Abstract: A body of an electrostatic chuck comprises mesas disposed on a polished surface of the body. Each of the mesas comprises an adhesion layer disposed on the polished surface of the body, a transition layer disposed over the adhesion layer, and a coating layer disposed over the transition layer. The coating layer has a hardness of at least 14 Gpa. The body further comprises a sidewall coating disposed over a sidewall of the body. A method for preparing the body comprises polishing the surface of the body and cleaning the polished surface. The method further comprises depositing the mesas by depositing the adhesion layer on the body, the transition layer over the adhesion layer, and the coating layer over the transition layer. Further, the method includes, polishing the mesas.

Abstract: Systems and methods for detecting the dynamic train-to-rail shunting performance of a train as it is moving along the rails of a railroad track. The systems and methods use portable equipment temporarily installed at a site where it is desired to test the shunting of one or more trains or the electrical equipment installed at the track. The systems and method use sensor plates and a high speed recording system to simultaneously capture measured train-to-rail shunting characteristics and the positioning of a train's axles and any rail conditions impacting the measurements. The captured information can be used to fine tune the train, the electrical equipment installed at the track and/or to design new devices.

Abstract: A system, apparatus and method for light diffusion and testing fixtures. The system includes remote derangement controls to test the operation of a battery backup system associated with a fixture. The light fixture may incorporate light diffusion features including back mounted light sources, channeled corners in a translucent material and/or pitted surfaces of a translucent material. The system may further include remote monitoring elements and/or sensors to evaluate proper operation of the light diffusion characteristics of a fixture during operation of the battery backup system.

Abstract: An illuminated assembly includes a substrate that is rigid so as to maintain a shape, the substrate having a first terminal surface and a second terminal surface. The assembly includes at least one channel defined into the substrate, the at least one channel having: an exposed portion defined on the first terminal surface of the substrate to define an indicia for display, a base portion defined between the first and second terminal surfaces of the substrate, and two channel walls extending from the exposed portion to the base portion. The assembly includes at least one light source between the exposed portion and the base portion of the at least one channel. The assembly includes a compound defined in an intermediate portion of the at least one channel, the intermediate portion extending from the at least one light source to the two channel walls, the exposed portion, and the base portion.

Abstract: Methods and systems of processing sensor signals to determine motion of a motor shaft are disclosed. This disclosure relates to the processing of sequences of pulses from a sensor for computing the motion of an electric motor output shaft. Furthermore, this disclosure relates to the processing of two sequences of pulses from sensor outputs, which may be separated by only a few electrical degrees, to compute the motion of an electrical motor output shaft while using a limited bandwidth controller. Motor shaft direction, displacement, speed, phase, and phase offset may be determined from processing the sensor signals.

Abstract: Aspects of a method and system for configuring a transformer embedded in a multi-layer integrated circuit package are provided. In this regard, a windings ratio of a transformer embedded in a multi-layer IC package bonded to an IC may be configured, via logic, circuitry, and/or code in the IC, based on signal levels at one or more terminals of the transformer. The transformer may comprise a plurality of inductive loops fabricated in transmission line media. The integrated circuit may be flip-chip bonded to the multi-layer package. The IC may comprise a signal strength indicator enabled to measure signal levels input to or output by the transformer. The windings ratio may be configured via one or more switches in the IC and/or in the multi-layer package. The IC and/or the multi-layer package may comprise ferromagnetic material which may improve magnetic coupling of the transformer.

Abstract: An advanced coating for electrostatic chuck used in plasma processing chamber is provided. The advanced coating is formed using plasma enhanced physical vapor deposition. The coating is generally of Y2O3/Al2O3, although other material combinations can be used. Also, a multi-layered coating can be formed, such that an intermediate coating layer can be formed using standard plasma spray, and a top coating can be formed using PEPVD. The entire ESC assembly can be “packaged” by the coating.

