Abstract: An information handling system may detect fan blockage for one or more fans using a target value such as the rotational rate of a fan or a duty cycle value of the pulse width modulation (PWM) signal for a fan, and a monitored value includes at least the other one of the rotational rate of the fan or the duty cycle value of the PWM signal for the fan. The information handling system may determine whether either the duty cycle value of the PWM signal for a fan or the rotational rate of the fan meets or crosses a threshold value. The threshold value, for example, may include an intake blocking warning limit or a rotational rate limit. The information handling system may then generate a notification to the user, such as a re-positioning notification. The methods described or illustrated may be entirely implemented in an embedded controller.

Abstract: A signal is outputted via a transmission path with little attenuation while eliminating high-frequency noise. A current sensor includes: a coil wound around a magnetic core through whose interior a measured electrical path is inserted, is connected to ground at one end, and outputs a current with a current value in keeping with a current value of a measured current flowing on the measured electrical path; a constant impedance filter whose input terminal is connected to another end of the coil, limits a frequency range of the current inputted from the input terminal to a desired frequency range, and outputs the detection current from an output terminal; a transmission path that is directly connected at one end to the output terminal; and a terminating resistance that is connected between another end of the transmission path and ground and converts the current flowing via the transmission path to a detection voltage.

Abstract: A flow measuring device for measuring flow of a fluid. A housing has a passage which extends between an inlet and an outlet. A shaft is disposed within the housing and is rotatable about a central axis. A flow detector is mounted on the shaft and disposed at least partially within the passage. The flow detector includes a rotatable, generally cylindrical body that rotates about a central axis as the fluid flows. A magnet is mounted on the rotatable body or on the shaft, and is configured to rotate simultaneously with the body about the central axis. A sensor is disposed within the housing and configured to sense rotation of the magnet as the flow detector angularly displaces about the central axis so as to detect angular displacement of the flow detector.

Abstract: A slip-ring unit for transmitting an electric current includes a first component group and a second component group arranged in a manner allowing rotation relative to each other. The slip-ring unit has a first track and a second track, a brush and a slip ring contacting each other over different rotational positions along one of the tracks. The first component group has a first connection terminal and an electric circuit for monitoring conditions, while the second component group has a second connection terminal The electric current is transmittable from the first connection terminal to the second connection terminal over the first track, and an electric voltage is transmittable over the second track to the circuit. The slip-ring unit is configured such that the first track and the second track are connected electrically.

Abstract: A control system for use in safety critical human/machine control interfaces is described, more particularly a joystick type control system and particularly a joystick type control system utilizing magnetic positional sensing. The control system provides a control input device having a movable magnet, a pole-piece frame arrangement positioned about the magnet, at least three magnetic flux sensors being positioned in said pole-piece frame arrangement and a monitoring arrangement for monitoring the output signal of each of said at least three sensors.

Abstract: An angular position sensor and method that relies on a stationary circular array of Hall sensors and a rotatable circular array of magnets arranged about a common axis. A periodic and simultaneous reading of all of the Hall sensor outputs is used to determine angular velocity.

Abstract: A display unit, attached to a bar forming a handlebar, frame or stem of a bicycle with a securing tool, comprises a body having a display part capable of realizing a first display state displaying first data (traveling speed, for example) and a second state displaying second data (traveling distance, for example). The first and second display states are switched by pressing down body from above.

Abstract: A circuit is arranged to pulse-width modulate the duty cycle of a power supply signal that is used to control the rotational speed of a fan in a temperature-controlled system. The control system includes an edge detector for monitoring a tachometer signal that is provided by the fan. The tachometer signal is monitored at a rate (e.g., one Hertz) that is substantially lower than the rotational speed of the fan. The control system also includes a timer for recording time intervals between selected edges of a monitored tachometer signal. The fan speed is determined from the recorded time intervals. The control system extends the duty cycle of the pulse-width modulated signal to ensure that the fan power remains stable over the period in which the tachometer signal is to be monitored. Maintaining fan power ensures the validity of the tachometer signal during the period that the fan power is maintained.

Abstract: A sensor retainer for a bicycle sprocket assembly includes an annular member for mounting and rotating coaxially with the bicycle sprocket assembly and a sensor element fixed to the annular member. Alternatively, the sensor retainer may include a fixing member for mounting a derailleur or other transmission to a bicycle frame and a sensor element mounted to the fixing member.

