Abstract: A self-calibrating integrated circuit includes a processor having at least one analog function used with the processor; one or more sensors adapted to sense one or more environmental parameters of the at least one analog function; and a solid state memory being configured to store the one or more environmental parameters of the at least one analog function.

Abstract: An improved two loop capacitive sensor oscillator circuit converts a transducer capacitance to a frequency and includes a first loop to create an oscillatory waveform having a frequency related to a capacitance of the capacitive transducer. The first loop includes a resistor. The resistor is electrically coupled to a capacitor. The resistor is also electrically coupled to the capacitive transducer. The capacitive transducer is electrically coupled to an input of a first inverter gate. A second loop oscillates at the frequency of the first loop and further generates a second waveform of a substantially square wave shape at the same frequency. The second loop is electrically coupled to the first loop and the output of a third inverter gate is substantially a square wave at the frequency related to the capacitance of the capacitive transducer.

Abstract: An oscillator and a method for producing an improved oscillator that will generate an accurate frequency when encountering a vibration. The oscillator and method uses a crystal with minimal cross-axis coupling. Further, a first accelerometer produced using MEMS technology is used. The first accelerometer is positioned inside of the oscillator so that the accelerometer accurately measures any vibration encountered by the oscillator. The first accelerometer and the crystal are maintained at constant temperature to minimize phase shifts and gain variations.

Abstract: A clock oscillator embedded in an integrated circuit, including a piezoelectric resonator formed on the integrated circuit; a clock generator coupled to the on-chip piezoelectric resonator, one or more sensors adapted to sense one or more environmental parameters affecting the piezoelectric resonator; and a processor coupled to the clock generator and the one or more sensors to adjust the frequency of the clock generator based on the one or more environmental parameters.

Abstract: A weighing apparatus includes a SAW oscillator and a “push oscillator” to force the SAW oscillator into a desired mode of operation. A SAW temperature oscillator and a thermistor are also provided. The frequency of the “push oscillator” is made immune to temperature changes by generating it via a mixer mixing the SAW temperature oscillator with an adjustable fixed frequency oscillator. Long term stability of the SAW temperature oscillator is achieved by periodic calibration with the thermistor.

Abstract: A system of contactless electromagnetic transmission between a terminal including a series oscillating circuit for generating an electromagnetic field and a transponder including a parallel oscillating circuit, these oscillating circuits being sized so that the coupling coefficient between them rapidly decreases when the distance separating the transponder from the terminal becomes smaller than a predetermined value.

Abstract: In one embodiment, a magnetometer includes an electromechanical resonator coupled to a drive-and-detect (DD) circuit. The resonator has a deformable beam that is a part of a closed current path. By applying a periodic drive signal to a drive electrode located in proximity to the deformable beam, the DD circuit induces an oscillation of the beam. In the presence of a magnetic field, this oscillation changes the magnetic flux through the closed current path, thereby generating an oscillating electrical current in the path. Dissipation of this current due to resistive losses in the closed current path then dampens the oscillation of the deformable beam with a damping coefficient that depends on the magnetic-field strength. Using a sense electrode located in proximity to the deformable beam, the DD circuit detects the oscillation amplitude. Based on the detected amplitude, the DD circuit changes the frequency of the drive signal to find the resonant frequency.

Abstract: A self-calibrating integrated circuit includes a processor having at least one analog function used with the processor; one or more sensors adapted to sense one or more environmental parameters of the at least one analog function; and a solid state memory being configured to store the one or more environmental parameters of the at least one analog function.

Abstract: A reference timing signal apparatus with a phase-locked loop (PLL) has a computer algorithm which adaptively models the multiple frequencies of an oscillator following a training period. The oscillator is part of a PLL and the oscillation frequency thereof is controlled in response to the phase detector output. The computer algorithm processes the control signal applied to the oscillator. The computer algorithm updates the characteristics of the model relating to the aging and temperature of the oscillator, using for example, a Kalman filter as an adaptive filter, in accordance with a cumulative phase error in the PLL calculated during a given time interval. By the algorithm, the subsequent model predicts the future frequency state of the oscillator on which it was trained. The predicted frequency of the model functions as a reference to correct the frequency of the oscillator in the event that no input reference timing signal is available.

