Abstract: A system including a method and means for trimming capacitive-type remotely-located fuel probes that eliminates the previously-used variable trim capacitor and substitutes a rugged, inexpensive, standard-value signature resistor connected between the AC input and ground to provide "calibration offset" data needed by the fuel measurement electronics to make a determination of actual probe capacitance. The system may be applied to any such probe having a blocking capacitor in series with the probe capacitor, which blocking capacitor insures accurate measurement of the signature resistor when the leakage resistance is significant. When applied to DC or AC FHC probes, the C.sub.fhc capacitor is replaced with a non-critical DC-blocking capacitor, that is typically at least 100 times greater in capacitance value than the C.sub.

Abstract: A fuel gauging system for use in determining the level of fuel in a tank. The system incorporates a resonant circuit for measuring the resonant frequency of at least one probe immersed in the fuel located in the tank. From measurements of variations of the frequency of resonance, the level of liquid in the tank is determined, and the fuel quantity is then calculated and displayed.

Abstract: A system and method for processing analog XYZ calligraphic video signals for presentation as a stroke image on a flat panel LCD raster display screen by converting such signals in coordinated sets to digital data in a stroke frame buffer memory. The X and Y signals define column and row addresses in memory for storage of the coordinated Z digital color brightness data, which addresses correspond to pixel locations on the surface of the display screen to which the data is transferred to form the stroke image. By storing fractional bits from the X and Y digital data in the buffer memory along with the coordinated color intensity data a high resolution stroke image can be formed using a conventional sized buffer memory. Further, noise and clock conversion artifacts are minimized by saving the first point of each stroke line or vector and by using the X and Y fractional bits for beam shaping utilizing anti-aliasing discs.

Abstract: A system for sensing metallic debris in fluid flow, including an inductive probe utilizing one or more capacitors with a single turn resonant coil disposed about the flow passageway wherein a second, co-linear, multiple turn coil is provided about the passageway and loosely coupled via mutual inductance to the resonant coil such that the two windings produce a step-up transformer with increased impedance to closely match the impedance of the electrical output cable. This impedance matching reduces output signal loss permitting the sensitive components of the system to be remotely located from the usually hostile environment of the probe. Additionally, a toroid element of low loss, low reluctance material is disposed between the probe and its conductive housing to provide a guiding path for the magnetic "lines of force" of the sensing field produced by the probe, to avoid losses in the housing.

Abstract: An apparatus is provided for controlling the luminous output of a fluorescent lamp over a wide dimming range. The luminous output is controlled by controlling the lamp current, while the lamp is immersed in a lateral electrostatic field. The lamp and external electrostatic ionization electrodes are driven by a true analog voltage-to-current converter that has a dynamic range inherently wider than conventional PWM circuits. A modified, transformer coupled, push-pull converter with an analog-current-driven primary circuit is used in one embodiment of the apparatus. The lamp driver must be capable of providing a high compliance voltage consistent with the I-V profile of the lamp. A subordinate primary winding on the transformer may be used to reduce magnetization current and to supply sufficient energy for supporting the lateral electrostatic field that is generated by the ionization electrodes which may be printed on a PWB mounted behind the lamp.

Abstract: An inductive debris monitor for detecting chip-particles in tubing of a fluid wetted system. The inductive debris monitor includes a multi-turn detector and an electronic circuit having a resistor bridge configuration. The multi-turn probe detector wraps around the tubing of a fluid wetted system a plurality of times to detect the presence of the chip-particles while the electronic circuit analyzes and deciphers the detected chip-particle information.

Abstract: A stabilization biasing circuit is provided for an avalanche photodiode. The stabilization biasing circuit allows for a wide range of light levels to be inputted to the avalanche photodiode, while the avalanche photodiode operates under extreme temperatures. The stabilization biasing circuit also provides for an automatic gain control, thereby enabling the electrical output signal of an avalanche photodiode to be relatively constant over a large range of inputted light levels and temperatures. Absence of optical input is identified as an increase in diode noise due to avalanche breakdown.

Abstract: A voltage-controlled oscillator capable of very high ratios of modulation to oscillation frequency is disclosed embodying a resonant circuit with an inductance and two tuning diodes connected with opposite polarity in series across the inductance, a cross-coupled feedback amplifier circuit with two matched MMIC inverting amplifiers capacitively cross-coupled to the resonant circuit for driving the resonant circuit into oscillation at its resonant frequency to produce an output carrier wave, and a transmission line resonator connected to the resonant circuit between the tuning diodes to couple a wide band frequency modulating voltage thereto for modulating the output carrier wave.

Abstract: An apparatus is provided for mating and unmating electronic equipment to a rack in an associated electrical or electromechanical system. The apparatus is further operative to hold the electronic equipment in a mated condition to prevent separation during severe vibration or shock. The apparatus includes an actuator for moving a plurality of latches which engage hold-down brackets on the electronic equipment. The engagement of the latches on the apparatus and the hold-down brackets enables insertion, withdrawal and holding down of the electronic equipment in the rack. A clutch assembly is provided to prevent over-insertion of the electronic equipment into the rack.

Abstract: A triad sensor apparatus (300) comprises a passive ring Sagnac interferometric arrangement having a light source circuit (308) and a series of three multi-turn fiber optic rings (302, 304, 306). An optics/modulator circuit (312) is adapted to selectively switch optical waves emitted from the light source circuit (308) and transmit the signals through the corresponding fiber optic rings as counterpropagating optical waves. Nonreciprocal phase modulation is applied to the counter-propagating waves, and the waves are recombined so as to produce a "zero order" fringe pattern having an intensity varying in accordance with the relative phase between the counterpropagating waves. Optical waves from the light source circuit (308) are selectively applied to a ring path during a given time period, while the photodetector circuit (324) is detecting light waves which have emerged from another ring path during the same given time period.

Abstract: A drive wheel for rotating a workpiece while the latter is in contact with a grinding wheel during a grinding operation. The drive wheel is in the form of a pneumatic tire with a tire valve which permits easy variation of the internal pressure in the drive wheel. Thus the relative softness or hardness of the drive wheel can be changed in accordance with requirements attendant to the grinding operation. The drive wheel is motor-driven and a speed control device operates to slow the motor drive shaft when high torque loads are applied to the drive wheel by the workpiece, during heavy cutting of the workpiece by the grinding wheel. Thus the workpiece rotates slowly during heavy cutting and faster during light cutting.