Abstract: A system having an accelerometer and a micro-controller responsive to acceleration signals for deploying an air bag as well as activating a pretensioner upon frontal impact includes an algorithm for activating the pretensioner upon rear impact. A frontal crash algorithm is executed when the acceleration exceeds a negative threshold and a rear impact algorithm is enabled when the acceleration exceeds a positive threshold. Rear impact severity is tested by integrating positive acceleration samples and issuing an activation command when the integrated value attains a severity threshold value. Noise immunity results from the positive threshold and from resetting the integrated value to zero whenever a negative acceleration sample intervenes in the severity test.

Abstract: An inflatable restraint system includes a diagnostic circuit which measures the resistance of an external deployment path containing a squib. The circuit supplies a test current through the path and measures the voltage across the path which is monitored by a microprocessor. A vehicle battery supplies the power to the system and is connected to a constant current source in series with the external path to provide the test current. A current limiting device between the external circuit and ground comprises a current sink allowing a maximum safe current in the external circuit in the event of inadvertent application of battery voltage to the external circuit and, during a normal resistance test, imposes only a small voltage drop on the test current circuit.

Abstract: Back lighting for an transmissive display panel such as a transparency or a liquid crystal display for direct viewing or image projection is afforded by a light source spaced from the display panel and an intervening light coupler comprising a tapered duct with reflective inner walls such as a frustoconical mirror. The small end of the duct is adjacent the light source and may include a diffuser film to enhance light uniformity at the display. Light reflection from the reflective walls provides off-axis viewability with substantially uniform brightness. The light coupler is useful in a vehicular head up display.

Abstract: An adaptive threshold circuit for use with a magnetic type of sensor that has a pick-up coil. The pick-up coil has an alternating voltage induced therein when a slot formed in a wheel rotates past the sensor. The circuit produces a square wave pulse voltage during positive half-cycles of the voltage generated in the pick-up coil. The circuit includes a digital to analog converter the input of which is connected to a pulse counter. The output of the converter is a function of the count magnitude in the counter and provides a variable threshold voltage that is compared by a voltage comparator with a voltage that is a function of the magnitude of the voltage generated in the pick-up coil. The circuit has an input circuit connected to the pick-up coil that includes a voltage attenuating circuit and a diode.

Abstract: Air bags are deployed by firing circuits each containing a squib in series with a common control switch, and a control containing an accelerometer and a microprocessor for operating the switch to deploy the air bags. To diagnose shorts, a current source feeds a trickle current through each squib and a current limited voltage regulator across the switch passes the combined trickle currents to ground. The microprocessor senses the voltage across the switch via an A/D converter. That voltage goes low for a short to ground and high for a short to battery voltage.

Abstract: A single glass envelope contains fixed anode segments on the glass surface and a silicon substrate mounted on the same surface. The silicon substrate contains an active matrix vacuum fluorescent anode array as well as serial interface circuitry and a driver circuit for each of the AMVFD and the fixed segment display to minimize the number of input pins in the lead frame of the envelope. Aluminum traces on the glass surface are wire bonded to the substrate and extend to the fixed segments and to the lead frame pins.

Abstract: A system for anti-lock brake and traction control has a controller 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, and wheel speed determination from the square waves. 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. Common mode noise rejection is accomplished by detecting common mode aberration and disabling an A/D converter during the aberrations.

Abstract: A rotational accelerometer has a pair of coplanar, operationally independent linear acceleration sensors. Coplanarity is provided by a unitary substrate which forms the base structure of the operationally independent linear acceleration sensors.

Abstract: A combiner is pivotally mounted for movement between an operating position in the line of sight of an operator and a storage position. A sector gear fixed to the combiner engages a slidable rack so that sliding the rack causes pivotal movement of the combiner. A control knob and stem are mounted for rotary movement and translation. A cam rotated by the knob engages followers on the rack to slide the rack upon knob translation or rotation. Knob translation effects movement of the combiner between operating and storage position, and when in operating position, knob rotation effects fine adjustment of the combiner to adjust image position.

Abstract: An improved squeegee for screen printing a thick film ink onto a substrate of a microelectronics circuit in order to form a thick film on the substrate. The squeegee is specifically configured to eliminate the creation of voids in a thick film deposited using the squeegee by enhancing the flow characteristics of the thick film ink as it is forced through a printing screen by the squeegee. Improved flow characteristics are achieved be appropriately configuring the cross-sectional profile of the squeegee in order to localize the printing forces on the ink at the working edge of the squeegee, in order to prevent ink ahead of the working edge from prematurely filling the openings in the screen.

Abstract: A molding apparatus and a molding method are provided which enable leads which project from an electronic housing, such as a housing configured to receive an accelerometer, to be formed during the molding operation in which the housing is formed. As a result, the leads used in the molding operation can be in an as-stamped, unformed condition, so as to facilitate handling and loading of the leads into the molding apparatus. In addition, because forming occurs during the molding operation, subsequent secondary forming operations are not required to achieve the desired configuration for the leads.

