65results about How to "Reduce system noise" patented technology

Agile frequency converter and method, IF-RF level exchange process, and notch filtering techniques. System noise and spurious levels generated by channel frequency conversion is reduced in applications requiring broadband combining of frequency converters to form multichannel composite signal. Converter employs two-stage frequency conversion process, with gain exchange system using variable pre-mixer gain and variable post-mixer attenuation to maintain constant RF output signal power level. For those few conversion frequencies where distortion component(s) cannot be filtered without degrading desired signal, IF-RF level exchange is optimized for meeting the carrier-to-distortion (C / D) ratio specifications at slight expense of noise level for that channel only, while still meeting aggregate combined carrier-to-noise (C / N) specification requirements. Optimal apportionment of level exchange for each channel depends on specific frequency rejection capability of spurious components and is matched to filtering capability and stored within non-volatile memory of a microcontroller used in the frequency converter.

A cooling system for an off-highway vehicle includes a heat exchanger (e.g., an engine coolant or hydraulic oil heat exchanger) and a fan mechanism for flowing air along a flow path through the heat exchanger. In the improvement, the fan mechanism is a centrifugal fan mechanism and is substantially the sole means for flowing air along the flow path. That is, there is substantially no ram-urged air. The mechanism includes a housing and a fan in the housing. The fan has forward curved blades, thereby to reduce system noise. A preferred fan has a depth-to-diameter ratio not in excess of about 0.4 and, most preferably, not in excess of about 0.25. An alternate embodiment includes what might be termed a split-discharge arrangement wherein air blown by the fan is discharged along two paths.

A system and method for providing interleaving point-of-load (POL) regulators such that each regulator's switching cycle is phase displaced with respect to those of other POL regulators in the array is disclosed. As a result, the aggregate input and / or output reflected ripple and noise of the input, output, or both is reduced. Each regulator in the array is associated with an unique address. A serial data-line writes the phase spacing programmed to each addressable POL regulator in the array. The present invention permits phase displacement of POL regulators without limitation to the input and output voltages of each of the regulators in the array. The array of POL regulators may also operate in a phase displaced mode with only a single control line. The need for separate controllers and multiple control lines is thereby eliminated.

Systems that sample a continuous analog time-domain signal. The invention is particularly applicable to systems whose analog components have a bandwidth limit below that desired or specified. The invention has been created to address particular problems in the design of digital sampling oscilloscopes (DSOs) that require more bandwidth than that which is easily achievable through traditionally analog techniques. A method and apparatus are provided in the form of a digital filter that is capable of surgically increasing the bandwidth of the system beyond the bandwidth achievable in an analog system. Furthermore, it is demonstrated that this system can perform this bandwidth increase without degradation in the time-domain performance of the system such as pulse or step response. In some cases, the time-domain performance is improved by flattening of the frequency response. Additionally, the system, while boosting the bandwidth, is capable of simultaneously removing noise and therefore producing a digitized signal of higher fidelity than that obtained without the filter in place.

An entertainment system for use with a magnetic resonance imaging (MRI) device that includes video glasses and headphones. A Faraday shield encloses the entertainment system to reduce adequately RF signals from entering or leaving the entertainment system. The entertainment system may have non-ferromagnetic RF low-pass filters between parts of the system, such as the control unit and the video glasses, to reduce higher RF signals from entering or leaving those parts. To replace the battery and or entertainment media, a person opens the entertainment system's Faraday shield when not MRI imaging or outside the MRI magnet room. The door has an Faraday shield overlapping the system Faraday shield and making low resistance RF contact. The entertainment system has a minimal amount of ferromagnetic material so that it may operate within the high magnetic field of the MRI magnet bore with minimal performance degradation. The entertainment system uses non-ferromagnetic speakers in the headphone. Passive ear protection and noise cancellation reduce the loud noise of the MRI system heard by the patient to a level where the patient can hear the entertainment. The entertainment system includes a charger for the rechargeable batteries.

In one aspect of the present invention a method has steps for taking downhole measurements. A network integrated into a downhole tool string in a well bore may be in communication with a downhole sensor, the downhole sensor having a downhole clock that may be in communication over the network with and synchronized with a top-hole clock source. A signal source may be within a transmitting distance of the downhole sensor and may be activated. The downhole sensor records signals from the signal source at a recorded time when the network is disconnected from the top-hole clock source. When the network is reconnected, the downhole clock and the top-hole clock source are re-synchronized. The clock drift that occurred during the disconnection may be calculated. The recorded time may be adjusted to reflect what it would have been if the downhole clock had been synchronized with the top-hole clock source.

