Abstract: An adaptive audio processor for stereo AM broadcast signals includes independent signal processing paths. Each path has a variable lowpass filter and a matrix and variable Q 10 kHz notch filter to form LEFT and RIGHT channel signals with a 10 kHz notched pass band determined by adjacent channel noise. A 10 kHz pass band signal representative of adjacent channel noise from one of the signal processing paths is compared to a reference to generate a correction signal that is fedback to control the lowpass and notch filters. The correction signal adjusts the pass band and Q of the lowpass and notch filters so that the effects of adjacent channel noise are minimized. Other receiver signals which are reflective of the quality of the received broadcast signal, e.g., the AGC signal, an excess modulation signal, and a receiver microprocessor signal are similarly employed to control the lowpass and notch filters.

Abstract: A Stop On Station (SOS) circuit for a AM and FM radio receivers evaluates field strength of a received station signal and in addition measures and evaluates the frequency of the IF signal so as to assure that the received signal is essentially centered at the IF frequency to identify candidate stations signals which are suitable for listening. The IF frequency for a received candidate station signal is evaluated for an evaluation period of time (e.g., for 40 milliseconds). During each 40 millisecond period, fifteen samples of the frequency of the IF signal are counted and evaluated. If the frequency of the measured signal falls within acceptable limits, a four stage binary persistence counter is incriminated. If a count of 12 or more out of the 15 possible counts is accumulated therein during a 40 ms evaluation period, a station signal is considered to be suitable from a standpoint of received frequency and a "frequency pass" signal is generated.

Abstract: The firing circuit for an inflatable restraint for a vehicle includes a storage capacitor which is charged from a 36 volt regulated power supply. The power supply is energized from the vehicle battery through the ignition switch. Both the battery and the capacitor are connected with the squib through impact sensor switches. A computer monitors the voltage at the squib to determine if an energy source is connected with the squib. The energization of the regulated power supply is delayed for a predetermined time interval following ignition switch activation to insure that the voltage initially monitored by the computer is applied to the monitoring junction from the battery and not from the capacitor.

Abstract: An expert system scheduler is disclosed which uses heuristics developed by an experienced factory scheduler. The scheduler uses these heuristics to generate schedules. Forward and backward scheduling is used at different stages of the schedule generation process.

Abstract: An ajustable switched capacitor circuit comprises a first stage, a second stage and a switched capacitor circuit coupling the output of the first stage to the input of the second stage. The operating parameters of the second stage are a function of the effective resistance of the switched capacitor coupling circuit. An attenuator interposed between the output of the first stage and the input of the switched capacitor coupling circuit controls the charging voltage of the switched capacitor coupler thereby controlling its effective resistance and parameters of the output stage. The signal loss through the attenuator is continuously adjustable responsive to an external control voltage to obtain continuous control of various output stage parameters. The output stage may comprise a filter having the parameters of its transfer function determined by the effective resistance of the switched capacitor coupling circuit.

Abstract: A differential operational amplifier comprises a differential input circuit that provides a differential output signal to a plurality of independent output circuits. The gains of the differential input circuit and one output circuit are set by a fixed bias source. A variable bias source controlled by an external signal determines the gain of each other output circuit so that various attenuation characteristics are obtained in the other output circuits without affecting the operating conditions of the operational amplifier. A feedback element between the output of the one output circuit and the differential input circuit assures gain stability.

Abstract: The invention relates to a motor vehicle radio with an automatic volume control device (20) and a manual volume-setting device (14). The automatic volume control device (20) is fed with a speed signal detected by a speed sensor and delivers a volume signal associated with the detected speed signal. The manual volume-setting device (14) generates a volume signal corresponding to the volume which has been set. A two-position switch (16) is provided for selectively applying the volume signal from the automatic volume control device (20) or from the manual volume-setting device (14) to an output stage (12) which feeds the loudspeakers (13). When the manual volume-setting device (14) is switched on, following a detection signal for a desired vehicle speed, the volume signal corresponding to the volume which has been set can be stored in a storage and control circuit (23) of the automatic volume control device (20).

Abstract: An audio detector circuit forms L+R and L-R audio signals from an intermediate frequency compatible quadrature amplitude modulated signal in the form (1+L+R)cos(fct+.phi.) where .phi. contains phase modulated L+R and L-R signals. An envelope detector generates an L+R audio signal and in-phase and quadrature phase detectors produce L+R and L-R audio signals, respectively. The difference between L+R outputs of the envelope and in-phase detectors are amplified to generate a cosine correction signal. Each detector includes a differential operational amplifier having an field effect feedback transistor coupled between each amplifier output and the corresponding input and an field effect transistor coupling the compatible quadrature amplitude modulated signal to the operational amplifier inputs.

Abstract: An inverting amplifier useful in an oscillator circuit includes complementary serially connected first and second metal-oxide-semiconductor field effort transistor (MOSFETS) and first and second resistors, two capacitors, a first feedback circuit having two MOSFETS in series with a third resistor and a second feedback circuit having two MOSFETS and a fourth resistor in series. Each feedback circuit provides a feed back path from the drain of one of the output transistors to the gate thereof. The resistors are polysilicon type resistors and have a negative thermal coefficient. The amplifier has a very stable output signal amplitude which is essentially independent of integrated circuit manufacturing processing variations and operating temperature variations within useful ranges.