Abstract: A crystal oscillator circuit that provides a low distortion clocking signal. The oscillator circuit incorporates an inverter circuit in combination with a diode connected transmission gate circuit. The transmission gate circuit includes two MOSFETs connected between input and output nodes of the inverter circuit. When the current at the input node goes high and the current at the output node goes low, one of the two transmission gate circuit MOSFETs will begin conducting such that current at the input node will be transferred to the output node, thus decreasing the voltage difference between the two nodes. Likewise, when the current at the output node goes high and the current at the input node goes low, the other MOSFET of the transmission gate circuit will begin to conduct such that current is transferred from the output node to the input node, again reducing the voltage difference between the input and output node.

Abstract: A box-like molded housing with an open front has a flexible printed circuit wrapped around it, the printed circuit having a terminal array attached to a housing flange adjacent the front opening. A frame having a translucent web or filter covers the open front and contains a liquid crystal cell. A slot in the frame contains an elastomeric connector for joining terminals on the cell with terminals on the printed circuit to provide control signals to the cell. The housing interior is a reflector cavity and contains lamps for illuminating the web and the cell through the web. The printed circuit carries surface mount components, supplies power to the lamps, and has a contact array for connection to spring contacts of an external connector.

Abstract: A circuit and method are provided for generating a clipping distortion detector output signal for an integrated circuit audio amplifier which is independent of operating temperature and supply voltage. The system includes an audio amplifier having a voltage gain, a first input for receiving input voltage and an output for generating an amplified output voltage. A supply voltage is supplied to the audio amplifier and the supply voltage determines the maximum amplified output voltage. A comparison voltage is generated which is indicative of the output voltage divided by the voltage gain. A clip detector voltage comparator receives the input voltage and the comparison voltage and provides a clipping distortion detect signal when the input voltage deviates from the comparison voltage in excess of an offset voltage which is indicative of detection of excessive clipping distortion.

Abstract: A data processing system having a mathematically consistent condition code architecture is disclosed for implementing single instruction range checking and limiting operations. The data processing system includes condition code flags that are set to provide indications of the occurrence of arithmetic overflow and the direction of the arithmetic overflow for all of the possible arithmetic operations that can be performed by an arithmetic logic unit within the digital processing system. Based upon the indicated occurrence of arithmetic overflow and the direction of the overflow, the numeric value of a software variable generated by one of the arithmetic operations is limited to an appropriate upper or lower bound of a predetermined range of acceptable values, if the numeric value was generated with the occurrence of arithmetic overflow, or the numeric value was generated without the occurrence of overflow, but was outside of the acceptable range of values.

Abstract: A two-step deployment control method for a supplemental inflatable restraint (SIR) in a vehicle. The deployment decision includes a "time to wait" step in which the control determines "when to deploy", and a "severity" step in which the control determines "whether to deploy". The "time to wait" step is based on an estimation of occupant displacement due to the crash, and the "severity" step is based on an estimation of the crash severity. The control method is modified to initiate earlier deployment when the acceleration data is indicative of a localized impact which does not involve the full front structure of the vehicle, such as an angle or pole impact.

Abstract: A circuit and method are provided for generating a clipping distortion detector output signal for an integrated circuit audio amplifier which is independent of operating temperature and supply voltage. The system includes an audio amplifier having a voltage gain, a first input for receiving an input voltage and an output for generating an amplified output voltage. A supply voltage is supplied to the audio amplifier and the supply voltage determines the maximum amplified output voltage. A comparison voltage is generated which is indicative of the output voltage divided by the voltage gain. A clip detector voltage comparator receives the input voltage and the comparison voltage and provides a clipping distortion detect signal when the input voltage deviates from the comparison voltage in excess of an offset voltage which is indicative of detection of excessive clipping distortion.

Abstract: A band-gap voltage regulator having a self-regulating characteristic which improves the operation of the regulator includes a feedback circuit coupling a gain stage of the regulator to a voltage reference circuit which influences the regulated voltage. Changes in the operation of the gain stage which would otherwise change the regulated voltage produce counteracting changes in the voltage reference circuit, causing the supply voltage to remain substantially constant.

Abstract: A twist-in socket for insertion into a printed circuit assembly has a molded plastic body, conductive paths deposited or plated onto the surface, and an LED and a resistor connected to the paths for energization by the printed circuit. The sockets are molded in arrays, plated to form the conductive paths, the components inserted by automatic machines and flow soldered to the paths, and then individual sockets are snapped off the array. In one embodiment, the LED and resistor have leads extending through holes in the socket to reach the conductive paths. In another embodiment, surface mount components are used, and plated-through holes in the socket couple the path to the surface mount components.

Abstract: A method for tuning and aligning an electronically tuned FM broadcast receiver is described. The system described compensates for the mismatch of component values between the antenna and RF amplifier tuned circuits, and the IF offset between the local oscillator frequency and the center frequencies of the antenna and RF resonant circuits by developing independent tuning signals for the circuits. The system also provides temperature compensation, and can be aligned without mechanically adjusting inductors and/or capacitors in the tuned circuits.