Abstract: A sensing system includes a ring oscillator that emits electromagnetic radiation at a characteristic frequency. The ring oscillator comprises an odd number plurality of inverters that are electrically connected in series. The sensing system also comprises a temperature stabilized voltage source that is used to supply voltage to the inverters of the ring oscillator. A sensing load for sensing a change in a preselected environmental condition is operably connected to the ring oscillator. When the load senses the preselected environmental condition, the sensing load alters the characteristic frequency of the ring oscillator and hence the electromagnetic radiation as emitted by the ring oscillator. A pick-up antenna receives the electromagnetic radiation as emitted by the ring oscillator and detection electronics, operably coupled to the pick-up antenna, measure the frequency of the electromagnetic radiation as received by the pick-up antenna.

Abstract: According to some embodiments, a clock signal having an adaptive frequency is provided.

Abstract: A method and circuit are disclosed for detecting the performance of an oscillator circuit. In particular, the circuit may detect a signal, such as the output of the oscillator circuit, failing to oscillate as desired. The second circuit may be capable of detecting whether the signal oscillates at a frequency that is less than a predetermined frequency. The second circuit may include timing circuits for determining whether the signal remains in a first logic state for at least a predetermined period of time and whether the signal remains in a second logic state for at least the predetermined period of time.

Abstract: A method for determining at least one time constant of a reference model, which is designed as a 2nd order time-delay element of a machine. The method includes detecting an oscillation frequency of an undamped machine oscillation and determining an optimized value of a time constant of the reference model as a function of the detected oscillation frequency of the undamped machine oscillation.

Abstract: A power down system and method for an integrated circuit that enables a power down mode to be maintained for a predetermined time is described herein. The power down system comprises an oscillator, a low power oscillator and an oscillator control circuit controlling both the oscillator and the low power oscillator. The oscillator control circuit including at least one real time counter. The oscillator control circuit being so configured that the oscillator is energized when said oscillator control circuit is in a normal mode and that, when a power down signal is received: a) the oscillator control circuit measures an oscillation frequency of the low power oscillator, b) the oscillator control circuit uses the measured oscillation frequency of the low power oscillator to set the real time counter so as to maintain the power down mode for the predetermined time, c) the oscillator control circuit turns off the oscillator and uses the low power oscillator for the duration of the power down.

Abstract: A self-calibrating integrated circuit includes a processor having at least one analog function used with the processor; one or more sensors adapted to sense one or more environmental parameters of the at least one analog function; and a solid state memory being configured to store the one or more environmental parameters of the at least one analog function.

Abstract: An electromagnetic resonant sensor has a dielectric sensor body through which electromagnetic wave energy is propagated. The sensor body has a cavity, with surfaces facing one another to define a gap that varies as a function of a parameter to be measured. The resonant frequency of an electromagnetic standing wave in the body and the variable gap changes as a function of the gap dimension.

Abstract: An oscillator circuit for use with a wire-loop inductive sensor and method for use. The oscillator circuit highly attenuates common-mode noise detected by the wire-loop and differential noise from both ambient and crosstalk sources are filtered by active isolation.

Abstract: A Lorentz force-driven mechanical resonator apparatus that utilizes a high-Q resonant structure as both a mixing device and a high-Q bandpass filter. Specifically, an external time varying, but quasistatic, magnetic field is applied to the resonating device while simultaneously running a time varying electrical current through the device. The resulting Lorentz force (I×B) is proportional to the vector product of the electrical current in the bar (I) and the external magnetic field (B). Integrating such a resonant device with a magnetic field coil produces the functionality of an ideal radio frequency (RF) mixer coupled with a high-Q intermediate frequency (IF) filter. Wide tunability provides the capability to scan, or even step, an array of filters having very narrow bandwidths via a common local oscillator to a desired frequency range.