Abstract: An operating circuit (1) for controlling the speed of a cooling fan motor (3) for computer cabinetry (7), and for determining an under-speed condition in the fan motor (3) comprises a control circuit (15) which controls a variable output signal generator circuit (18) for outputting a pulse width modulated signal corresponding to the desired fan speed for switching a switching circuit (8) in a power supply circuit of the fan motor (3) for pulse width modulating the power supply to the fan motor (3). A monitoring resistor (R1), a capacitor (C1) and a circuit (12) provides a tachometer signal to the operating circuit (1). A gate circuit (22) gates the second and fourth pulses of the tachometer signal to a counter (20) which counts clock pulses from a clock signal generating circuit (19) between the rising edges of the second and fourth pulses which are in turn stored in a register (23) for comparison with a reference count by a comparator (25).

Abstract: In the present invention, a detection coil and a cancellation coil are closely provided and electrically connected in series to cancel induction noise. The cancellation coil may be disposed at a position not to sense the rotation. An axis of the cancellation coil may be provided in parallel to an axis of the detection coil. The numbers of turns for the cancellation coil may be the same as those for the detection coils. The cancellation coil may be disposed coaxial to the detection coils.

Abstract: A method and a device for detecting rotational speed with an inductive sensor in which a sinusoidal potential is induced by a magnet wheel and then fed to a filter with a comparator connected downstream of the filter and therefrom into a square-wave signal that is essentially proportional to the rotational speed of the magnet wheel. This output signal of the comparator is evaluated in a microcomputer. In this evaluation, only the same type of edges of the comparator signal are evaluated, specifically those in which the intervals fluctuate less when considered over a certain time span. The microcomputer here can initially evaluate both types of edges, that is, positive and negative edges, and then use those edges in which smaller fluctuations, that is, interference, are determined for calculating the rotational speed. The microcomputer can also first evaluate only one type of edges and change over to edges of the other type only if the former displays interference above a present value.

Abstract: A battery-powered rotation detector detects passing of a rotating magnet attached to a vehicle wheel to generate and transmit a rotation signal. A receiver receives the rotation signal. A processor computes the vehicle running condition (e.g., speed, traveled distance) from the received rotation signal and displays the results on a display device. The processor monitors intervals between the rotation signals to detect when the vehicle is stopped. When the vehicle is stopped, the processor disconnects a battery power supply from components such as the display device for power savings. In addition, the processor checks the strength of the received rotation signal to determine a capacity of the battery in the rotation detector, and operatively indicates a power failure of the rotation detector.

Abstract: A shaft speed signal indicator including a hub, bearing, switch assembly and housing which are mounted as a compact and integral unit to a free end of a revoluble shaft. The signal indicator further includes electric circuitry connected to contacts of the switch assembly for signalling the rotational speed of the revoluble shaft relative to a predetermined revolution rate. The hub carries a plurality of magnets for rotation about a predetermined path and to cause the contacts of the switch assembly to operate at a rate proportional to the movement of the magnets therepast. The housing of the signal indicator maintains the contacts of the switch assembly at a predetermined distance from the magnets and includes an exterior configuration substantially encompassing the hub and shields the end of the revoluble shaft.

Abstract: A device for evaluating periodic signals from inductive pick-ups compensates for the lag of the pick-up signal. This lag increases with increasing frequency as a consequence of the inductance of the pick-up, with respect to the position of a movable part that is to be scanned by the said pick-up. The relative time shift in the evaluation edge of the pick-up signal, which is phase-compensated via the frequency, is compensated for via changes in the amplitude of the pick-up signal.

Abstract: A pulse control circuit generates latch signals in response to edges of externally-input pulses and generates a resetting signal after each of the latch signals is generated. A pulse position measurement counter counts reference clock signals, thereby measuring the time interval between the generation of one latch signal and the generation of the succeeding latch signal. In response to the latch signal, a latch circuit latches the time interval measured by the pulse position measurement counter as output data. A pulse detector detects that the time interval between successive latch signals is shorter than a predetermined time. It also detects that the number of latch signals which have been input is larger than a predetermined number. A data control circuit is employed in association with the pulse detector.

Abstract: A wireless data display system has a receiver/display unit tuned to the same frequency as a sensor/transmitter unit for monitoring wheel rotation for a vehicle such as a bicycle. The two units are preferably battery powered, and their circuits are designed for low power consumption. Both units have directed antennas positioned in alignment with each other. The receiver includes a tunable antenna to enhance signal reception and reduce sensitivity to a transmitter of an adjacent system, as well as filter and latch circuitry to reduce interference from EMI or RFI or from adjacent operation of a similar transmitter/receiver pair.

Abstract: A sensor is connectable with a load circuit via two conductors. The sensor receives its electrical power from the load circuit via the two conductors and similarly provides its output signal indicative of the sensed phenomenon via the same conductors. An unregulated source potential is provided to a terminal of the sensor from a supply potential via the load circuit. Voltage regulating circuitry in the sensor converts the unregulated source potential to a regulated operating potential for its active circuit elements. Certain output circuitry in the sensor is connected to the terminal having the unregulated source potential for conveying an output signal from the sensor to the load circuit.