A system and method for providing interleaving point-of-load (POL) regulators such that each regulator's switching cycle is phase displaced with respect to those of other POL regulators in the array is disclosed. As a result, the aggregate input and / or output reflected ripple and noise of the input, output, or both is reduced. Each regulator in the array is associated with an unique address. A serial data-line writes the phase spacing programmed to each addressable POL regulator in the array. The present invention permits phase displacement of POL regulators without limitation to the input and output voltages of each of the regulators in the array. The array of POL regulators may also operate in a phase displaced mode with only a single control line. The need for separate controllers and multiple control lines is thereby eliminated.

A recognition system for a bathroom fixture operates by sending a photon pulse from an emitter, monitoring for a presence of an object within a predefined detection zone, and operating the bathroom fixture if the distance of the object is within the predefined detection zone. The monitoring occurs by detecting photons with a sensor, establishing a correlated or uncorrelated state of the detected photons, optically filtering the detected photons, calculating a distance of the object from the sensor based on the photon pulse sent from the emitter and the returned photons collected at the sensor, and determining whether the distance of the object from the sensor falls within the predefined detection zone.

The invention provides a device for realizing high-sensitivity distributed sound wave sensing based on a small-diameter multimode optical fiber. The device comprises the components of a light source first optical fiber coupler, a pulse modulator, an optical amplifier, a frequency shifter, an optical circulator, a single-mode optical fiber, a fusion part, a small-diameter multimode optical fiber, a second optical fiber coupler, a double-balance detector, and an information acquisition and processing unit. After amplification by means of the optical amplifier, a signal is input into the small-diameter multimode optical fiber through the optical circulator. Backward Rayleigh scattering light in the small-diameter multimode optical fiber is transmitted back through the optical circulator, thereby realizing heterodyne beat with the other path of intrinsic light which is shifted by the frequency shifter. A beat frequency optical signal is converted to an electric signal through the detector, and then data signal acquisition and processing are performed. The small-diameter multimode optical fiber according to the invention can greatly improve sensing signal strength and greatly improves sound wave sensing sensitivity. A distributed sound wave sensing system based on the small-diameter multimode optical fiber can realize real-time high-sensitivity monitoring and positioning of a sound wave signal in the range of an ultra-long-distance sensing optical fiber.

A data processing node includes a local clock, a slave port and a time synchronization module. The slave port enables the data processing node to be connected through a node interconnect structure to a parent node that is operating in a time synchronized manner with a fabric time of the node interconnect structure. The time synchronization module is coupled to the local clock and the slave port. The time synchronization module is configured for collecting parent-centric time synchronization information and for using a local time provided by the local clock and the parent-centric time synchronization information for allowing one or more time-based functionality of the data processing node to be implemented in accordance with the fabric time.

A method for taking seismic measurements that includes a downhole sensor positionable within a tool string located within the bore of a well, the tool string having a network which effects communication with a downhole sensor. The downhole sensor includes a downhole clock that may be placed in communication over the network with the top-hole clock for synchronization. A seismic source is positioned within a transmitting distance of the downhole sensor and activated at a time when the network is disconnected. The downhole sensor records signals from the seismic source at along with a downhole timestamp from the downhole clock. When the network is reconnected, the downhole clock and the top-hole clock are re-synchronized and any downhole clock drift is calculated. The recorded downhole timestamp may then be adjusted to reflect what it would have been if the downhole clock had been synchronized with the top-hole clock.

A cooling device for use with a projection apparatus is disclosed. The cooling device includes a first axial fan and a second axial fan which is disposed adjacent to the heat generating portion of a light source device. The second axial fan comprises an inner end and an outer end disposed on the opposite side of the inner end. An airflow guiding device is disposed onto the outer end, in which the guiding device comprises an airflow outlet and an airflow inlet with an area greater than that of the airflow outlet. The airflow inlet of the guiding device shields at least a portion of the outer end of the second axial fan.

User input devices (UIDs) for controlling a surgical robotic system are described. A UID can include one or more tracking sensors to generate respective spatial state signals in accordance with a pose of the UID. At least one of the tracking sensors can be a camera. In the case of multiple tracking sensors, the spatial state signals are processed by a sensor fusion algorithm to generate a more robust, single tracking signal and a quality measure. The tracking signal and the quality measure are then used by a digital control system to control motion of a surgical robotic system actuator that is associated with the UID. Other embodiments are also described and claimed.