Abstract: A method is provided for aligning the center frequency of an infrared transmitter. The method comprises the steps of: (a) providing a voltage-controlled oscillator for driving the infrared transmitter, where the oscillator is adapted to receive a bias voltage from a microprocessor; (b) applying a bias voltage to the oscillator; (c) receiving an output signal from the infrared transmitter into an infrared receiver; (d) determining a frequency associated with the output signal; and (e) adjusting the bias voltage based on the frequency associated with the output signal, thereby aligning the center frequency of the infrared transmitter.

Abstract: There are provided a stable and highly sensitive nanometric mechanical oscillator having a considerably high detection resolution that enables detection of variation in force or mass on the nanometer order, as well as a method of fabricating the same, and a measurement apparatus using the same. A nanometric mechanical oscillator (10) includes a base (11), a tetrahedral oscillator mass (13); and an elastic neck portion (12) for connecting the base (11) and the tetrahedral oscillator mass (13). The oscillator (10) assumes a mushroom-like shape and has a nanometric size. The oscillator mass (13) assumes a tetrahedral shape and is suitable to be used as a probe of a scanning forth microscope in which the oscillator mass (13) serving as a probe is caused to approach to an arbitrary sample surface in order to observe the surface state.

Abstract: A known oscillator with a 2-terminal coil without a tapping has only a limited dynamic controllability and apart from this is unsuitable for implementation in CMOS technology. The oscillator, first of all is extended by a current mirror. By the addition of the current mirror Q3, Q4 and additional power supply sources, one achieves a greater dynamic controllability and the suitability for implementing it in CMOS technology. By means of the excitation of the oscillating circuit with switched current sources Io, one achieves the proportionality of the oscillation amplitude to Rp and Io. In practice more complicated structures are used for switches and current sources. With this, an additional controllability of the oscillation amplitude independent of the damping of the oscillating circuit is obtained. The method is-used for distance measurement. The additional control of the oscillation amplitude is utilized for the correction of the manufacturing tolerances and of the temperature-dependence.

Abstract: An apparatus for measuring the inductance of a wire-loop with noise-cancellation, auto-calibration and wireless communication features, or detector circuit. The apparatus measures the effective change in inductance induced in a wire-loop as a vehicle passes over the wire-loop to produce an inductive signature corresponding to a vehicle.

Abstract: A calibration circuit and method for a proximity/touch detector allow automatic calibration to the proximity/touch detector components, chassis affects, and ambient conditions such that initial factory calibration and periodic manual calibration are not needed. The calibration circuit switches a capacitance into the input capacitance of a Schmitt trigger free running oscillator to change the output frequency of the oscillator. A capacitive sensor forms part of the input capacitance. The change in frequency simulates the frequency shift associated with the difference in input capacitance generated when an object, such as a finger, is touching the capacitive sensor and when the capacitive sensor is free from contact with the object.

Abstract: A coin validator tests a coin using a pair of coils coupled in an oscillator circuit which is arranged to drive both the coils concurrently at two separate frequencies without interference therebetween, each frequency signal being influenced by the presence of a coin. Preferably, the coils are connected in series in a feedback loop to form a first oscillator, and the second oscillator is coupled to the interconnection between the coils the other ends of which are effectively short circuited at the frequency of the second oscillator.

Abstract: The present invention is a button on a device that has the ability to detect when a finger touches or is proximate to the button, especially to cause the initiation of a particular feature/function of the device. The button includes a proximity detector that is operable to sense or detect when a user's finger is proximate or on the button. The proximity detector may take many forms. These forms may be combined to provide greater selectivity. Additionally, sensitivity of the proximity detector may be set via threshold values. Sensitivity of the proximity detector correlates to detection or sensing of a user's finger at various distances from the button. One application is as an autofocus/shutter button on a camera.

Abstract: A low power, frequency-mode magnetometer. The magnetometer includes an LC oscillator, a bias resistor and a polarity switch. The LC oscillator produces an output signal having a variable frequency indicative of both a magnitude and a polarity of a magnetic field. The LC oscillator includes an inverting amplifier and a Pi network including an inductor and two capacitors. The inductor is realized as a coil wound about a high permeability, low hysteresis, core material that has been longitudinally cut. The inductor is coupled between an input node and an output node, as is the inverting amplifier. The inverting amplifier has a first trigger voltage and a second trigger voltage, which are symmetrically located with respect to one half of a DC bias voltage. The bias resistor is coupled between the input node of the LC oscillator and a first node and controls the DC bias current to the inductor. The polarity switch switches the first node between ground and the bias DC voltage.

