscilloscope also has the ability to examine digitized information stored in its memory and make automatic measurements based on the selected parameters of the user, such as voltage excursion, frequency and rise times.

It can also display similar captured data in various ways. This capability is attributed to the presence of more captured data than what shown on the screen. It also offers the flexibility of providing a vast array of storage, processing and display options, such as graphics and one-quarter and one-half screen displays and multiple step processing programs.

A digital oscilloscope is ideal for displaying intricate signal waveforms where calculations and measurements on specific portions of the waveforms must be made to provide numerical and waveform output displays which reflects the chosen parameters of the waveforms.

The two general categories of digital oscilloscopes are single shot oscilloscopes and random interleave or equivalent time sampling oscilloscopes.

Single shot oscilloscope starts real-time sampling of an event after a trigger condition has been satisfied. The speed of the analog-to-digital converter determines the limitations of the sampling speed of single shot oscilloscopes. The size of the device’s acquisition memory, which receives the output from the converter, limits the time on which a single event can be sampled.

Meanwhile, random interleave oscilloscope or equivalent time sampling oscilloscope relies on sampling repetitive events at different points over certain periods of time.