Abstract: A management apparatus is described of a rotating motor and a load during power loss; the apparatus comprises a first switching circuit coupled with the rotating motor and a controller of said first switching circuit. The controller is configured to drive the first switching circuit so as to convert a back-electromotive force voltage developed in the rotating motor into a power supply voltage for the load. The first switching circuit is driven in accordance with a first duty cycle. The apparatus comprises a second switching circuit coupled with the load and driven in accordance with a second duty cycle. The controller is configured to vary said first and said second duty cycles to keep the power supply voltage for the load above or equal to a threshold voltage.

Abstract: Aspects of a method and system for configuring a transformer embedded in a multi-layer integrated circuit package are provided. In this regard, a windings ratio of a transformer embedded in a multi-layer IC package bonded to an IC may be configured, via logic, circuitry, and/or code in the IC, based on signal levels at one or more terminals of the transformer. The transformer may comprise a plurality of inductive loops fabricated in transmission line media. The integrated circuit may be flip-chip bonded to the multi-layer package. The IC may comprise a signal strength indicator enabled to measure signal levels input to or output by the transformer. The windings ratio may be configured via one or more switches in the IC and/or in the multi-layer package. The IC and/or the multi-layer package may comprise ferromagnetic material which may improve magnetic coupling of the transformer.

Abstract: A control device for a travel motor mounted to a vehicle has a resolver which works as a rotation-angle sensor. The control device has a RDC which calculates a rotation-angle output value ? based on rotation detection signals Sa, Sb transferred from the resolver. The control device supplies electric power to the travel motor based on the rotation angle output value ?. The RDC calculates “sin(???)” as an error deviation ? based on the signals Sa and Sb and the rotation-angle output value ?. The RDC calculates an angular acceleration by multiplying the error deviation ? with a gain (=Ka·Kb), and integrates the angular acceleration two times in order to obtain a next rotation-angle output value. A gain control part of the RDC decreases the gain when the judgment means judges that the travel motor rotates at a constant rotation speed.

Abstract: A brushless motor driven by a sensorless driving circuit includes a rotating body capable of being rotated about a center axis; a rotor magnet arranged coaxially with the rotating body; a stator disposed opposite the rotor magnet; and at least one coil wound around the stator. The brushless motor is driven according to a signal containing a third harmonic component relative to a fundamental wave component in an induced electromotive force. Further, an amplitude ratio of the third harmonic component to the fundamental wave component in the induced electromotive force generated in the coil preferably is about 1% or higher.

Abstract: A control device for driving a motor which includes a rotor and a stator is provided. The control device includes a Hall detector and driving circuit. The Hall detector detects magnetic flux variation when the rotor rotates and generates a first detection signal and a second detection signal. The first and second detection signals represent current rotation location when the rotor rotates. The driving circuit generates a driving signal to drive the stator. The driving circuit turns on or off the driving signal according to a control signal and the relationship between the first and second detection signals.

Abstract: The present invention provides a motor drive apparatus which improves a trade-off relation between a stable position detection and noise at its driving. A sensorless drive operation circuit calculates by operation a zero cross point (point p) of a voltage of a position detection phase at the next interval, using time information measured based on an output signal from a comparison circuit at the previous interval and the present interval. After the point p has been calculated, points a and b are detected by interrupting a predetermined time drive current.

Abstract: An apparatus and method for trapping particles in a housing is disclosed. A high voltage terminal/structure is situated within a housing. A conductive material, having a plurality of holes, such as a mesh, is disposed a distance away from an interior surface of the housing, such as the floor of the housing, forming a particle trap. The conductive mesh is biased so that the electrical field within the trap is either non-existent or pushing toward the floor, so as to retain particles within the trap. Additionally, a particle mover, such as a fan or mechanical vibration device, can be used to urge particles into the openings in the mesh. Furthermore, a conditioning phase may be used prior to operating the high voltage terminal, whereby a voltage is applied to the conductive mesh so as to attract particles toward the particle trap.

