说明：  EM卡的一些资料 读卡电路产生125KHZ并驱动感应线圈向幅射电磁波，当ID卡读卡天线的磁场范围内时，卡内的线圈接收电磁波的能量，卡内的电路对其整流、稳压后作为卡片系统工作电压，并从接收到的振幅调制脉冲调制出信息并送到内部控制逻辑，并将内部数据经由天线送出，读卡电路通过整形,放大,把收到的曼码送到单片机中进行解码。
(EM card reader some information arising from 125KHz circuit and induction coil drive to the radiation of electromagnetic waves, when the ID card readers magnetic field range of the antenna, the card inside the receiver coil electromagnetic energy of the circuit card of its rectifier, regulator After the card system as the operating voltage, and from the received pulse modulation amplitude modulation and the information sent to the internal control logic, internal data will be sent via the antenna, circuit card reader through the shaping, amplification, the received code to a single man decode chip machine.)