Abstract: In a method for measuring vehicle speed, initial vehicle speed measurement after a vehicle speed measurement power supply is turned on, is based on the predicted number of pulses to occur during a time interim which is in turn based on a period of a single pulse generated by a vehicle speed signal. After a predetermined time interval has passed, vehicle speed measurement is based on the actual number of pulses generated by vehicle speed signals during that time interval.

Abstract: An air-core gauge comprising two coils in quadrature has a driving system with switches on a junction terminal and end terminals of the two coils, and a drive circuit controlling the switches so that each terminal is selectively at either of two signal levels, with one terminal being connected alternately to the two signal levels with variable duty cycle depending upon the angle through which the pointer of the gauge is to be turned. For any given angle, one terminal is held at one level, another at the other level and the third is alternated between the two levels with appropriate duty cycle. Any angle of pointer deflection from 0.degree.-360.degree. can be achieved with just the two voltage levels and calculating the duty cycle from an appropriate function of tangent values of angles in the range 0.degree. to 45.degree..

Abstract: In an electronic watch, a sensor of the closed type which consists of an upper circular cover (10), a shell (20), a rotary turning disk (30), clamped between the upper cover and shell, the shell having a socket (23) on one side, a reed switch (50) enclosed in the socket, the turning disk forming a concave through (31), a pair of magnets (40) located laterally in the concave trough, an axial shaft, the shell having a first central orifice (21), the axial shaft being held in the orifice, a plier (32) extending from the side of the turning disk, the upper cover having a pair of lugs, the shell having a pair of second orifices on each side of the central first orifice (21), the lugs penetrating the second orifices, an external axial wheel, the plier (32) engaging the axial wheel.

Abstract: A pulse length indicator, for signaling when the length of a pulse from a cyclic signal source has exceeded a chosen duration, has a ramp signal generator, coupled to the cyclic signal source, which produces a ramp signal. The level of the ramp signal is dependent upon the duration of either of the high and low levels of the cyclic signal. The ramp signal is fed to a level sensitive switch which couples an indicator, typically an LED, to a power source. When the level of the ramp signal is sufficiently long or short, the switch closes to actuate the indicator. The ramp signal generator can be a simple R-C circuit with the signal source being AC or DC coupled to the switch.

Abstract: Speed detectors are provided for detecting speeds of each of the four wheels of a vehicle. An electric circuit is provided to compare the speeds of all wheels and to turn on at least one lamp when a difference between individual wheel speeds is detected, whereby slipping of wheels is indicated.

Abstract: A low offset position demodulator that may be used in the positioning servo of a disk drive or similar device. A first stage of the demodulator circuit multiplies or switches a servo carrier signal, modulated with position information, with a synchronized gate signal. This first stage of the demodulator circuit includes a differential output and means for controlling the common mode operating point thereof with an external control voltage. A low pass filter, also having a differential output, is coupled to the differential output of the first stage of the demodulator. A differential-to-single-ended conversion stage is tied to the low pass filter output to provide a single position output signal. Also coupled to the low pass filter differential output is an averaging network that averages the signal appearing on one of the two differential signal lines with the signal appearing on the other differential signal line.

Abstract: An object displacement sensor specifically adapted for high speed counting of passing nonmagnetic objects is disclosed which has a resonant circuit made up of at least one inductive element 2 and a condensor whose one plate consists of a conductive surface 3 and whose other plate is successively formed by each object 4 passing close to this surface 3. The resonant circuit is connected to a first oscillator 6 which determines the functioning frequency such that the signal issued from the first oscillator 6 is modulated in frequency to the rhythm of the passage of the objects 4.

Abstract: Apparatus operable by the player of a video or electronic game to generate pulses at a rate proportional to the speed of rotation of a rotatable member by closing one of a pair of switches dependent upon the direction of rotation. One of the switches is monitored to determine the direction of rotation. The generated pulses are counted per unit time to provide a velocity signal.

Abstract: This specification discloses an apparatus and method for providing electrically distinguishable signals occurring as a function of the position of a moving element. The electrical signals are generated by a piezoelectric apparatus and can be used to determine a variable such as revolutions per minute of the movable element. Particular ones of the electrically distinguishable signals can be used for initiating a function such as the firing of the spark plugs.

Abstract: A tachometer comprises a magnet having north and south magnetic poles and a magnetically operated switch for sensing movement of the magnet and for producing an output signal in response thereto. The magnet is supported on one end of a shaft which is supported for rotation in a bearing. The other end of the shaft is threaded into the rotating member, the output of which is to be measured. The bearing is mounted on a plate so that the plate and shaft are independently movable. The switch is mounted on the plate in proximity to the magnet to detect movement of the magnet. The frequency of the output signals produced by the switch indicates the rate of rotation of the rotating member.