Abstract: A system is presented for an improved igniter and an igniter bobbin for a high voltage burner igniter that reduces parts count and simplifies assembly of the igniter used in fuel based burners for boilers, forced air furnaces and water heaters. In one aspect of the invention, the igniter bobbin of the present invention comprises two high voltage insulators and a coil bobbin of a high voltage transformer molded or otherwise integrated together into a single monolithic structure. In another aspect, the igniter bobbin may be molded from an insulative material to form the single monolithic structure that insulates the high voltage electrodes which are inserted within the high voltage insulators portion of the structure, and to insulate the primary and secondary coils that are wound onto the coil bobbin portion of the structure.

Abstract: A complex signal processing system for multiple fans is used to control the rotation of a first fan and a second fan. The speed signals of the first fan and the second fan are processed through an XOR operation to obtain a complex speed signal. In response to the complex speed signal, the speed and the operational status of the first fan and the second fan can be evaluated.

Abstract: An autonomous solenoid controller which in its broad aspect includes a microprocessor, a communication bus, and a solenoid driver. The microprocessor includes logic in order to control drivers for at least one solenoid. The communications bus is operably connected to the microprocessor so that the communications bus and the microprocessor communicate with one another. The communication bus communicates with an outside transmission control unit. The solenoid driver is electrically connected between the microprocessor and the solenoid, such that the microprocessor commands the solenoid driver to alter the position of the solenoid.

Abstract: Presented in an apparatus for controlling a brushless DC motor with a permanent magnet arranged on a rotor and a stator with windings. The apparatus includes an observer that is adapted to determine an estimated temperature of the permanent magnet as a function of the temperature of the windings, and determine at least one actuating signal for controlling the DC motor as a function of the estimated temperature of the permanent magnet.

Abstract: An ion generator that can generate a controlled trace amount of ozone together with negative or positive ions. The ion generator includes an insulation substrate, a ground electrode and a high-voltage electrode on the insulation substrate, an insulating film formed on the ground electrode, and a wire electrode. The root of the wire electrode is soldered to the high-voltage electrode. The tip of the wire electrode is arranged so as to protrude in a recessed part. The ground electrode has a pair of legs disposed on the insulation substrate at the sides of the recessed part. The legs are parallel to the wire electrode on opposite sides of the wire electrode. The insulating film is provided on the surface of the ground electrode to cover the ground electrode except the high-voltage electrode contacting a first terminal, a contact portion contacting a second terminal and parts of the legs of tips of the ground electrode that face the tip of the wire electrode.

Abstract: This invention relates to a speed monitor apparatus for monitoring speed and acceleration of rotating turbine equipment (turbomachinery) and for operating an overspeed trip to shut down the equipment in the event that the speed or acceleration exceed predetermined thresholds. The invention provides a speed monitor module having an output switch comprising a plurality of armature clamped relays such that first armatures form a first electrical path only when both first armatures are open or when both first armatures are closed and second armatures provide a second electrical path when either or both second armatures are open or closed such that the second electrical path is discontinuous when either first armature is stuck in an open or closed position causing either second armature to remain floating between an open and closed position.

Abstract: A signage device (10) in which a housing (12) receives a circuit board (30) having a plurality of spaced-apart light sources (38) to define at least one symbol and overlaid by a message plate (42) having a projecting channel (46) with a translucent light emitting side (54) aligned with the light sources and a light blocking overlay sheet (60) defining an open slot (62) configured for mating reception of the projecting channel, whereby light from the light sources communicates from the light emitting surface of the channel extending from the overlay sheet.

Abstract: A glass workpiece being processed in a vacuum plasma processing chamber is dechucked from a monopolar electrostatic chuck by gradually reducing the chucking voltage during processing while maintaining the voltage high enough to clamp the workpiece. A reverse polarity voltage applied to the chuck at the end of processing assists in dechucking. The workpiece temperature is maintained at a high value at the end of processing to assisting in dechucking. Peak current flowing through the chuck during lifting of the workpiece from the chuck controls the amplitude and/or duration of the reverse polarity voltage during the next dechucking operation.