Abstract: A vehicle anti-theft device is disclosed which includes an electronically erasable programmable read only memory (EEPROM) which stores a modifiable code which must be matched by an input code in order to start the vehicle. The ignition key includes a resistor pellet, engaged by contact in the ignition lock assembly, which is measured to provide the input code. To avoid problems associated with intermittent contact engagement with the resistor pellet, circuitry is provided to control the resistor measurement cycle.

Abstract: An adaptive cruise control system for motor vehicles uses a video camera and digital processing techniques to enable one vehicle to follow another at a substantially constant or safe distance on a highway under favorable weather conditions.

Abstract: A method of operating optical pattern recognition apparatus which relies upon second opinions in which stored offset coordinates match one another within a predetermined tolerance to avoid unnecessarily high numbers of rejects, undesirable levels of risk in terms of pattern misalignments, or excessive cycle times in terms of unnecessary looping through different grey level thresholds.

Abstract: A Phase Locked Loop (PLL) circuit includes a control signal generator, a digital phase detector, logic gates, a charge pump (charge/discharge circuit), a transmission gate, a loop filter, a lead-lag filter and a voltage controlled oscillator (VCO). Outputs of the digital phase detector are coupled through the logic gates to inputs of the charge pump. An output of the charge pump is coupled to the capacitor and to a first input/output of the transmission gate. A second input/output of the transmission gate is coupled to an input of the loop filter whose output is coupled to an input of the VCO whose output is coupled to a first input of the digital phase detector. A second input of the digital phase detector is coupled to a source of a reference frequency signal. The control signal generator generates non-overlapping complementary control signals with one of same connected to the logic gates and the other connected to the transmission gate.

Abstract: A general purpose expert system architecture for diagnosing faults in any one of a plurality of machines includes a machine information database containing information on characteristics of various components of the machines to be diagnosed and a sensory input database which contains vibration data taken at predetermined locations on each of the machines. The system knowledge base contains a plurality of general rules that are applicable to each of the plurality of machines. The generality of diagnosis is accomplished by focusing on components that make up the machine rather than individual machines as a whole. The system architecture also permits diagnosis of machines based on other parameters such as amperage, torques, displacement and its derivatives, forces, pressures and temperatures. The system includes an inference engine which links the rules in a backward chaining structure.

Abstract: An integrated circuit FM detector which compensates for variations in semiconductor manufacturing process and temperature employs a pair of serially connected switched capacitor-operational amplifier combinations. The first combination is a frequency to voltage converter which uses a switched capacitor input circuit which is clocked at the frequency of the input signal, an operational amplifier and a feedback resistor. The second combination is a compensation circuit which uses an input resistor, a feedback switched capacitor circuit and an operational amplifier. The feedback switched capacitor circuit is clocked at a fixed rate. Reversal of the roles of the resistor and the switched capacitor in the first and second combinations compensates for both temperature and manufacturing process variations.

Abstract: An FM stereo radio circuit has an ultrasonic noise detector and an amplitude noise detector each for detecting impulse noise by developing an average noise signal and comparing the average noise signal with an attenuated value of the instantaneous noise signal to generate a noise flag. A dual mode circuit normally operates as a low pass filter for a deemphasis function and is switched by the noise flag to operate as a sample and hold circuit which blanks the noise pulse. The dual mode circuit uses a switched capacitance design and is driven by clock signals to serve as a filter. The clock signals are stopped by the noise flag to effect the sample and hold function.

Abstract: An analog/digital voltage controlled oscillator includes a voltage to pulse converter which responds to a control voltage to generate appropriate control pulses to change the mode of operation of a divider to thereby vary the output frequency of the oscillator.

Abstract: A phase locked loop (PLL) with a narrow bandwidth, and small phase noise which is particularly useful in a FM stereo decoder includes both analog and digital circuitry and has the advantages of both types of systems, performing better than standard PLL's without the need for any external components. An externally referenced digital voltage controlled oscillator, establishes the center frequency of the PLL while analog portions of the circuit permits accurate locking to the input signal and provides a high level of quietness of the system.

Abstract: A Phase Locked Loop (PLL) circuit includes a compensation circuit which corrects for non-linear sensitivity of a varactor of a voltage controlled oscillator (VCO) which is part of the circuit. The varactor is employed as a capacitance tuning element. The compensation circuit controls the sensitivity of a charging/discharging circuit (a charge pump) of the PLL circuit with a feedback signal which is derived from an input to the VCO. The sensitivity characteristic of the charge pump is made the complement of the non-linear portion of the VCO sensitivity characteristic.

Abstract: An integrated, remote sensing and reactive detection system is provided for detecting and confirming the presence of hazardous microbursts, macrobursts, and windshears in the general flight path of an aircraft. An infrared remote sensing system is used to seek out, detect, and provide advanced alerts of thermal gradients ahead of an aircraft which correlate with windshear conditions. The measurement of atmospheric temperature is accomplished by a scanning, multi-spectral radiometer that sweeps an approximate 60 degrees path in front of the aircraft at about a 5 hertz rate. The radiometer employs two rows of detectors that are slightly offset resulting in two simultaneous measurements of temperature that are about 7 degrees apart in elevation angle.