A reader radiates a 1" to 20" electrical field around itself. Cards use a simple LC circuit. When a card is presented to the reader, the reader's electrical field excites a coil in the card. The coil charges a capacitor and in turn powers an integrated circuit. The integrated circuit outputs the card number to the coil, which transmits it to the reader.
Wiegand card technology is a patented technology using embedded ferromagnetic wires strategically positioned to create a unique pattern that generates the identification number. Like magnetic stripe or barcode technology, this card must be swiped through a reader to be read. Unlike the other technologies, the identification media is embedded in the card and not susceptible to wear. This technology once gained popularity because it is difficult to duplicate, creating a high perception of security. This technology is being replaced by proximity cards, however, because of the limited source of supply, the relatively better tamper resistance of proximity readers, and the convenience of the touch-less functionality in proximity readers.
A card reader is a data input device that reads data from a card-shaped storage medium. The first were punched card readers, which read the paper or cardboard punched cards that were used during the first several decades of the computer industry to store information and programs for computer systems. Modern card readers are electronic devices that can read plastic cards embedded with either a barcode, magnetic strip, computer chip or another storage medium.
There are two types of smart cards: contact and contactless. Both have an embedded microprocessor and memory. The smart card differs from the proximity card in that the microchip in the proximity card has only one function: to provide the reader with the card's identification number. The processor on the smart card has an embedded operating system and can handle multiple applications such as a cash card, a pre-paid membership card, or an access control card.
If you've maxed out the memory on your camera, action cam, or smartphone, then there's a good chance you've invested in a memory card. Just one catch -- your laptop might not have a compatible port to speak with your memory card. That's where a card reader comes in. These handy go-between devices transmit data between a memory card and your computer. Let's answer some common questions about memory card readers.
Writing out your email has the added benefit of letting you rethink your situation and figure out what is the most important to you. Compiling your thoughts this way is a sort of self-therapy that you receive before you even get into the psychic reading. Another benefit to email psychic readings is that you are able to review the response you receive at any time, without having to miss any information that came in.   

Many Windows users come across the SD card reader not working error after the Windows 10 update and fail to get access to their important SD card data. It's a very nerve-wracking but also common issue that Windows 10 is stuck on the “SD card not recognized” problem. Don’t be worried. In this Windows 10 guide, we’ll walk you through top 4 ways to tackle this card reader not working issue.
If you've maxed out the memory on your camera, action cam, or smartphone, then there's a good chance you've invested in a memory card. Just one catch -- your laptop might not have a compatible port to speak with your memory card. That's where a card reader comes in. These handy go-between devices transmit data between a memory card and your computer. Let's answer some common questions about memory card readers.
Writing out your email has the added benefit of letting you rethink your situation and figure out what is the most important to you. Compiling your thoughts this way is a sort of self-therapy that you receive before you even get into the psychic reading. Another benefit to email psychic readings is that you are able to review the response you receive at any time, without having to miss any information that came in.  
Some people worry that a psychic reading performed on the phone will not be as thorough or accurate as a face-to-face reading. Thankfully, these fears are completely unfounded. Phone psychic readings are every bit as good as an in-person reading, as each advisor is rated anonymously following each call. This guarantees that you are contacting a qualified & professional psychic guide for each call.
If you are looking to speak with a psychic, PsychicCenter makes it easy to connect with an experienced spiritual guide. Plus, we have a special offer to allow new customers to see what our service has to offer at a significantly discounted rate. All new customers can receive their first 10-minute psychic reading from PsychicCenter for the special rate of only $5.

Getting psychic advice by phone also lets you enjoy your reading at your convenience as well as the privacy and comfort of your own home. They allow you to easily connect with an experienced psychic guide from anywhere no matter the time of day. Being able to hear the psychic's voice on the phone allows the reading to be just as powerful and impactful as it would have been if you were sitting across the table from each other.


A barcode is a series of alternating dark and light stripes that are read by an optical scanner. The organization and width of the lines is determined by the bar code protocol selected. There are many different protocols, such as the prevalent Code 39.[3] Sometimes the digits represented by the dark and light bars are also printed to allow people to read the number without an optical reader.
Many Windows users come across the SD card reader not working error after the Windows 10 update and fail to get access to their important SD card data. It's a very nerve-wracking but also common issue that Windows 10 is stuck on the “SD card not recognized” problem. Don’t be worried. In this Windows 10 guide, we’ll walk you through top 4 ways to tackle this card reader not working issue.
All biometric readers work similarly, by comparing the template stored in memory to the scan obtained during the process of identification. If there is a high enough degree of probability that the template in the memory is compatible with the live scan (the scan belongs to the authorized person), the ID number of that person is sent to a control panel. The control panel then checks the permission level of the user and determines whether access should be allowed. The communication between the reader and the control panel is usually transmitted using the industry standard Wiegand interface. The only exception is the intelligent biometric reader, which does not require any panels and directly controls all door hardware.
The advantage of using barcode technology is that it is cheap and easy to generate the credential and it can easily be applied to cards or other items. However the same affordability and simplicity makes the technology susceptible to fraud, because fake barcodes can also be created cheaply and easily, for example by photocopying real ones. One attempt to reduce fraud is to print the barcode using carbon-based ink, and then cover the bar code with a dark red overlay. The barcode can then be read with an optical reader tuned to the infrared spectrum, but can not easily be copied by a copy machine. This does not address the ease with which barcode numbers can be generated from a computer using almost any printer.