Abstract
This paper presents a design method of a pneumatic transmission filter with a low-pass characteristic. The principle of the design method is based on the theory of syntesis on electrical passive networks. The elements forming pneumatic filters are loss-less unit lengths of parallel capillaries and volumes, and the mutually cascade connection of these elements realizes a pneumatic ladder network with a desired low-pass characteristic.
By the method mentioned above, some filters are manufactured, and these characteristics are experimentally examined. A summary of the results of these examinations is shown below.
1) All of the filters have a good low-pass characteristic, but in comparing it with a desired characteristic, the characteristic distortion appears in the neighbourhood of a cut-off frequency.
2) The magnitude of the distortion increases as the order of the approximating function increases.
3) It is pointed out from a theoretical analysis that the distortion may be caused by loss components in unit lengths of parallel capillaries.