Abstract: The present invention relates to an active magnetic field sensor, in particular a wheel bearing sensor unit, comprising at least one magnetic sensor element (10, 21, 36) for converting a temporally periodic magnetic field into a temporally periodic electric sensor signal at signal outputs (37, 31) and an electronic signal-evaluating circuit, the said magnetic field sensor being electrically fed by way of a sensor interface, wherein an active electric processing of periodic signals (38, 39) of the magnetic sensor element is performed in two or more separate signal channels of the evaluating circuit respectively associated with the sensor signals.

Abstract: The invention is based on a system for changing a signal representing rotational motion in a motor vehicle with first means for generating a first signal representing the rotational motion and a second means for generating at least one second signal representing additional information (direction of rotation, air gap, and/or brake lining wear). In addition, a third means is provided, by means of which the first signal (rotational speed signal) can be changed as a function of the second signal (direction of rotation, air gap, and/or brake lining wear). The essence of the invention is that the first means is designed in such a way that the first signal (rotational speed signal) assumes at least two first current values and/or two first voltage values.

Abstract: A method for accurately estimating the rotational speed of a machine includes the steps of initializing a counter, measuring a position of the machine, incrementing the counter, waiting for a position update, measuring a next position of the machine, calculating a difference between the position measurement, measuring the amount of time elapse between positions, returning to the step of incrementing to the counter if the difference is less than a predetermined amount, returning to the step of incrementing the counter if the amount of time is less than a predetermined time, dividing the difference by the amount of time to determine the estimated rotational speed of the machine, and outputing the estimated rotational speed of the machine.

Abstract: A vehicle wheel speed sensor has a rotor 11 provided with a series of circumferentially spaced rotor elements 12 mounted on a wheel axle 10. A sensor 13 mounted on a relatively non-rotatable support is influenced by passage of the rotor elements to output a sine wave signal. The sine wave signal is fed for processing to an interface unit 15 on the vehicle and pulses are generated at at least two predetermined phases of each cycle of the sine wave. A method of producing marker pulses by detecting the zero cross-over points and the peaks and troughs of a sine wave signal, and generating a marker pulse at each zero cross-over point and at each peak and trough of the sine wave signal is also described.

Abstract: A speed and phase sensor counterrotates aircraft propellers. A toothed wheel is attached to each propeller, and the teeth trigger a sensor as they pass, producing a sequence of signals. From the sequence of signals, rotational speed of each propeller is computer based on time intervals between successive signals. The speed can be computed several times during one revolution, thus giving speed information which is highly up-to-date. Given that spacing between teeth may not be uniform, the signals produced may be nonuniform in time. Error coefficients are derived to correct for nonuniformities in the resulting signals, thus allowing accurate speed to be computed despite the spacing nonuniformities. Phase can be viewed as the relative rotational position of one propeller with respect to the other, but measured at a fixed time. Phase is computed from the signals.

Abstract: An idling system is disclosed for devices such as internal combustion engines having a speed controlling or governor. When no load is sensed by a load sensing means, a disable means generates a disable signal to deactivate the engine's speed controller after a predetermined time delay period. When a load is sensed, the disable means is itself disabled, allowing the device's speed control means to operate the device at the higher governed speed.

Abstract: Known rotational signal generators for generating signals that correspond to the rotational speed and/or the angle of rotation of a rotatable component part may be connected with the rotatable component part, by means of a coupling or the like. This coupling results in higher space requirements and in an expensive assembly of the rotational signal generator. The rotational signal generator according to the invention is equipped with a hollow shaft and can be fitted onto the rotatable component part. For the compensation of misalignments or the like of the rotatable component part, the rotational signal generator is mounted elastically. The rotational signal generator may be used for measuring the rotational speed, for measuring the angle of rotation, for measuring the length and for similar operations in the fields of driving technology, systems construction, automatization technology and the like.

