Abstract: An analog encoder of one embodiment of the invention is disclosed that includes an input mechanism, a digital signal processing mechanism, and an output mechanism. The input mechanism is to receive and digitize different analog encoder signals. The digital signal processing mechanism is to generate inverse analog encoder signals from the different analog encoder signals, and to apply dynamically changeable gain and offset corrections in real-time. The output mechanism is to generate digital quadrature signals from crossing points among the analog encoder signals and the inverse analog encoder signals, and a position value based on a direction of the digital quadrature signals for external access.

Abstract: An analog encoder of one embodiment of the invention is disclosed that includes an input mechanism, a digital signal processing mechanism, and an output mechanism. The input mechanism is to receive and digitize different analog encoder signals. The digital signal processing mechanism is to generate inverse analog encoder signals from the different analog encoder signals, and to apply dynamically changeable gain and offset corrections in real-time. The output mechanism is to generate digital quadrature signals from crossing points among the analog encoder signals and the inverse analog encoder signals, and a position value based on a direction of the digital quadrature signals for external access.

Abstract: An encoder includes a housing, a light source coupled to the housing, and a light sensor coupled to the housing and positioned to receive a light beam from the light source. The encoder also includes a wheel having opaque and transmissive sections which may be positioned to pass through the light beam before it reaches the light sensor. The encoder further includes a floating aperture piece, which defines at least one aperture. The aperture is positioned so that the light beam must pass through it before reaching the light sensor. The floating aperture piece slidably engages the housing while allowing a loose tolerance between a position of the wheel and a position of the housing, thereby substantially eliminating a positioning error between the aperture and the wheel.

Abstract: Techniques for improving the robustness of an optical encoder are described. The escoder has an array of photosensitive elements, which respond to light reflected from or transmitted through a pattern of lines formed on a code wheel or strip. The photosensitive element comprising the array are arranged in dispersed, non-contiguous detector areas.

Abstract: An encoder includes a housing, a light source coupled to the housing, and a light sensor coupled to the housing and positioned to receive a light beam from the light source. The encoder also includes a wheel having opaque and transmissive sections which may be positioned to pass through the light beam before it reaches the light sensor. The encoder further includes a floating aperture piece, which defines at least one aperture. The aperture is positioned so that the light beam must pass through it before reaching the light sensor. The floating aperture piece slidably engages the housing while allowing a loose tolerance between a position of the wheel and a position of the housing, thereby substantially eliminating a positioning error between the aperture and the wheel.

Abstract: An encoder includes a housing, a light source coupled to the housing, and a light sensor coupled to the housing and positioned to receive a light beam from the light source. The encoder also includes a wheel having opaque and transmissive sections which may be positioned to pass through the light beam before it reaches the light sensor. The encoder further includes a floating aperture piece, which defines at least one aperture. The aperture is positioned so that the light beam must pass through it before reaching the light sensor. The floating aperture piece slidably engages the housing while allowing a loose tolerance between a position of the wheel and a position of the housing, thereby substantially eliminating a positioning error between the aperture and the wheel.

Abstract: A reciprocating piston pump provides pulseless delivery of liquid. It is suitable for use in compact environments or for the delivery of small amounts of liquid, as in chromatographic analysis devices. The pump includes two pistons with pumping chambers that are alternately connected to inflow and outflow lines through a control valve. The control valve moves between a first position in which inflow is directed to the first piston chamber and outflow to the second piston chamber, and a second position in which outflow is directed to the first piston chamber and inflow is directed to the second piston chamber. Each outflow pulse from the piston is sustained longer than each inflow pulse, and the outflow pulses are staggered and partially superimposed to provide substantially pulseless delivery of liquid from the pump. A rotating cam moves the pistons of the pumps and the control valve between their operating positions described above.

Abstract: A low inductance probe contains a signal probe shaft having a signal probe point and an adjacent ground conductor or conductive shield for placing on the circuit location which is desired to be measured, a ground probe arm having a ground probe point for placing on a convenient ground location. The ground probe arm is attached to the signal probe shaft by means of a hinge which enable the ground probe arm to rotate between zero and approximately 135 degrees in a compass like fashion. The ground conductor of the signal probe shaft and the ground probe point of the ground probe arm are electrically connected by means of a low inductance ground lead consisting of a monolithic, flexible strand of conductive foil.

Abstract: A low inductance ground lead for grounding a signal probe used in high frequency measurement to a ground probe. A ground lead comprises a single flexible strand or multiple strands which are substantially untwisted with respect to one another. Preferably, the strands have a rectangular cross-section and a relatively large surface area for a given cross-sectional area. Substantially noninductive connections for connecting one end of said ground lead to the signal probe and the other end of said ground lead to the ground probe are provided, so as to bypass the self-inductance of the signal probe and the ground probe.