How to put the student card into the card holder

Find a card holder suitable for the size of a student card.

If you want to put the student card into the card holder, you must first find a card holder suitable for the size of the student card. Some card holders are a little tight, so it is not easy to put student cards in. We can bend the student card slightly, so that it can be easily put into the card holder.

Meal cards can also be used with card holders. A meal card is usually an inductive IC card, which is a kind of radio frequency card. The basic principle of ic card is that the RF reader emits a set of electromagnetic waves with fixed frequency to the IC card, and there is an LC series resonant circuit in the card, the frequency of which is the same as that emitted by the reader. In this way, under the excitation of electromagnetic waves, the LC resonant circuit produces * * vibration, which makes the capacitor charged. At the other end of the capacitor, an electronic pump with unidirectional conduction 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, transmit data in the card or receive data from the card reader, and the electromagnetic wave is not interfered by the card sleeve, so the mika can be used with the card sleeve.