Abstract: A system and method determines the rotational speed of a rotating member by determining speed from signals having a frequency directly proportional to the rotational speed. The system provides for the estimation of rotational speed even if no speed signals are detected over a sampling interval.

Abstract: A vehicle speed detecting device utilizes two vehicle speed pulse generators, a vehicle speed memory device, pulse counters, abnormality detectors, pulse signal transfer devices and an alarm device which are all integrated into the electronic control circuit of a micro-processor through two sets of signal processing devices. The detecting device not only indicates the speed of the vehicle but also detects abnormalities in either of the vehicle speed pulse generators and provides an appropriate alarm.

Abstract: Automatic guided vehicles require an accurate method and apparatus for determining vehicle velocity. The subject apparatus is associated with a vehicle having at least one surface engaging idler wheel. A resolver produces a rotation angle rate signal having a value responsive to the angular rotation rate of the idler wheel. A resolver-to-digital converter receives the rotation rate angle signal and produces a rotation rate pulse signal. A clock substantially continuously produces clock pulse signals having a predetermined frequency. A counter receives the rotation rate pulse signal and the clock pulse signal and controllably produces a time signal corresponding to the number of clock pulses received over the duration of a predetermined portion of the rotation rate pulse signal. A logic device controllably receives the time signal and produces a vehicle velocity signal.

Abstract: A method and apparatus for detecting a failure in the speed sensing system of a rotating shaft prime mover. The control system for the rotating shaft prime mover includes a speed sensing system for measuring the rotational speed of the shaft, a speed feedback system for providing actual rotational speed, and a monitoring system for monitoring the speed sensing system. The monitoring system detects loss of speed signal and overspeed conditions. The speed pickup sensing system includes at least a first, second and third speed sensor. The monitoring system senses with the speed pickup sensors the rotational speed of the shaft to provide signals representative thereof. It selects between the first and second speed signal the signal representative of the actual rotational shaft speed to produce a primary speed signal. The system compares the primary speed signal to the third speed signal for producing a speed feedback fault signal when the primary signal deviates from the third signal by a predetermined value.

Abstract: An automatic speed control system comprises a bistable device, a coincidence gate and a monitor circuit which monitors the speed control element of an engine and applies a first input signal to the coincidence gate if malfunction occurs in the speed control element. The coincidence gate provides a reset signal to the bistable device when it simultaneously receives a second input signal from a microprocessor. The microprocessor verifies the operating conditions of the bistable device before the system is switched to automatic mode and sets the bistable device into a condition for receiving the reset signal from the coincidence gate. During automatic control mode, the microprocessor constantly checks the bistable device if it turns to the reset condition while controlling the speed control element. Whenever the microprocessor detects a reset condition in the bistable device, it enables the speed control element to allow the engine to be controlled on manual mode.

Abstract: In a vehicular power steering system, the hydraulic fluid supply to a hydraulic power actuator is controlled in accordance with the vehicle speed and the angular velocity of the steering wheel. Preferably, the fluid supply is reduced so that the steering effort becomes heavier as the vehicle speed increases while the fluid supply is increased when the angular velocity of the steering wheel is high. To control the fluid supply, there is provided, in a power steering system, a bypass valve means for draining a portion of the fluid flow to bypass the power actuator, and control means for producing a control signal to control the bypass valve means in accordance with the vehicle speed and the angular velocity of the steering wheel.

