Abstract: Methods and apparatus concern testing a disk drive suspension. Testing includes moving a first portion of a suspension relative to a second portion. A pair of motors is mounted on the suspension. The testing further includes measuring an electrical signal that is intrinsically produced by the motors, combined in a circuit, in response to the relative movement. The testing further includes identifying a characteristic of the electrical signal and determining whether an orientation of one or both of the motors is reversed relative to an intended motor orientation based on the characteristic of the electrical signal. The testing can determine whether the orientation of both motors matches the intended motor orientation, whether the orientation of one motor is reversed in a same polarity condition, whether the orientations of both motors are reversed in a mutual reverse polarity condition, or whether the suspension has a mechanical or electrical defect.

Abstract: Methods and apparatus concern testing a disk drive suspension. Testing includes moving a first portion of a suspension relative to a second portion. A pair of motors is mounted on the suspension. The testing further includes measuring an electrical signal that is intrinsically produced by the motors, combined in a circuit, in response to the relative movement. The testing further includes identifying a characteristic of the electrical signal and determining whether an orientation of one or both of the motors is reversed relative to an intended motor orientation based on the characteristic of the electrical signal. The testing can determine whether the orientation of both motors matches the intended motor orientation, whether the orientation of one motor is reversed in a same polarity condition, whether the orientations of both motors are reversed in a mutual reverse polarity condition, or whether the suspension has a mechanical or electrical defect.

Abstract: A variable reluctance sensor for use with an ignition timing device includes a support tube insertable in a bore extending from a first end to a second end. A sensor housing is insertable in the bore, while a variable reluctance probe is disposed in the sensor housing.

Abstract: Method and apparatus for detecting failure in a piezoelectric element on a head suspension for a disk drive by clamping one end of the suspension, mechanically displacing and rapidly releasing the other end of the suspension, monitoring the electrical output of a piezoelectric element on the suspension and comparing the output with a predetermined output, using a clamp, motion actuator, and signal processor. The comparison may be with a predetermined voltage, and the output may be a natural frequency having a fundamental frequency corresponding to individual failure modes including adhesive fracture, piezoelectric element fracture, poling failure or a broken electrical connection.

Abstract: A variable reluctance sensor for use with an ignition timing device includes a support tube insertable in a bore extending from a first end to a second end. A sensor housing is insertable in the bore, while a variable reluctance probe is disposed in the sensor housing.

Abstract: A method for detecting failures in microactuator motors in head suspensions including exciting the head suspension at its natural resonant frequency, monitoring and evaluating the voltage produced by one or both piezoelectric elements in the motor, and comparing the voltage produced with one or more voltage waveforms corresponding to a properly functioning and mounted motor in response to a similar input. The method also includes applying a sweep frequency signal to provide visibility of a microcrack in the motor that may initially be concealed by plating on the motor.

Abstract: An ignition timing device for timing an engine having a timing port and a timing mark indicative of a position of a movable member. The ignition timing device includes a sensor adapted to be secured in the timing port to provide a timing mark signal indicative of presence of the timing mark. Also, an ignition sensor is adapted to provide an ignition signal indicative of the occurrence of an ignition spark. A filter receives the ignition signal and provides a filtered ignition signal. The filter filters ignition sparks of compression strokes from ignition sparks of compression and exhaust strokes of a selected cylinder to provide the filtered ignition signal. Also, the delay element is provided that receives the filtered ignition signal and provides a delayed signal having a selected delay from the filtered ignition signal. A comparator receives the timing mark signal and the delayed signal.

Abstract: A method for detecting failures in microactuator motors in head suspensions including exciting the head suspension at its natural resonant frequency, monitoring and evaluating the voltage produced by one or both piezoelectric elements in the motor, and comparing the voltage produced with one or more voltage waveforms corresponding to a properly functioning and mounted motor in response to a similar input. The method also includes applying a sweep frequency signal to provide visibility of a microcrack in the motor that may initially be concealed by plating on the motor.

Abstract: An ignition timing device for timing an engine having a timing port and a timing mark indicative of a position of a movable member. The ignition timing device includes a sensor adapted to be secured in the timing port to provide a timing mark signal indicative of presence of the timing mark. Also, an ignition sensor is adapted to provide an ignition signal indicative of the occurrence of an ignition spark. A filter receives the ignition signal and provides a filtered ignition signal. The filter filters ignition sparks of compression strokes from ignition sparks of compression and exhaust strokes of a selected cylinder to provide the filtered ignition signal. Also, the delay element is provided that receives the filtered ignition signal and provides a delayed signal having a selected delay from the filtered ignition signal. A comparator receives the timing mark signal and the delayed signal.

Abstract: An ignition timing device for timing an engine having a timing port includes a sensor securable in the timing port to provide a timing mark signal. An ignition sensor is adapted to provide an ignition signal. A comparator receives the timing mark signal and the ignition signal. The comparator provides an output signal indicative of substantial simultaneous occurrence of timing mark signal and the ignition signal. An indicator receives the output signal and is operable as a function thereof.