Abstract: The present invention relates to an improved glow plug controller. The glow plug controller includes an analog temperature sensor, circuitry for converting an analog temperature signal to digital form, a microprocessor for analyzing temperature and other operating parameters and for controlling glow plugs and monitoring indicators in accordance with algorithms defined in the microprocessor. The temperature and control signals from the microprocessor are converted to analog form and applied to actuate glow plugs and indicators in accordance with determinations made by the microprocessor. A specific embodiment includes a manual override for facilitating operation even if the microprocessor should fail. A false temperature input is provided so that a false temperature representation can be directly applied to the microprocessor for factory and service center testing of microprocessor operation. Glow plug operation is controlled by way of a relay and multiple, independently fused glow plug circuits.

Abstract: A control circuit electrically coupled to the conductive coil of the elongated probe includes an energization circuit for coupling an alternating current signal to the coil. A monitoring circuit monitors a signal from the coil as the alternating current signal is applied to the coil that changes with a degree of overlap between the coupling member and the elongated probe and for providing an output signal related to the relative positions of two moveable members. A feedback control circuit adjusts the alternating current signal coupled to the coil to a control level based on the monitored signal from the monitoring circuit. Use of the feedback control enhances a dynamic range of the output signal from the monitoring circuit.

Abstract: Several embodiments of a rotational position sensor having a variable coupling transformer are disclosed. Each sensor employs at least one magnetically permeable transformer core and a primary and secondary coil. The primary coil in coupled to a time varying electrical signal and is mechanically coupled through a transmission to a rotatable shaft whose position is to be measured. As the shaft is rotationally displaced, the primary coil changes orientation thereby changing an output signal induced in the secondary. A detector is coupled to the secondary coil to monitor the output signal and correlate the signal to the shaft's rotational displacement.

Abstract: A gas density sensor having a prism in contact with a fluid whose density is determined. A light source shines light into the prism. The light is reflected off prism surfaces in contact with the fluid. As the fluid density changes, the amount of light reflecting off these surfaces changes depending upon fluid density. A detector placed to receive light reflecting off the surfaces determines density from sensed light.

Abstract: A magnetic motor is shown having magnetic members situated in relatively close proximity to each other; relative movement between the magnetic members is brought about by bringing the temperature of at least one of the magnetic members to the curie temperature thereof, and subsequent relative movement between the magnetic members is brought about by having the temperatures of all of the magnet members less than the curie temperatures thereof.

Abstract: An integrated circuit for driving a sensor includes an oscillator for providing a first clock signal synchronized to a periodic waveform supplied by an external source. A second clock signal in the form of a uni-polar square wave is derived from the first clock signal. A sinewave signal is generated by consecutively selecting voltage steps from a resistor ladder under control of the second clock signal. A low-pass filter removes from the sinewave signal higher frequency harmonics generated by switching through the steps of the resistor ladder. A linear amplifier utilizes an external capacitor to couple the filtered sinewave signal to the sensor. Temperature compensation is provided by comparing the voltage of the sinewave signal supplied to the sensor with an external temperature stable reference voltage. The integrated circuit also includes circuitry for amplitude demodulating a signal returned from the sensor to provide a sensor output signal.

Abstract: A multi-turn rotational position sensor. A spirally wound conductor has an inner end coupled to a rotatable shall through a transmission. As the shaft rotates, the spirally wound conductor changes shape. The spirally wound conductor is inductively coupled to a transfcrmer secondary and the transformer coupling between the spirally wound conductor changes as the shaft rotates. An output from the transformer secondary is used to determine the shaft's rotational position.

Abstract: A position sensing device including two spaced conductive coils constituting a primary and secondary winding of a transformer. A coupling member is mounted to a moveable object such as an automobile steering mechanism and moves relative the primary and secondary windings. This movement adjusts or alters the transformer coupling between the primary and the secondary and produces a variable output signal which can be correlated through use of appropriate circuitry to the position of the moveable member. Two alternate designs are disclosed. In a first design, the transformer primary and secondary are disposed side-by-side and the coupling member slips over the primary and secondary for relative linear movement. In a second design, the primary and secondary are disposed one within the other and the coupling member fits within a gap between the primary and secondary.

Abstract: A fuel sensing and monitoring apparatus and method is disclosed. The apparatus includes two spaced conductive coils constituting a primary and secondary winding of a transformer. A short coupling member is mounted to a movable member to which a float is attached, the float being located in the fuel tank of a vehicle. The float and movable member move in response to a change in fuel level in the tank. When the fuel level changes, the short coupling member moves relative to the primary and secondary windings. This movement adjusts or alters the transformer coupling between the primary and secondary and produces a variable output signal which can be correlated, through the use of appropriate circuitry, to a representation of the level or fuel in the tank as indicated by the position of the movable member to which the float is attached.

Abstract: A position sensing device including two spaced conductive coils constituting a primary and secondary winding of a transformer. A coupling member is mounted to a moveable object such as an automobile steering mechanism and moves relative the primary and secondary windings. This movement adjusts or alters the transformer coupling between the primary and the secondary and produces a variable output signal which can be correlated through use of appropriate circuitry to the position of the moveable member. Two alternate designs are disclosed. In a first design, the transformer primary and secondary are disposed side-by-side and the coupling member slips over the primary and secondary for relative linear movement. In a second design, the primary and secondary are disposed one within the other and the coupling member fits within a gap between the primary and secondary.