Abstract: An FM stereo receiving system and a method for aligning phases of RF signals received by multiple antennas. The FM stereo receiving system includes two antennas for receiving RF signals having a common frequency but potentially different phases. The system also includes an FM receiver having a detector output and a pilot output on which a pilot tone, such as a 19 kHz pilot tone, is present. A summer is included in the system for summing the RF signals and providing the summed signal to the receiver. The amplitude modulator of the system resides between one of the antennas and the summer to amplitude modulate the antenna's RF signal at a perturbation frequency which is a whole number multiple greater than 1 of the pilot tone. The receiver thus produces on its phase detector output a phase signal having a frequency equal to the perturbation frequency and a magnitude corresponding to the phase error between the RF signals which is connected in a feedback loop to align the phases.

Abstract: An adaptive electronic climate control (ECC) system for a vehicle that allows adjustments to the temperature setting and blower speed controls of the ECC system to teach the system to automatically be set to the vehicle operator's comfort level. If the vehicle operator adjusts the temperature set point at a particular ambient air temperature, the system will store this change for that ambient air temperature. Once the change has been validated, the next time the system encounters that ambient air temperature, the system will automatically provide the appropriate air mixture as previously set by the vehicle operator. Further, when the vehicle operator adjusts the blower speed, the system will gradually adapt the blower speed to that which is set by the vehicle operator for a particular set of vehicle parameters that affect the climate within the vehicle.

Abstract: A backlit component which is suitable for use in an illuminated graphic keypad in an instrument panel of an automobile The backlit component is adapted to be illuminated by a light source located beneath the keypad, but off to one side of the backlit component in order to accommodate an actuator member extending from the backlit component and an electrical switch actuated by the actuator member when the backlit component is pressed. The backlit component is formed from an optically conductive material to enable light emitted by the light source to be transmitted through the component to an insignia formed on the exposed or exterior surface of the component. The backlighting intensity of the backlit component is enhanced by forming the actuator member from an optically conductive material, and equipping the actuator member with a reflective surface such that light emitted from the light source is reflected toward the insignia.

Abstract: A digital control device and method are provided for controlling functions such as volume and tuning for an electronic radio in response to a digital rotary switch. The apparatus includes a digital switch movable to a plurality of positions and which has a plurality of digital outputs to represent the positions. Control increments corresponding to an amount of rotation and rate of rotation of the switch are stored in a memory. The rotary switch output is periodically sampled to determine when switch movement occurs and to further determine the direction of switch rotation based on a sequence of the plurality of digital outputs. The rate of rotation of the rotary switch is then determined from counting changes in position of the switch over a sampling time A control increment is looked up in the memory that corresponds to the determined rate. The control increment is then used to change a digital output signal for controlling the electronic device.

Abstract: A low inductance triaxial semiconductor switching module. The module permits high power semiconductor switching devices to operated at high frequency but with low inductance. The module incorporates compositional, geometrical and electrical symmetry in connection with a triaxial terminal subassembly having coplanar contact areas. The terminal subassembly is readily fabricated and assembled into the module. The module also includes short internal leads, a special circumferential array of substrates subassemblies, and a circular circuit board having gate and Kelvin circuit patterns.

Abstract: A vehicle has a real time suspension control which requires, as inputs, a set of absolute body modal velocity signals. Accurate estimates of these signals are derived from relative position sensors at the body suspension points by converting the relative vertical position signals from these sensors to relative body modal (e.g. heave, pitch and roll) velocity signals and passing each of these signals through a second order low pass filter including an additional phase inversion for compensation of the 180 degree filter phase lag. Thus, the necessity of absolute body accelerometers is eliminated, for a significant cost reduction. In a vehicle having significant front to rear flexing or flexing within the front or rear suspension that can affect the accuracy of the estimated absolute body roll velocity, the normal roll velocity transformation equation is modified to include only the front or the rear pair of relative velocity signals.

Abstract: Conformal coating materials are provided for forming a protective conformal coating on the surface of an electronic assembly. The conformal coating materials are characterized by being hot melt materials, in that they are each initially a solid or semisolid at approximately room temperature, a liquid at an elevated temperature at which the coating material is applied to the electronic assembly, and solidify upon cooling to a temperature corresponding to a service temperature of the electronic assembly. As such, the coating systems can be rapidly applied through various highly controllable techniques associated with hot melt dispensing equipment. In addition, the coating systems quickly solidify upon cooling to allow handling of the electronic assembly. The conformal coating systems may be nonreactive, indicating that the system can be remelted, or reactive, indicating that a post-application curing process occurs over time at a temperature less than the elevated application temperature.