Abstract: A weighing apparatus includes a SAW oscillator and a “push oscillator” to force the SAW oscillator into a desired mode of operation. A SAW temperature oscillator and a thermistor are also provided. The frequency of the “push oscillator” is made immune to temperature changes by generating it via a mixer mixing the SAW temperature oscillator with an adjustable fixed frequency oscillator. Long term stability of the SAW temperature oscillator is achieved by periodic calibration with the thermistor.

Abstract: A frequency control apparatus controls the frequency of an output signal thereof in synchronism with an externally input timing signal. A variable frequency oscillator generates the output signal such that the output signal has a frequency thereof variable in response to a control signal input to the variable frequency oscillator. An input device receives the timing signal. A checking device checks a monitor amount variable in response to the frequency of the output signal from the variable frequency oscillator, in timing in which the timing signal is input. A calculating device calculates a difference between the checked monitor amount and a predetermined desired amount. A control device controls the control signal input to the variable frequency oscillator such that the calculated difference becomes zero.

Abstract: This Inductive Displacement Transducer relates to a new and useful set of embodiments for a comparator-type relaxation oscillator circuit where the frequency is controlled by variable inductance. Each oscillation of said circuit discharges a fixed amount of charge such that an increase in frequency increases the total current draw of the circuit.

Abstract: The present invention provides a magnetic-field sensor using a magnetic substance. In the magnetic-field sensor, a transmission-line element constituted of a conductor layer, dielectric layer and a magnetic layer is inserted in a feedback circuit of a phase-shift type oscillation circuit using an open-loop operational amplifier as an amplifier. An output of the operational amplifier is fed back to an input thereof through the transmission-line element. Thus, a variation in oscillation frequency depending upon the intensity of an external magnetic field is detected as an output of the sensor.

Abstract: A road vehicle sensor provides an output signal having a magnitude which varies with time through a plurality of values as a vehicle passes the sensor. Signal processing apparatus monitors the timing of sensor signals generated from sensors in adjacent lanes of a highway and provides an indication when such sensor signals could correspond to a double count with a single vehicle being detected by both sensors. Then, the geometric mean of the amplitudes of the sensor signals from the sensors in adjacent lanes is calculated and is used to indicate a double count if the geometric mean is below a threshold value. Signal processing arrangements are also described to detect tailgating vehicles which may be simultaneously detected by a sensor, and for determining the length of slow moving or stationary traffic.

Abstract: A pager system for monitoring the operation of a plurality of controllers in each one of a plurality of agricultural field equipment in a group. A plurality of sensors are provided at each location of agricultural field equipment wherein a sensor connects through an isolation device to one of the controllers for issuing a status signal corresponding to the present status of the connected controller. Whenever the status of a controller changes, the remote terminal unit immediately transmits the changed status symbol as well as the status of the other sensors to a central control computer. The central control computer analyzes the transmitted status signals for generating a changed status paging message and delivers the changed status paging message, identifying the agricultural field equipment having the changed status, as well as the unchanged status messages from all remaining agricultural field equipment in the group.

Abstract: An oscillator circuit for use with a wire-loop inductive sensor and method for use. The oscillator circuit includes two balanced capacitors coupled to the wire-loop sensor, and an excitation circuit connectable with the capacitors at a selected polarity. Wherein, when the excitation circuit is connected to the capacitors, one of the capacitors is charged while the other capacitor is discharged, and both of the capacitors are discharged when the excitation circuit is disconnected to produce a pair of decaying oscillations having a caduceus-shaped output. The oscillator circuit highly attenuates common-mode noise detected by the wire-loop and differential noise from both ambient and crosstalk sources is filtered by active isolation.

