Compared with the traditional IC card, the biggest advantage is that it does not need contact, which reduces many contact problems and has high reliability.
As for related technologies, please search: contactless IC card, or RFID technology.
Data: bus IC card (integrated circuit card) is contactless. That is to say, as long as the IC card is within a certain distance of the card reader, the card reader can read the data in the card without physical contact between the IC card chip and the card reader.
Introduction of contactless ic card contactless IC card, also known as radio frequency card, successfully solves the problems of passivity (no power supply in the card) and contactless, and is a major breakthrough in the field of electronic equipment. It is mainly used in automatic toll collection systems of buses, ferries and subways, as well as access control management, identity authentication, electronic wallets and so on.
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Principle of ic card: The basic principle of ic card is that 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, which makes the LC resonant circuit vibrate under the excitation of electromagnetic waves and charge 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.
I don't see a clear statement about the information storage of IC cards, but I think the relevant information is stored inside IC cards. In my opinion, the current IC card reader is not connected to the data center in real time, otherwise the workload of this wireless network is too large and the information must be stored on the card.