Basic principles of campus card work;
The RF reader sends a set of electromagnetic waves with fixed frequency to the ic card, and there is an IC series resonant circuit in the card, the frequency of which is the same as the frequency sent by the reader, so that under the excitation of electromagnetic waves, the LC resonant circuit generates * * * vibration, thus charging the capacitor; At the other end of this charge, a unidirectional electronic pump is connected to send the charge in the capacitor to another capacitor for storage. When the accumulated charge reaches 2V, this capacitor can be used as a power supply to provide working voltage for other circuits, send data in the card or receive data from the card reader.
The concept of one-card system:
The so-called "smart card" is a combination of smart card, automatic control, computer communication and network technology, so that people and tourists living in specific areas only need to carry a smart card with them. The card can be used not only as a work permit at work, but also as a parking voucher in parking lots, community clubs, company canteens and other places, which not only greatly facilitates the needs of users, but also improves the cumbersome phenomenon that users need to carry multiple cards on different occasions in the past.
Excellent features of the all-in-one card system: the contactless IC card consists of IC chip and inductive antenna, which is completely sealed in a standard PVC card and is not easily affected by external unfavorable factors. Read and write between contactless IC card and card reader by radio waves. Large storage capacity, fast transmission speed and long reading and writing life.
Contactless IC cards have the following excellent characteristics:
1. There is no mechanical contact between the contactless IC card and the card reader.
2. There are no exposed devices on the surface, which will not damage the IC card due to fouling and bending. The card itself is a passive component, small in size, durable and reliable.
3. The card reader does not need a card holder, and can be completely placed in the box.
4. There is no directionality when it is used, and the card can skim the surface of the reader from any direction to complete reading and writing.
5. Wireless communication between card reader and IC card.
6. The two-way password authentication system is realized by the card reader and IC card, which is verified by the three-level DES algorithm. The card reader recognizes the legitimacy of the IC card, and the IC card can recognize the card reader and the read-write permission of the card reader.
7. There are strict regulations on the issuance of contactless IC cards. Adopting the internationally recognized mifare standard, its card number is unique in the world. Secondly, part of the password is stored in the vehicle-mounted machine and the other part is put on the card to ensure the high confidentiality of the system.