Development Of Lithium Self-discharge Rate Of Detection And Sorting Equipment

Given that local action rate is one of the main parameters to evaluate the performance of lithium cell, this dissertation introduces the equipment of the lithium cell local action rate measurement and selection based on the idea of embedded system. The phenomenon that the voltage of lithium cell declines after being placed for some time is called local action of cell. The local action rate is the ratio of voltage drop and the total voltage of cell. Consisting of measuring and filtering subsystems, lithium cell voltage measuring and filtering device measures the voltage of cell and filters the unqualified cell.This dissertation focuses on the hardware and software design of lithium cell voltage measuring and filtering device. The subsystem implementing the measurement of cell is called the measuring apparatus and the one implementing the selection function is called filtering apparatus. They can implement their own tasks independently and can exchange data through host computer to achieve the task of filtering the unqualified cells. Considering the full expandability, the equipment adopts modularized design. The measuring and filtering apparatuses have the same CPU board including the network port, serial port, external RAM and FLASH. An additional CPLD is added for further function expansion.The host PC and terminal machine communicate with each other by UDP, and the reading of IC card is through serial port. The measuring apparatus consists of analog switch, AD converter ADS1256 circuits while the filtering apparatus is composed of latch 74HC374. The 32 bits CPU S23410B based on ARM is adopted. The software developing platform of terminal machines is Tornado 2.2 of WindRiver Company. The software development is elaborated and the software modules are illustrated in this dissertation to make the function of the equipment easily understandable.The equipment is the quality-check apparatus manufactured specifically for cell production enterprises and can be also used for research and experiment on the performance of cells.