Abstract: A motor vehicle control system includes a pair of cameras for producing first and second images of a passenger area. A distance processor determines distances that a plurality of features in the first and second images are from the cameras based on the amount that each feature is shifted between the first and second images. An analyzer processed the distances and determine a size of an object on the seat. Additional analysis of the distance also may determine movement of the object and the rate of that movement. The distance information also can be used to recognize predefined patterns in the images and thus identify the object. A mechanism utilizes the determined object characteristics in controlling operation of a device, such as deployment of an air bag.

Abstract: A sonic back-up proximity sensor employs a first sonic transducer and a second sonic transducer mounted on a rearward portion of a riding lawn mower to create three discrete zones of protection. The first sonic transducer has an associated first region of coverage, or sector, and the second sonic transducer has an associated second sector. The first sonic transducer and second sonic transducer are directed toward one another such that the first sector and second sector at least partially overlap. The overlapping portion of the first sector and second sector provides redundant coverage in an area directly behind the lawn mower. The non-overlapping portion of the first sector defines a second protection zone on one side of the lawn mower. The non-overlapping portion of the second sector defines a third protection zone on a second side of the lawn mower.

Abstract: A control circuit is provided for transferring power and communication signals through a wireless coupling device in a vehicle steering column. The device can comprise a rotary transformer having a primary and secondary magnetic structure respectfully associated with the wheel side and column side of the steering column. A squib power circuit transforms a high energy power signal suitable for firing an air bag from the column side to the wheel side. A low energy power circuit generates a signal from the column side to the wheel side suitable for operating isolated wheel side electronics, such as cruise control and the like. A tone encoder and decoder circuit communicates low level control signals suitable for signaling wheel side commands from the wheel side to the column side. The low energy power circuit and the tone encoder circuit operate simultaneously and continuously without signal debilitating interaction.

Abstract: A control circuit is provided for transferring power and communication signals through a wireless coupling device in a vehicle steering column. The device can include a rotary transformer having a primary and secondary magnetic structure respectively associated with the wheel side and column side of the steering column. A squib power circuit transforms a high energy power signal suitable for firing an air bag from the column side to the wheel side. A low energy power circuit generates a signal from the column side to the wheel side suitable for operating isolated wheel side electronics, such as cruise control and the like. A tone encoder and decoder circuit communicates low level control signals suitable for signaling wheel side commands from the wheel side to the column side. The low energy power circuit and the tone encoder circuit operate simultaneously and continuously without signal debilitating interaction.

Abstract: A control circuit drives the coil of a contactor in response to a control voltage being applied. The control circuit includes a power supply that produces a regulated output voltage from the control voltage. The onset of the regulated output voltage starts a timer which controls the width of pulses produced by a PWM controller. The pulses control a transistor that applies the control voltage to the coil. Initially the pulses cause a high current to flow through the coil to close the contactor and after an interval of time the timer signals the PWM controller to shorten the pulses which applies lesser current to the coil to keep the contacts closed. A flyback circuit provides a relatively low reverse voltage drop path in parallel with the coil to maintain the electromagnetic field during the periods between the pulses. When the control voltage is removed to open the contactor, the flyback circuit provides a high reverse voltage drop path to promptly dampen the coil current.

Abstract: An improved method and servo control apparatus (C) is provided for controlling the motion of a linear electric motor (A) which in turn generates motion command signals to various apparatus such as a hydraulic steering system (B). Preferably, the servo control apparatus (C) includes a power supply circuit (60), a servo amplifier circuit (62), a pulse width modulation circuit (64), an H-bridge drive circuit (66) and an inductive position sense circuit (68). The voltage at a node (42) between coil pairs (38, 40) in the motor (A) is sensed and synchronously demodulated using transmission gates (222, 224) to develop a DC signal representative of armature (30) position from a center location. The signal on a current shunt resistor (200) is synchronously demodulated by transmission gates (208, 209)to generate a signal, the phase of which is determined with respect to the motor drive signal. The phase signal directly indicates whether the armature is off center towards drive coil 38 or drive coil 40.

Abstract: A control system for a washing machine having a transducer mounted on the exterior of the washing receptacle wall and operable to generate acoustic vibrations in the receptacle wall during fluid filling of the receptacle. A receiver detects sound waves within the receptacle generated by the wall vibrations and generates in fill signal indicative of the sound waves. Circuitry is provided for analyzing the fill signal and determining from the acoustic signature of the fill signal the occurrence of total immersion of articles in the fluid; and, the circuitry sends a signal which is operable to then shut off the fluid fill valve.

Abstract: An adjustable frequency oscillator 2 is provided by a comparator timer 4 having a potentiometer 6 at its output 8 for concurrently changing both charging current and threshold trip voltage to control the frequency of oscillation of the comparator output. The oscillator is ideal for proximity switch applications, particularly photoelectric type proximity switches, for timing a delayed output signal following a given sensed condition.

