Barcode readers read cards who have alternating light and dark bars of varying widths. These bars are read by an optical scanner. The width and spacing with the bars is dependent upon the bar code protocol used. The advantage of this technology is that it is cheaply produced. This factor, however, also provides a disadvantage, mainly because it makes it easy for people to duplicate real bar codes by photocopying them.
The passport reader reads a bit of magnetic oxide tape which is laminated around the back of a card. This type of card is pretty inexpensive, but is vulnerable to wear, and be misread. Also, it is usually reproduced for fraud, though much less easily as the barcode badges.
Weigand readers read cards that have embedded ferromagnetic wires. The ferromagnetic wires a strategically placed to produce an identification number. These cards contain the advantage of not being vulnerable to wear, unlike the barcode and magnetic stripe cards, and they are generally very difficult to duplicate. Consequently, weigand readers became popular at some point. Now they are replaced by proximity readers.
A passport reader does not use the weigand technology, community . is still called a "Weigand reader." The proximity reader radiates a 1" to 20" electrical field around itself. When a proximity card is presented to the reader, the electrical field excites a magnetic coil inside card. The coil charges a capacitor, along with the capacitor charges a circuit. The circuit provides card number to the coil, which sends it to the reader.
The last audience the smart reader. These readers have the latest technology within the form of an imbedded microprocessor and memory. It differs from the proximity card in that the devspky89 function from the microprocessor would be to give the various readers the identification number. There are two kinds of smart cards: contact and contact-less. A contact smart card has eight contacts, which must touch contacts around the reader. The contact-less smart badges implements the identical radio-based technology as the proximity card, with the exception that it is run on a higher frequency. These cards don't even have to be studied out of your wallet to be read. Smart badges happen to be targeted by criminals, who tamper together before they're sent to customers, stealing numbers and knowledge from them.
These five different forms of usb magnetic card reader each have their own pros and cons. The five types are; Barcode, Magnetic Stripe, Proximity Card, and Smart readers. The card reader may be developed as time passes, with efforts to ensure safety from fraud, and convenience for users.