Abstract: When output signals of an oscillator are binarized by binarization means, a timing signal for driving a sequence controller for controlling a correction portion is rested temporarily. The process for overwriting the contents of an E2ROM of the correction portion side with an RAM is rested temporarily. This can prevent noise produced at the overwriting timing. Binary signals after binarization can be prevented from being varied. The oscillator can be driven stably so as to give an angular speed output with high accuracy.

Abstract: A mass sensor includes a diaphragm, a sensing plate having a piezoelectric element arranged on at least a part of at least one surface joining respective sides, a connecting plate sandwiched by the diaphragm and the sensing plate, wherein the diaphragm, the sensing plate, the piezoelectric element, and the connecting plate form a resonating portion. The connecting plate is bridged across the side surfaces of a concave portion formed in a sensor substrate, and the sensing plate is joined to at least the bottom portion of the concave portion. Change in the mass of the diaphragm is measured by measuring change in the resonant frequencies of the resonating portion accompanying the change in the mass of the diaphragm. The mass sensor enables the easy and accurate measurement of a minute mass of a nanogram order including microorganisms such as bacteria and viruses, or chemical substances, or the thickness of vapor-deposited films.

Abstract: An oscillator circuit for use with a wire-loop inductive sensor and method for use. The oscillator circuit highly attenuates common-mode noise detected by the wire-loop and differential noise from both ambient and crosstalk sources are filtered by active isolation.

Abstract: Sensors, systems and methods for measuring magnetic field strengths in both AC and DC magnetic fields by using CMR material in tunable, radio-frequency LC oscillators are disclosed.

Abstract: An oscillator circuit comprising first and second mutually electromagnetically couplable resonant circuits, the second circuit comprising a dielectric element and excitation means operable to produce a first frequency of oscillation, the first circuit comprising the dielectric element, excitation means including a two-terminal Schottky device, preferably a Schottky diode, operable, responsive to an applied signal, to vary the resonant frequency of the first resonant circuit, and thereby vary the frequency of oscillation of the oscillator circuit.

Abstract: A redundant inductive angle sensor has two LC oscillators of at least approximately identical design. By inductively coupling the oscillators, the oscillators synchronize themselves with respect to frequency and phase relationship so that undesirable mutual interference is prevented. This provides an inductive angle sensor, which is able to function even if one of the LC oscillators becomes inoperative.

Abstract: An inductive proximity sensor oscillator having a differential comparator in combination with a negative feedback network and a positive feedback network connected to the comparator. The positive feedback network determines the frequency and amplitude of the generated oscillations. An LC resonant tank circuit is connected between a non-inverting input and a fixed reference voltage, and a current limiting resistor connected between the non-inverting input and the output of the comparator. The negative feedback network provides a simple, fast and reliable start-up mechanism. It comprises a capacitor connected between the inverting input of the comparator and the circuit ground and a resistor connected between the non-inverting input and output of the comparator.

Abstract: A fastener system employs a portable, sensing device, such as one or more reactance capacitors or an image processor such as a camera or a laser, which removably attaches adjacent to the fastener to detect and measure the change in a gap or specialized form of the bolt head or associated washer caused by the relative movement of portions of the fastener system when the fastener is under strain without contacting the sensed portions undergoing the significant relative movement. Associated electronic components process and indicate the clamp load of the fastener system.

Abstract: An oscillator 12 outputs a constant frequency as a metal object is brought close and this frequency forces oscillation of an oscillating circuit 11 which is sensitive to this metal object, at a level significantly below the critical natural frequency of the oscillating circuit. The oscillating signals S1, S2 are applied to the two inputs of a phase detector 15, such that they can be changed over by means of an inverter device 17, so that the detector can be configured in ferrous mode or in non-ferrous mode.

Abstract: An integrated oscillator and associated methods are provided for providing clock signals. The integrated oscillator preferably includes a micro-mechanical oscillating circuit for providing an oscillating clock signal. The micro-mechanical oscillating circuit preferably includes a support layer, a fixed layer positioned on a support layer, remaining portions of a sacrificial layer positioned only on portions of the fixed layer, and an oscillating layer positioned on the remaining portions of the sacrificial layer, overlying the fixed layer in spaced relation therefrom, and extending lengthwise generally transverse to a predetermined direction for defining a released beam for oscillating at a predetermined frequency. The spaced relation is preferably formed by removal of unwanted portions of the sacrificial layer.