Abstract: A plurality of optical projectors focus telltale messages, one at a time, onto a vehicle instrument panel display area. In one embodiment a logic circuit assigns priority to the messages and displays only the message of higher priority when more than one message is prompted. The projection lamps are high intensity LEDs arranged in parallel but having diodes in series with lower priority lamps to hold them off when a higher priority lamp is energized. A constant current source regulates the LED current. In another embodiment two message lamps are controlled by a logic circuit such that when both are prompted for display an oscillator causes the messages to be displayed alternately, but when either message alone is prompted, its lamp will be energized continuously.

Abstract: A conversion circuit is provided for converting a differential voltage to a single-ended voltage. The conversion circuit has an input circuit including first and second input lines for receiving a differential voltage that is produced by a magnetic sensor in response to rotation of a wheel. First and second buffers are coupled to the first and second input lines, respectively, of the input circuit and each provide a buffered output. The conversion circuit further includes a difference amplifier having a positive input coupled to the output of the first buffer and a negative input coupled to the output of the second buffer. The amplifier provides as an output the voltage difference between the first and second inputs as a single-ended voltage output. The output circuit further converts the single-ended voltage output into a series of voltage pulses which provide rotational speed information about the wheel.

Abstract: Low residue water-based soldering flux, and process and system for using the same. The flux includes a mixture of succinic, glutaric and adipic acid in water, and optionally a wetting agent. The flux is applied to a surface to be soldered. The flux is dried. The surface is soldered. The flux is applied at an application station, dried at a drying station and soldered at a soldering station.

Abstract: A sensor interface circuit is provided which realizes common mode rejection and achieves a desired transfer response while realizing a simplified amplifier arrangement. The interface circuit is particularly useful for amplifying and conditioning signals generated by an oxygen sensor on an automotive vehicle. The sensor interface circuit has first and second inputs for receiving input voltages from a sensor which are joined together to provide a differential voltage representative of the voltage potential between the first and second inputs. One input may receive a common mode ground employed by the sensor. An amplifier having a first input receives a differential voltage at an inverting input and a positive non-zero reference voltage at a non-inverting input. The amplifier has an output coupled to a grounded switch for providing an output signal referenced to reference ground.

Abstract: Apparatus for producing a light mask for balancing light across a display area of a vehicle instrument cluster comprises a camera, a digitiser and a computer. An image of the display area is obtained and digitized to produce data relating to the illumination levels of the image at a plurality of pixels. The illumination levels are used to calculate an appropriate light mask for the display area on the basis of the transmissive density of the masking ink used and of a reference illumination value relating to the least lit part of the display area which it is desired to illuminate. The light mask comprises an array of dots having a diameter related to the amount of attenuation required in the area in which the dot is located. Up to three masking layers may be provided if a single layer is insufficient to produce the required attenuation with the chosen masking ink. Balanced coverlays can readily be produced, and the number of masking layers required can also be reduced.

Abstract: In accordance with the teachings of the present invention, a fault detection circuit is provided which detects short circuits on differential leads associated with a magnetic sensor and modifies said differential voltage to avoid possible errors associated with a short circuit. The circuit includes a first and second input coupled to first and second signal lines for receiving a differential voltage. A first voltage comparator compares voltage potentials at the first and second signal lines so as to detect equal voltage crossings and provide an output in response thereto. A rectifier is coupled to the first and second signal lines in the output of the first comparator and has first and second outputs for producing positive half-wave voltage cycles with a voltage potential at each of the first and second lead lines. A second comparator is provided for comparing the half-wave voltage cycles with a first threshold voltage that represents a short circuit power source.

Abstract: A booster power converter particularly suited for an automobile and having a compensation network that responds to a sudden negative input voltage excursion. The booster power converter responds to the negative input excursion by preventing its boosted output from falling below a predetermined voltage level so that voltage regulators, normally connected to the output stage of the booster power converter, are not distrupted in performing their desired regulation. The compensation network, upon sensing a decrease of the booster voltage below a predetermined lower limit, generates a control signal which causes the booster power converter to seek and obtain a maximum duty cycle operation. Upon sensing an increase of the booster voltage above a predetermined upper limit, the compensation network removes the control signal causing the booster power converter to cease operation at its maximum duty cycle, and return to its normal duty cycle of operation.

