ATM Machine
Fig. 1: An Automated Teller Machine (ATM)
The first Automatic Teller Machine or ATM was
built in New York City in 1939. But the present form has been evolved in last
20 years. An ATM is also known as Automated Teller, Cash Point, Banking Machine
or Money Machine. It is highly sophisticated engineering marvel accessible to
everybody for telling a person’s banking information, payments and withdrawing
him the money he demands.
Construction & Working
Apart from the technology for money withdrawal, an
ATM is equipped with state of the art security system that guarantees a safe
and secure transaction and renders the machine pretty much impregnable.
The procedure begins by insertion of an ATM card
by the card holder. The magnetic tape on the card is read by two sensors. The
first sensor checks for genuineness of the card, while the second one reads the
bank account number and password for onward matching with password manually
keyed in.
Fig. 2: Card reading sensors
Once the password is confirmed the ATM connects
to the bank's network which gives machine its marching orders and remotely
controls access to the on board vault. The trays in the vault hold bills with different
denominations with up to a thousand bills in each. One tray is left empty for
deposits.
Fig. 3: Money in vault
The cheque or money deposited with an envelope goes
into a bin and is manually sorted later. Some ATMs can take the deposits without an
envelope. They are able to count the incoming bills and refill themselves.
For withdrawals, vacuum driven suction cups grab
one bill at a time and feed it to a roller system. Drawing one bill at a time from
the vault, prevents the machine from over payment.
The bills pass through rollers with sensors to check
their length, width and the thickness of the bill about the size of a coating
of paint. If it senses the bill thicker, it is considered as two bills stuck
while any thinner, tells the machine that the bill is worn or fake and sends it
to the reject bin. That’s when the user hears a pause during a counting sound.
The transaction is recorded by the bank and the machine is ordered to release
the card.
Fig. 4: A bill passing through rollers
Security
The ATMs construction involves more than a 100 kg
steel which makes it heavy and impregnable. The machine is able to withstand 22
tons of impact. The vaults are designed in a way that they can survive an
assault for a time long enough till the police arrives. In the event of a breach of
vault security, there are explosive canisters of die that explode and ruin the
money inside as soon as the vault seals are broken. There is also an on-board
GPS to track the machine in the event of robbery.