Abstract: A frequency control apparatus controls the frequency of an output signal thereof in synchronism with an externally input timing signal. A variable frequency oscillator generates the output signal such that the output signal has a frequency thereof variable in response to a control signal input to the variable frequency oscillator. An input device receives the timing signal. A checking device checks a monitor amount variable in response to the frequency of the output signal from the variable frequency oscillator, in timing in which the timing signal is input. A calculating device calculates a difference between the checked monitor amount and a predetermined desired amount. A control device controls the control signal input to the variable frequency oscillator such that the calculated difference becomes zero.

Abstract: In an oscillator comprising a resonant circuit (L, C, R.sub.CU) and an amplifier circuit (V, R.sub.1, R.sub.2, R.sub.3) connected as a negative resistance (R.sub.n), a direct current source (I.sub.1) is connected in series with the resonant circuit (L, C, R.sub.CU). In this way, a signal (U.sub.CU) is provided being a measure for the resistance of the oscillator circuit coil (L). By using this signal (U.sub.CU), a control circuit (V.sub.1, M; V.sub.2, V.sub.3, M) controls the negative resistance (R.sub.n) inversely proportional to the resistance (R.sub.CU) of the oscillator circuit coil (L). This affords a simple stabilization of the temperature behavior of the oscillator circuit (L, C, R.sub.CU) and allows the low price manufacture of inductive proximity switches having a great switching distance which function safely in a broad temperature range.

Abstract: A voltage-controlled oscillator VCO capable of reliably generating an oscillation even if it, after stopping with electric charges remaining on both of its capacitors, is restarted under the same conditions. Even if the VCO is started with charges remaining on capacitors, N-channel transistors are both turned on because outputs of differential circuits are both at H level. N-channel transistors are both turned off because their gates are connected with the drains of the N-channel transistors. Therefore, in no case, the levels at points C and D as outputs on both sides of latch circuit go to L level at the same time.

Abstract: The invention relates to an apparatus for measuring the capacitance between at least a conductive part of a wall of a vessel and a measuring electrode situated in the vessel and carrying a measuring voltage, comprising a measuring circuit and a compensating circuit for applying a compensating voltage as nearly as possible the same as the measuring voltage to conductors present in the vicinity of conductors carrying the measuring voltage, wherein the capacitance between the measuring electrode and the vessel wall is connected as frequency determining element in an oscillator, so that the frequency of the measuring signal is related to the value of the capacitance. Frequency is a quantity which can be measured much better, can be determined much more precisely, requires less complicated circuits and can be largely implemented in integrated form.

Abstract: The subject oscillation frequency generating section generates a subject oscillation frequency in response to the capacitance of subject when the subject contacts the measurement electrode. The subject recognition signal generating section generates a subject recognition signal corresponding to the subject oscillation frequency. The reference signal setting section previously sets a reference signal used to determine whether the subject is an animate body. The animate body detection control section compares the subject recognition signal and the reference signal to determine whether the subject is an animate body.

Abstract: A stabilized frequency oscillating circuit outputs a pixel clock signal to an image scanner for controlling pixel rate at various writing positions along a scan line. The circuit includes a synchronization circuit having a first control signal component output to adjust a nominal output frequency of the oscillator; and a frequency profiling circuit having a second control signal component output which varies as a function of writing position along the scan line to determine a corrected output frequency of the oscillator which varies as a function of writing position along the scan line.

Abstract: A canceler loop is used to provide negative feedback to a crystal oscillator to reduce the effects of shock and vibration on the spectral purity of the crystal oscillator. The canceler loop demodulates the output of the crystal oscillator and supplied a stabilizing voltage representative of the demodulated output to cancel frequency modulation induced by shock and vibration. The stabilizing voltage is used to cancel the noise sidebands of the frequency spectrum of the crystal oscillator output without tuning the center frequency.