Abstract: A two-axis tilt sensor, or inclinometer (10), uses a spherical reference element (18) floating in an inert fluid (20) and including a magnet (42) to produce an asymmetrical weight distribution. The asymmetrical weight distribution maintains the spherical reference element at a constant orientation with respect to gravity, while the position of the magnet on the spherical reference element with respect to a housing (12) is detected by opposing pairs of Hall effect sensors (22) mounted on the housing. The outputs from opposing pairs of sensors are processed by differential amplifier circuits (80) to determine signals corresponding to the tilt of the inclinometer about the axes.

Abstract: A pressure transducer includes a base ply, a resistance ply disposed on the base ply and at least two spaced apart contacts juxtaposed in relation to the resistance ply whereby at least one of the contacts may be pressed against the surface of the resistance ply. The resistance ply is made by spraying or silk screening a mixture of resin resistive to electrical conduction and a conductive particulate and then curing the composition to form a thin resistance ply having a surface with a multiplicity of micro-protrusions formed by the conductive particulate. The ratio of conductive particulate to resin is such that the mean distance between microprotrusions is greater than about five time the size of the conductive particles. The particles are in the range of about 0.5 to 10 microns and the resin layer is about is 0.4 to 0.8 microns thick.

Abstract: A pressure transducer includes a base ply, a resistance ply disposed on the base ply and at least two spaced apart conductors juxtaposed in relation to the resistance ply whereby at least one of the conductors may be pressed against the resistance ply. The resistance ply is made by spraying or silk screening a mixture of a continuous matrix conductive resin and a stannous oxide particulate and then curing the composition to form a solid resistance ply having a surface with a multiplicity of micro-protrusions formed by the stannous oxide particulate.

Abstract: A digitizer pad apparatus includes at least one digitizer ply where each digitizer ply has a first and a second resistor strip, each with a resistance gradient along its length, oriented in spaced apart relationship. A plurality of conductor traces are interconnected along the length of each resistor strip to extend toward and be interleaved between each other to define a sensor pad region. Each sensor pad region defines a dimensional direction. A shunt ply is positioned to face the sensor pad region in normally non-conducting relationship so that when a selected area is pressed into contact with the conductor traces, conduction between adjacent conductor traces via the shunt ply will occur in the selected contact area. The selected contact area has a first edge and a second edge opposite the first edge along the defined dimensional direction.

Abstract: A digitizer pad includes at least two base plys, each having thereon at least three terminals, a resistor ply disposed between two of the terminals with a plurality of conductors extending from each resistor ply which are spaced apart and interleaved with a plurality of conductors extending from each third terminal. The respective base plys' conducting surfaces face each other and are sandwiched about a nonconductive ply that includes a pressure sensitive conductive layer on each side, the area of which layer covers a portion of the area encompassed by the interleaved conductors on each base ply. The resistor plys and conductors on each base ply are at predetermined angles to those on the base ply, hence the conductors of each base ply form two predefined axes. A voltage source is sequentially coupled, by suitable switching means, across a selected pair of terminals on each ply to measure the selected location along the parameter dimension defined by the terminals across which the voltage source is coupled.

Abstract: A digitizer pad includes at least two sets of terminals where each set has at least a first and second terminal positioned to define a parameter dimension therebetween. A resistor ply is disposed between the terminals of each set. The resistor ply has an electrical contact surface with a resistance gradient profile between the terminals in each set. An output terminal is electrically interconnected to a selected location along the contact surface of the resistor ply. A voltage source is sequentially coupled, by suitable switching means, across a selected subset of terminals in each set of terminals whereby the voltage at the output terminal is a measure of the selected location along the parameter dimension defined by the terminals across which the voltage source is coupled.