Abstract: A comparator timer 2 is disclosed in which charging current and threshold trip voltage are both adjusted with a single potentiometer 6. Moving the pot wiper 8 in one direction increases the threshold trip voltage at the reference input terminal 12 of the comparator 4, such as the minus terminal of an operational amplifier, and at the same time decreases the capacitor charging current to the comparing input terminal 16, such as the plus terminal of the op amp, to lengthen the timing interval. Moving the pot wiper 8 in the other direction decreases threshold trip voltage and concurrently increases capacitor charging current to shorten the timing interval. The circuit affords expanded timing range, reduced power consumption and improved adjustment resolution, which are ideal for proximity switch applications, particularly photoelectric type proximity switches.

Abstract: A fast turn-off FET circuit is provided by a bipolar transistor in the gate circuit of the FET. The bipolar transistor is driven into conduction by residual charge in the gate to source capacitance of the FET upon turn-off of the latter due to removal of gate drive. Conduction of the bipolar transistor provides faster discharge therethrough of the FET gate, whereby to facilitate faster FET turn-off without reverse gating current and its attendant auxiliary power supply.

Abstract: A three terminal bidirectional FET circuit is provided by first and second MOSFETs connected source to source in series relation between first and second main terminals, and by gating circuitry including current source means connected to a gate terminal for driving the FETs into conduction. A resistor is connected between a point common to the FET sources and a point common to the FET gates and the current source, such that the gate to source voltage for each FET is the same regardless of the relative polarity of the main terminals.

Abstract: A fast turn-off MOSFET circuit is provided by a JFET in the gate circuit of the MOSFET which is connected to the same gate drive terminal as the MOSFET. The JFET becomes conductive upon turn-off of the MOSFET due to removal of gate drive. Conduction of the JFET provides faster discharge therethrough of residual stored charge on the MOSFET gate, whereby to facilitate faster MOSFET turn-off. A zener diode is connected in the gating circuitry and has a greater breakover voltage than the pinch-off voltage of the JFET, such that during turn-on, gate drive first pinches OFF the JFET and then charges up the MOSFET gate to drive the MOSFET into conduction.

Abstract: A bidirectionally source stacked FET circuit is provided with drain-referencing of the gating circuitry, instead of source-referencing. This requisite gate to source potential to charge the gate and effect conduction of the FETs is provided by referencing the gate circuitry to a common anode point of diodes having their cathodes connected to the drains of the FETs. The common anode point is at substantially the same potential as the common source point of the FETs. The gate charging potential is provided by current from a current source through a resistor to the common anode point, which IR drop establishes the requisite gate voltage to drive the corresponding FET into conduction regardless of the polarity of first and second main terminals at respective FET drains.

Abstract: Stacked gating circuitry is provided for controlling a plurality of pairs of power FETs stacked in series, each pair being bidirectionally source to source connected for AC conduction. All the power FETs turn on from a single gate terminal through series connected current sources, one current source for each FET pair. The FETs turn on in ripple effect.

Abstract: Gating circuitry is provided for controlling a plurality of power FETs stacked in series and parallel. A plurality of parallel circuit branches are connected between main terminals, each branch having a plurality of series connected power FETs. All power FETs are turned ON and OFF from a single gate terminal. Trigger means responds to one polarity gate signal to supply gate charging current to all the FETs. The trigger means responds to the opposite polarity gate signal to directly deplete gate charge from selected power FETs. The remaining power FETs have their gate charges depleted through individual self turn-off circuits between their gate and source which becomes conductive in the absence of gate charging current.

Abstract: A bidirectional power FET circuit for AC application has a plurality of pairs of enhancement mode power FETs. Each pair has first and second power FETs connected drain to drain in series relation. The pairs are stacked in series between first and second main terminals. A plurality of gating circuits, one gating circuit for each power FET pair, are stacked in series for driving the power FET pairs sequentially into conduction from a single gate terminal.

Abstract: A fast turn-off FET circuit is provided by regeneratively coupled bipolar transistors in the gate circuit of the FET which are driven into latched conduction by residual charge in the gate to source capacitance of the FET upon turn-off of the latter due to removal of gate drive. The regeneratively coupled bipolar transistors remain in latched conduction until the FET gate charge is depleted. Conduction of the bipolar transistors provides faster discharge therethrough of the FET gate, whereby to facilitate faster FET turn-off without reverse gating current and its attendant auxiliary power supply.

Abstract: A three terminal bidirectional FET circuit is provided by first and second MOSFETs connected drain to drain in series relation between first and second main terminals, and by gating circuitry providing requisite gate drive to a corresponding FET regardless of the polarity of its correspondent main terminal. A current source is connected to a common point between the FET gates, which common gate point is referenced through a resistor and a pair of diodes to the most negative of the main terminals.

Abstract: A fast turn-on FET circuit is provided by a constant current source and fast turn-on capacitor combination in the gate circuit of the FET. At turn-on, a bypass capacitor momentarily short-circuits a control resistor in the current source such that a momentarily higher current is supplied by the current source to the FET gate until the capacitor is charged, whereafter constant current as controlled by the resistor is supplid to the FET gate circuitry to maintain conduction.