Abstract: A sensor (10) for sensing stress applied to an object (12), wherein the sensor includes a first core member (e.g., 100) aligned substantially parallel to the direction of applied stress and a second core member (e.g., 200) aligned substantially perpendicular to the direction of applied stress. A central core portion (18) connects the first and second core members (e.g., 100 and 200). An excitation coil (20) is operatively associated around the central core portion (18). The excitation coil (20) produces magnetic flux within the object (12) and the first and-second core members (e.g., 100 and 200). A first detection coil (e.g., 104) is operatively associated around the first core member (e.g., 100). A second detection coil (e.g., 204) is operatively associated around the second core member (e.g., 200). The first and second detection coils (e.g., 104 and 204) detect changes in the magnetic flux as affected by applied stress.

Abstract: A sensor (10) for sensing stress applied to an object (12), wherein the sensor includes a first core member (e.g., 100) aligned substantially parallel to the direction of applied stress and a second core member (e.g., 200) aligned substantially perpendicular to the direction of applied stress. A central core portion (18) connects the first and second core members (e.g., 100 and 200). An excitation coil (20) is operatively associated around the central core portion (18). The excitation coil (20) produces magnetic flux within the object (12) and the first and second core members (e.g., 100 and 200). A first detection coil (e.g., 104) is operatively associated around the first core member (e.g., 100). A second detection coil (e.g., 204) is operatively associated around the second core member (e.g., 200). The first and second detection coils (e.g., 104 and 204) detect changes in the magnetic flux as affected by applied stress.

Abstract: A parallel resistor array for progressively detecting brake lining wear. A plurality of conductors are embedded within a brake lining or otherwise disposed between the brake surface and an actuator. Each of the conductors is connected to a resistor that is in turn connected to an indicator circuit. The indicator circuit is also connected to the brake surface. The conductors have progressively increasing lengths extending from the brake surface to the actuator. When the brakes are applied, the brake surface may contact at least one of the conductors to close the indicator circuit. As the brake lining wears, each of the conductors progressively contact the brake surface when the brakes are applied thus progressively adding a resistor to the indicator circuit. The conductors and resistors are arranged in parallel and thus as the brake lining wears, the overall resistance in the indicator circuit progressively decreases.

Abstract: A brake status indicating system including a plurality of serially connected brake sensors having a first illumination source and a second illumination source connected to a voltage source through a first resistance and a second resistance where both the first and second illumination sources are activated when the brake sensors are within a normal operating range and where both the first and second illumination sources are deactivated when any one of the brake sensors are outside of a normal operating range. The second illumination source remains deactivated if a brake wear sensor is shorted to ground and the first resistance limits the electrical current flowing through a wheel bearing.

Abstract: An electronic circuit connected in series with one or more brake condition sensors having a first transistor and a second transistor connected to intermittently power an indicator lamp upon initial power-up to confirm circuit operational status and subsequently to activate the indicator lamp if the brake condition sensors are acceptable and to deactivate the indicator lamp if any one of the brake condition sensors is unacceptable.

Abstract: A brake actuator having a switch device mounted to an actuator housing with a spring member partially surrounding an actuator rod and adapted to contact a large diameter section of the actuator rod when brake wear causes the actuator rod to travel to a service limit position. In normal operation the spring member is separated from a small diameter section of the actuator rod. The switch device is mounted to a first end of the spring member having first and second electrical contacts which extend and electrically contact a conduction plate attached to a second end of the spring member as long as the brake actuator rod has not traveled to the service limit.

Abstract: An apparatus (10) and an associated method for testing an acceleration sensor assembly (14), which is preferably an accelerometer assembly. An electrical exciter (34) is operated in response to an excitation signal (32) from a signal generator (30). The exciter (34) applies oscillating excitation to the accelerometer assembly (14). An initial excitation is applied to the accelerometer assembly (14) by the exciter (34). The frequency of the initial excitation is varied over a range of frequencies via a signal (62) from a frequency range sweep function (56) to the signal generator (30). The output of the accelerometer assembly (14) is monitored during application of the initial excitation over the range of frequencies. A frequency value associated with a predetermined response in the output of the accelerometer assembly (14) is stored. The excitor (34) subsequently applies a test oscillating excitation at the stored frequency value to the accelerometer assembly (14).

Abstract: A single wire electrical conductor is serially connected to a first switch mounted to a brake slack adjuster and serially connected to a second switch embedded in a brake lining. The closing and opening of the first and/or second switch causes electrical changes that are measured in an electronic control unit for use in signaling the operator of the need for brake service.

Abstract: An apparatus includes an accelerometer (24) for providing an analog acceleration signal indicative of crash acceleration. A sigma-delta A/D converter (26) is operatively connected to the accelerometer (24) for providing a pulse-width-modulated gate enable signal (GES) with a value indicative of the acceleration signal. The GES signal is ANDED with a clock signal to produce a pulse-density signal (CNT) indicative of the acceleration signal. A monitoring circuit determines (i) whether at least one pulse-density signal occurs when a gate enable signal is HIGH (FLAG 1), and (ii) whether the pulse-density signal occurs when the gate enable signal is LOW (FLAG 2). Other embodiments test to see if the gate enable signal is either full scale ON (FLAG 3) or full scale OFF (FLAG 4) by using a second crash sensor (64). Timing circuits (302, 316) are used to ensure that the pulse duration of at least one pulse-width modulated gate enable signal is greater than predetermined value within a predetermined time period.

Abstract: An apparatus for trimming gain of an accelerometer to a desired gain value G.sub.t. The apparatus includes an accelerometer for providing an electric signal indicative of experienced acceleration with an intrinsic gain G.sub.s. An amplifier amplifies the accelerometer signal with an amplification value responsive to the accelerometer's intrinsic gain G.sub.s so as to have the desired gain value G.sub.t.

Abstract: A brake lining temperature and wear sensor having a plurality of serially connected wire loops and a resistive temperature sensor having a lower range of resistance than any one resistor mounted in a cavity formed in the brake lining where a plurality of resistors are connected one to each wire loop to be sequentially connected to a sensor circuit as the brake lining wears and breaks each wire loop. A control unit provides an electrical current to the sensor circuit and monitors the electrical potential across the plurality of wire loops and the resistive temperature sensor and then generating an output signal representing the temperature and wear of the brake lining. In an alternate embodiment, a capacitor is connected across the plurality of wire loops and a resistive temperature sensor with a large range of resistance is used to monitor the brake lining temperature.

Abstract: A method and apparatus for controlling a vehicle power assist steering system. The apparatus includes a control circuit for controlling the power assist as a function of sensed vehicle speed and applied steering torque. The control circuit includes a circuit for providing a pulse-width modulated signal having a duty cycle that varies as a function of vehicle speed. the control circuit further includes a torque signal amplifier having a gain that is controlled by the pulse-width modulated signal. A filter network averages the value of the output of the torque signal amplifier. The average value is a power assist control signal used to control the power assist.

Abstract: An anti-theft device for automobile vehicles disables the vehicle's starter ignition system unless a coded resistive element is inserted into the device by the vehicle's operator. A control system senses the value of the coded resistive element and enables the starter system if the sensed value is correct. A latching circuit latches-in enablement of the starter system after an arming switch is activated and the resistive element has been removed, serving to provide a valet function. A lock-out circuit prevents enablement of the starter system for a prescribed time period following an unauthorized attempt at enabling the system, as when an incorrect resistive element is inserted into the device. The device employs a normally closed relay to enable the starter system so that failure of those portions of the device which are most likely to fall does not affect normal operation of the starter system.