Abstract: A speedometer/odometer system for use on a bicycle which system uses a magnet/coil arrangement and a signal processing means for providing a count of the spokes of a wheel as they pass the magnet/coil arrangement the count being determined over a selected time period to provide a digital signal speed indication or being cumulatively counted to provide a digital signal indication of distance travelled. The system can be easily calibrated by using means for producing a calibration constant which can be used to multiply the digital signals and the resultant signal supplied to a suitable digital display means for visually displaying the speed or distance for the rider.

Abstract: An apparatus for obtaining a signal relative to rotational speed of a rotary element is disclosed. The apparatus comprises a permanent magnet and a magnetic body which relatively approaches or moves away from the permanent magnet according to the rotational speed of a rotary member. A magneto-sensitive switch is operated in response to the change in intensity of the magnetic field produced by the relative motion between the permanent magnet and the magnetic body. Therefore, there can be obtained an apparatus which is small in size and high reliability.

Abstract: Input variables are varied cyclically and sequentially in the same direction until the sign of the differential quotient of the magnitude of the error with respect to time changes.

Abstract: A belt movement sensor detects the movement of a belt having signal generating means embedded in or emplaced on the surface of a drive belt, and actuates a warning signal and/or controls the drive motor when the signal from the sensor varies by more than a pre-determined amount from a set point.

Abstract: A multi-function device using two ICs, with the precision ignition pulse frequency-to-voltage converted signal produced in the RPM portion being used as input to both ICs. Chatter pulses produced by an operational amplifier in the RPM limiter are utilized to shunt ignition pulses to ground in a proportional manner as engine speed approaches the selected maximum.

Abstract: Distance-measuring apparatus for attachment to a speedometer cable comprising a sensing assembly and a digital counter; the sensing assembly including a drum portion having a bore therethrough for disposition over an exposed section of the rotatable inner shaft of the speedometer cable, fasteners associated with the drum portion to secure the drum portion to the inner shaft, at least one magnet affixed to the drum portion adjacent a point on the periphery thereof, a housing surrounding the drum portion and spaced therefrom to allow independent rotation of the drum portion therein, fasteners associated with the housing to secure the housing to spaced ends of the sheath of the speedometer cable adjacent to the exposed section of the inner shaft, a magnet-responsive switch affixed adjacent a point on the periphery of the housing; electrical leads connecting the switch with the digital counter; the digital counter being capable of receiving and retaining a preselected constant value and adding the constant value

Abstract: A shaft speed and hot bearing indicating apparatus is described having a transducer actuating means mounted on the shaft immediately adjacent the supporting bearing for actuating an electrical transducer to produce an electrical pulse as the transducer actuating means is rotated during each revolution of the shaft. The transducer pulse is processed by an electronic mechanism for multiplying the transducer pulse by sixty by a phase-locked loop network and then counting the number of multiplied pulses occurring during each one second of time interval in a BCD counting mechanism. The total count is displayed each second on a decimal digital display. The apparatus also has means for activating an alarm when the sensed speed falls below a preset speed. The transducer activating means is responsive to the temperature of the bearing and is rendered ineffective when a preset temperature is reached.

Abstract: An electronic odometer and speedometer for bicycles computes distance and speed based upon input signals generated by interruption of a light beam by each spoke and the valve stem of a wheel of the bicycle. The interruption time of the light beam caused by the valve stem is substantially greater than that caused by the spokes; accordingly, it is readily detectable and the signal produced may be treated as a reference signal upon which the computations are based and the signals generated by the spokes provide a continuous real time update. Alternatively, the number of interruptions of the light beam per time, may be employed to compute the speed and the aggregate period of the number of interruptions may be employed to compute the distance. The light signal generating and detaching elements have non-movable parts and are mounted upon the frame of the bicycle without interfering with the normal removal and mounting of the wheel.

Abstract: An arrangement for use in indicating the speed of rotation of a body including a switch operated by elements which rotate according to the rotation of the body, a frequency generator which has an output signal at a frequency related to the desired speed of rotation of the body and an indicator which is actuated in accordance with the signals from both the switch and the frequency generator.

Abstract: A device for detecting the opening of a throttle valve of a diesel engine for vehicles. The device comprises a magnetic shield adapted to be rotated responsive to the opening of the throttle valve, a magnet adapted to be inserted into the magnetic shield, a plurality of reed switches embedded in the housing, and a plurality of flip-flop circuits adapted to be set or reset for producing a gate signal to be fed to a gate circuit.