The implement of multichannel and adjustable gain A/D sampling system

As the serve life of a battery will be greatly shorten if it is often over charged, battery automatic testing system can be used to judge the quality and the end point of battery charging process. One kind of multichannel and adjustable gain A/D sampling systems is introduced in this paper. In this system, 8-channel analog multiplexers/demultiplexers CD4051 and instrumentation amplifier INA114 are used to get adjustable gains, another CD4051 is used as digitally-controlled analog switches to expand channels of A/D sampling system. This circuit can replace relay selective switcher circuit in traditional intelligent instruments. It has the advantages of small turn on resistance and large shut down resistance.