Abstract: In an idling controller, particularly for automotive vehicles, there are present both a control amplifier with integral time portion (3) and a limiter (6) with proportional time portion. The inputs of the limiter are acted on by the correcting variable from the output of the control amplifier and by a limiter reference variable formed with the actual-speed value. The output of the limiter is fed back to an input of the control amplifier. In order to obtain the desired time action of the idling controller upon sudden drops in speed, at least one time member (12) with differential time portion is provided between the input (1) of the actual-speed value and the output of the limiter (6). The limiter (6) is so dimensioned and coupled with the output of the control amplifier (3) that, upon a drop in speed beyond a predetermined value, the correcting value (y) is controlled by the output variable of the limiter (6) (control limit).

Abstract: A variable reluctance transducer includes a C-shaped assembly defining a magnetic circuit, one limb of the C being longer than the other. The assembly is arranged with its limbs on opposite sides of a movable member. A winding linked to the magnetic circuit is connected to a discriminating circuit including an integrator having a variable bias circuit which ensures that the peaks of the integrator output are in a predetermined relationship to a reference voltage. A comparator compares the integrator output with the reference voltage.

Abstract: An acceleration sensor acts on the variable-frequency pulses of a speed sensor signal to recognize any variation of the pulse period thereof and to produce an output indicative of the magnitude of the detected variation to within a fixed degree of accuracy. The periods of groups of known, variable number pulse groups are measured with reference to a fixed-frequency clock pulse signal and the measurement periods of successive groups of equal numbers of pulses are compared. If the difference between pulse group periods is zero or less than a predetermined value, the number of pulses in each group is increased in order to increase the total number of clock pulses during the measurement interval. The number of pulses per group is increased until the difference between measured periods exceeds the predetermined value or until the number of pulses per group reaches a predetermined maximum.

Abstract: An automatic speed control system is disclosed in which an error signal Ve, representing the speed error of the vehicle, is added to a ramp voltage, ramping between fixed values, to produce a control signal Vc. Two comparators compare Vc with upper and lower limits, respectively, so as to produce a pulse train on one of two lines depending on the sign of the error and having a mark-space ratio depending on the magnitude of the error. A circuit responds to the first pulse to occur in the pulse train from one of the two comparators when the vehicle is accelerating towards and overshooting a new desired speed and, via a switching circuit, lowers the upper limit applied to that comparator so as to lengthen the first pulses and help to reduce overshoot of the desired speed. When the vehicle ceases accelerating, the upper limit is switched back to the desired value, and is also switched back to its original setting when the speed falls by a preset amount.

Abstract: A vehicle speed system is described in which an electrical signal representing actual vehicle speed is compared with a stored signal representing desired vehicle speed. Any speed error is used in a servo loop to generate a control signal which tends to reduce the error to zero. In addition, signals representing the actual and desired vehicle speeds are compared in a comparator unit so as to produce a disabling signal when the actual vehicle speed either exceeds the desired speed by more than a predetermined amount, or falls below the desired speed by more than a predetermined amount, (e.g. because road conditions prevent the vehicle engine from driving the vehicle at or close to the desired speed). This enabling signal is used to switch the control system out of operation.

Abstract: An automatic speed control device for a vehicle or a stationary generator for emergency use is disclosed.

Abstract: The invention relates to a device for measuring the angular position of a gear in a digital ignition system of an internal combustion engine, wherein an origin sensor responsive to the passage by of a pre-set tooth of a gear, is connected to one of inputs of a pulse former having a second input to which an output of a rectifier and filter circuit is connected; and an input of the rectifier and filter circuit is coupled to the output of an angle pulse sensor.

Abstract: In order to prevent ignition power losses at low engine speeds and further to provide for the use of ignition control signals of both unipolar and bipolar nature, the invention provides that a Schmitt trigger which generates the principal ignition control signal is actuated by the transducer. The switching thresholds of this Schmitt trigger are changeable by a secondary threshold recognition circuit which can shift at least the negative threshold of the principal threshold circuit to more positive values. The invention also includes a delay circuit which prevents the return of the shifted threshold to more negative values. Still further included is a third threshold circuit which is engaged only at some higher engine speed.