Abstract: A terminal pattern is provided for an integrated circuit device, such as a ball grid array package or an integrated circuit flip chip. The terminal pattern is composed of a number of terminals arranged in concentric arrays, each array having a substantially circular shape and being composed of a number of terminals. The terminal pattern is composed of at least two arrays, and more typically three or more arrays. When the integrated circuit device is mounted to its intended substrate, the individual terminals of the terminal pattern each register with and are soldered to a corresponding conductor of a conductor pattern formed on the substrate. A significant advantage is that, due to the terminals of the terminal pattern being arranged in concentric arrays, a smaller maximum width for the terminal pattern is achieved than possible with a conventional rectangular terminal pattern having the same number of terminals.

Abstract: A rotary encoder capable of detecting angular rotation of a rotating shaft, and identifying its neutral position without the need for multiple encoder wheels. A magnetoresistive sensor is positioned adjacent the periphery of a single multipole magnet ring attached to a steering wheel shaft. The magnet ring comprises alternating N-pole and S-pole magnetic regions along its periphery, the surface of one of the regions containing a demagnetized portion. The sensor produces a sinusoidal signal as the shaft is rotated, responsive to the passage of the magnetic regions, with a period equal to the passage of two successive magnetic regions adjacent the sensor. The angular position of the shaft which aligns the demagnetized portion adjacent the sensor corresponds to the shaft's neutral position. Aligning of the demagnetized portion adjacent the sensor causes a voltage irregularity within the sensor's otherwise sinusoidal output signal, which is detected by a signal processing circuit.

Abstract: A low-input capacitance self-biased CMOS buffer amplifier (10) which buffers a low-amplitude capacitively coupled output of a sensor to subsequent output circuitry. The buffer amplifier (10) includes a buffer stage (12) which includes an input FET (16) whose gate terminal is connected to the output of the sensor. In order to eliminate the gate-to-source, gate-to-drain and gate-to-substrate capacitances of the input FET (16), various FETs are associated with the buffer stage (12) are interconnected such that the integrity of the input signal is maintained. An output FET (18) has its source terminal connected to the source terminal of the input FET (16). Additionally, a tail cascoded current source (20, 22) is connected to the source terminals of the input and output FETs (16, 18) such that the gate-to-source voltages of these two FETs (16, 18) is the same. The gate terminal and the drain terminal of the output FET (18) are connected such that the input and output FETs (16, 18) act as unit to gain amplifier.

Abstract: An apparatus includes a rotatably mounted magnetic rotor, a first coil mounted in proximity of the magnetic rotor, the first coil mounted such that, if the coil is flowing with electric current, the magnetic rotor is within immediate proximity of at least part of a magnetic field created by the coil. The apparatus includes a second coil mounted in proximity of the magnetic rotor, the second coil mounted such that, if the coil is flowing with electric current, the magnetic rotor is within immediate proximity of at least part of a magnetic field created by the coil. A current source is coupled to the first coil, for generating an AC signal and applying the AC signal across the first coil whereby an AC output signal develops across the second coil, the AC output signal having a magnitude that varies in relation to the rotational position of the rotor. A measuring circuit detects the AC output signal and develops therefrom a measure of the position of the rotor.

Abstract: A system for anti-lock brake and traction control has a control circuit comprising a microprocessor on a silicon die. Inputs from several variable reluctance wheel speed sensors are multiplexed to a single channel on the same die for signal processing including diagnostics, A/D conversion, square wave generation for each sensor by a state machine, end wheel speed determination from the square waves. The state machine algorithm tracks signal peaks and valleys and uses a dual hysteresis method of generating output transitions to capture all cycles of a signal having single cycle anomalies while rejecting noise. A single rear wheel sensor having twice the frequency of front wheel sensors for equal wheel speeds is processed twice as often as each front sensor. The diagnostics include detecting sensor and harness short and open circuits by comparison of signals to programmable thresholds and fault timing and latching by gauging open and short signals against programmable time limits.

Abstract: The maximum full level is determined in a fuel tank of undetermined size using a fuel level sender referenced to the tank bottom. A minimum full value is selected for a given type of tank and when the sender signal goes below a percentage of that value and subsequently goes above the minimum full value, a fueling event is recognized and the current fuel sender value is adopted as the maximum full value. Where a heavily filtered signal is used to minimize the effects of fuel slosh, the maximum full value is subject to increasing to higher values occurring during a short period after fueling to allow recovery of the filtered signal. An empty value is calibrated before the vehicle is initially fueled. A maximum empty level is initially set and if a lower level is measured when the ignition is turned on, the lower level is set as the empty value. This calibration is terminated when the tank is fueled above the minimum full value.