filter action
3.The action and demand of the anti alias filter in the system are recounted. After analyzing the switched capacitor IC-MAX290series filters,the anti alias filter is developed based on MAX293EPA. Espesially,the“resonance”phenomenon is analyzed theoretically and the analysis is proved by the experiment.
4.Because the diving water level is below 18.0m, the underground water in upper 15.0m water layer scatter everywhere and exist in format of upper backwater, the action of well pipe filter material is only the seep routeways of upper backwater, though the filter material, the underground water self-seep the precipitation well.
