Abstract: A computer control device which provides spacial information to a computer or electronic game by sensing the linear acceleration or tilt angle of the control device. The computer control device includes an accelerometer having an enclosure containing a fluid and temperature sensing elements positioned within the enclosure. The fluid moves across the temperature sensing elements in free convection during acceleration or inclination of the enclosure causing a temperature differential between the temperature sensing elements which is measurable. The control device incorporating one or more of these accelerometers senses acceleration or tilt in one to three dimensions and may be used to control a cursor on a computer screen, a display of a virtual reality device, or other computer and electronic game displays.

Abstract: A convective accelerometer and inclinometer includes two temperature sensing elements mounted within a sealed enclosure containing a gas. The application of heat to the gas within the enclosure by a heating element causes the gas to flow in a predetermined pattern in free convection. When linear acceleration or inclination is applied to the enclosure the convective flow of gas is affected causing a temperature differential between the temperature sensing elements. This temperature differential is measured as a difference in electrical resistance between the two temperature sensing elements which is proportional to the acceleration. The device can be used to measure linear acceleration, velocity, position or inclination. The device can also be used as an inclinometer for measuring the angle of gravity. The device has a wide variety applications particularly within the automotive field.

Abstract: An apparatus (102) is adapted to detect the linear extension (position), velocity and acceleration of a hydraulic cylinder (108). The hydraulic cylinder (108) defines a variable length coaxial resonant cavity (112). Under the control of a controller (228), an RF transmitting section (114) and an RF receiving section (116) are used to determine the resonant frequency of the cavity. The resonant frequency of the cavity (112) is determined by comparing a received signal with a threshold and detecting slope intercept conditions.

Abstract: An apparatus (102) is for detecting the linear extension (position), velocity and acceleration of a hydraulic cylinder (108). The hydraulic cylinder (108) defines a variable length coaxial resonant cavity (112). Under the control of a controller (228), an RF transmitting section (114) and an RF receiving section (116) are used to determine the resonant frequency of the cavity. The resonant frequency of the cavity (112) is determined by comparing a received signal with a threshold and detecting slope intercept conditions.

Abstract: An apparatus (102) is adapted to detect the linear extension (position), velocity and acceleration of a hydraulic cylinder (108). The hydraulic cylinder (108) defines a variable length coaxial resonant cavity (112). Under the control of a controller (228), an RF transmitting section (114) and an RF receiving section (116) are used to determine the resonant frequency of the cavity. The resonant frequency of the cavity (112) is determined by comparing a received signal with a threshold and detecting slope intercept conditions.

Abstract: An apparatus is adapted to detect the linear extension, velocity and acceleration of a hydraulic cylinder. The hydraulic cylinder defines a variable length coaxial resonant cavity Under the control of a controller, an RF transmitting section and an RF receiving section are used to determine the resonant frequency of the cavity. The receiving section includes a comparator circuit for increasing the sensor's sensitivity and eliminating spurious detections of the cylinder's resonant frequency. The linear extension of the cylinder is determined as a function of the resonant frequency.

Abstract: An apparatus is adapted to detect the linear extension, velocity and acceleration of a hydraulic cylinder. The hydraulic cylinder defines a variable length coaxial resonant cavity. Under the control of a controller, an RF transmitting section and an RF receiving section are used to determine the resonant frequency of the cavity. The receiving section includes an equalizer circuit for compensating for the insertion losses of the hydraulic cylinder. The linear extension of the cylinder is determined as a function of the resonant frequency.

Abstract: A constant bias voltage and current for a transistor is provided by two series resistors connected across the transistor with a voltage regulator connected to a source of DC voltage for maintaining a predetermined voltage across the one resistor connected to the output electrode (drain or collector) of the transistor. The common electrode (source or emitter) is connected to a source of constant current.

Abstract: A communication system for the transfer of information between a central station and an addressed point has the points organized in decimal groups at different remote stations, and selects a point for communication after enabling the group thereof with a unique station address. The central station equipment produces multiple-level addressing signals in serial sequence appropriate for transmission on a pair of conductors with other signals having a different frequency characteristic. All remote stations can be coupled in common with the central station, but the many points are normally inactive with regard to communication with the central station. An addressed remote station activates a selected point therein for transferring information with the central station.