Abstract: To counteract the phase error in the signal from an rpm transducer of an engine test stand or analyzer at varying engine speeds, the signal processor of the invention receives the transducer signal whose amplitude varies with frequency and generates therefrom an output signal of constant amplitude. This signal is supplied to a threshold switch which includes circuitry for integrating periodic output signals and generating therefrom a control signal whose amplitude is proportional to the frequency of the input signal. This analog signal is used to alter the switching threshold of the threshold switch, thereby imparting to the output signal a frequency compensation which counteracts the inherent phase error and results in an output signal of constant phase with respect to the transducer signal. The apparatus of the invention is particularly useful for adjusting ignition timing, valve timing, etc. in internal combustion engines in which the input signal is derived from the crankshaft speed.

Abstract: The disclosure sets forth trip circuitry for a rotating shaft machine which includes redundant overspeed protection and means for testing the overspeed protection circuit while the machine remains in operation. Moreover, further protective circuitry is provided for detecting a failure in the speed sensing system. The overspeed protection and the speed sensing failure circuit are each connected to a relay system which may actuate a trip servo valve to a closed position.

Abstract: A trailer brake control system which includes a variable frequency oscillator, an electromagnetic inertial sensor adapted to detect either lateral acceleration or longitudinal deceleration of a trailer and to vary the output frequency of the oscillator in accordance therewith, and a circuit for applying trailer brakes as a function of such frequency variation either to correct a trailer sway condition indicated by lateral trailer acceleration or when tractor brakes have been applied as indicated by longitudinal deceleration of the tractor/trailer combination.

Abstract: There is disclosed a control circuit which provides a control signal for initiating operation of a glue applicator to cause the applicator to apply glue to a predetermined area on an article moving past the applicator, which circuit automatically compensates for variations in the speed of the article.

Abstract: The manufacture of a tachometer of a type having annularly arranged tachometer markings on a rotary tachometer device includes the steps of rotating the tachometer device. A signal is generated having recurring signal portions for providing tachometer markings upon recordation on the rotary tachometer device. The number of signal portions occurring in the latter signal durin a revolution of the rotating tachometer device is adapted to a whole number of tachometer markings accommodable on the tachometer device in a continuous circular array. The signal having the mentioned adapted number of signal portions is recorded onto the rotating tachometer device to provide the tachometer markings in a continuous circular array.

Abstract: An alarm system is disclosed for generating alarms when torsional oscillations of a rotating shaft exceed predetermined limits and fail to subside at a predetermined rate. The alarm system receives a torsional oscillation input signal developed by measuring the deviation of instantaneous shaft angle from a uniformly increasing value. The input signal is converted to a direct current torsional oscillation signal representative of the magnitude of oscillation. The torsional oscillation signal is compared against a first adjustable reference voltage representative of a first maximum magnitude of oscillation. A low level alarm signal is generated when the oscillation signal exceeds the first reference voltage for a predetermined length of time. The oscillation signal is also compared against a second reference voltage representative of a second maximum magnitude of oscillation. An output signal is generated when the oscillation signal exceeds the second reference voltage.

Abstract: A control system for a laundry machine generates a control signal to operate a door lock unit and prevent the door from opening while the laundry machine cylinder is rotating. A permanent magnet is mounted adjacent to the drive wheel of the cylinder so that the wheel spokes cut through the magnetic field of the magnet. A pick-up coil is mounted coaxial with the magnet and generates an induced pulse signal as the wheel turns. The induced pulse signal is processed by circuitry mounted on a printed circuit board to generate a DC control signal for the door unlocking circuitry of the door lock unit. The pulse signal is rectified and smoothed to provide a DC signal and is processed by a timer circuit to provide an amplified, precise switching signal which is used as the control signal. The DC control signal operates an electronic switch which connects an AC power source across a relay coil to open the door unlocking circuit so that the door remains locked as long as the DC control signal is generated.