Pressure transducer for musical instrument control

Abstract

A pressure-to-conductance transducer, which avoids dependency on pressure-sensitive properties of particulate materials which may be difficult to formulate in stable form, utilizes instead the principle of translating applied pressure into variation of area and region of contact between a resistively coated Mylar tape element and a pair of adjacent contact plates, connected to controlled circuitry via a cable. In an embodiment for foot control of musical effects, a base mounts the contact plates and a surrounding separable Velcro gasket supporting a semi-rigid pressure sensor plate holding the resistive element closely spaced above the contact plates. A void in the element spans the gap between the contact plates. The conductance value appearing between the contact plates varies with the pressure applied to the sensor plate, ranging from low conductance with light offset pressure to high conductance with heavy overall pressure. Easy internal access and inexpensive materials, particularly the resistive element which may be made from two inch audio recording tape, greatly facilitate maintenance and replacement, and enable easy response tailoring by shaping the resistive element void.