The invention relates to the field of detection of gas decomposed products and particularly relates to an SF6 gas decomposed product detection device and an SF6 gas decomposed product detection method based on a photoacoustic spectrometry technology. The SF6 gas decomposed product detection device comprises a shell, wherein the shell is internally provided with a single chip microcomputer and an accessory circuit thereof; the single chip microcomputer and the accessory circuit thereof are connected with a power supply; the single chip microcomputer is connected with an infrared light source by a power switch tube; the infrared light source is arranged opposite to a light source entrance port of a photo-acoustic cell; the photo-acoustic cell is internally provided with a resonant cavity; circular holes communicated with the resonant cavity are formed in the two sides of the photo-acoustic cell; microphones are mounted in the circular holes in the two sides; the microphones are connected with the single chip microcomputer by lock phase amplification circuits; the single chip microcomputer is connected with a display screen; an air inlet and an air outlet which are communicated with the resonant cavity are arranged at the upper end of the photo-acoustic cell. According to the SF6 gas decomposed product detection device and method, the problems of cross interference and electrode poisoning in an electrochemical method are avoided; the system noise is lowered, the detection accuracy is improved, the structure is simple and compact, the volume is small and the stability is good.

In a digital hearing aid device with an output amplifier having a sigma-delta modulator, the output transducer has a high current consumption even when no output signal perceivable as an acoustic output signal is generated. A linear digital filtering in connection with the sigma-delta modulation reduces the number of the high-frequency edges in the (typically) pulse-density-modulated output signal.

System and method for content-addressable search of holographically stored data primarily optimized with respect to search performance. A search is performed, by a holographic correlator system, on a structured representation of original data, stored in a holographic data storage medium. In a first aspect, orthogonal phase encoding of both data storage and search pages provides improvement of correlator system signal to noise ratio and dynamic range. In a second aspect, correlator incorporates heterodyne detection of a plurality of correlation signals, obtained by modulation and amplification thereof by a plurality of frequency-shifted reference beams. In a third aspect, the invention provides a method whereby multiple searches can simultaneously interrogate a single data storage location.

System and method for content-addressable holographic data storage, primarily optimized with respect to search performance. A structured representation of original data, such as represented by metadata, is provided and stored in a holographic data storage medium on which a search can be performed using a holographic correlator. Phase encoding of both data storage and search pages provides improvement of correlator system signal to noise ratio and dynamic range. Heterodyne detection is also used to provide amplification to a plurality of correlation signals by modulation thereof by a plurality of reference beams. In another aspect, increase in the storage density of the holographic data storage medium and the throughput of a holographic correlator is achieved by employing a content-addressable storage scheme, using a priori knowledge of content provided by metadata to organize data according to a selectable content relationship and store related data as a contiguous cluster.

The invention belongs to a motor pump, and particularly discloses a motor pump for a hydraulic system. The motor pump comprises a plunger pump assembly, a motor assembly and a rotary transformer assembly, and the two ends of the motor assembly are fixedly connected with the plunger pump assembly and the rotary transformed assembly respectively. The design that high integration of a brushless motor and a plunger pump is adopted in the motor pump, the structure space is effectively reduced, and the motor pump is small in size, low in weight, compact in structure and high in sealing reliability.

A method and apparatus is provided for bucking a magnetic field of known geometry and time variation by means of a plurality of bucking loops. It utilizes multiple loops, each of which is energized by an electric current that creates a magnetic field of the known time variation. The multi-loop field forms a bucking magnetic field that better opposes the spatial variation in the known magnetic field over a volume than can the magnetic field from a single loop. The present invention is useful in electromagnetic measurements, where the magnetic field of a controlled source transmitter must be annulled at a magnetic field sensor. It is particularly useful for cases where the magnetic sensor may move relative to the transmitter, such as in certain airborne electromagnetic measurements.

An entertainment system for use with a magnetic resonance imaging (MRI) device that includes video glasses and headphones. A Faraday shield encloses the entertainment system to reduce adequately RF signals from entering or leaving the entertainment system. The entertainment system may have non-ferromagnetic RF low-pass filters between parts of the system, such as the control unit and the video glasses, to reduce higher RF signals from entering or leaving those parts. To replace the battery and or entertainment media, a person opens the entertainment system's Faraday shield when not MRI imaging or outside the MRI magnet room. The door has an Faraday shield overlapping the system Faraday shield and making low resistance RF contact. The entertainment system has a minimal amount of ferromagnetic material so that it may operate within the high magnetic field of the MRI magnet bore with minimal performance degradation. The entertainment system uses non-ferromagnetic speakers in the headphone. Passive ear protection and noise cancellation reduce the loud noise of the MRI system heard by the patient to a level where the patient can hear the entertainment. The entertainment system includes a charger for the rechargeable batteries.

Disclosed is a power control method for a radio frequency power amplifier, comprising the following steps: S1. reading a power source voltage signal and a power control signal and generating an amplified signal having a linear relationship with the power control signal; S2. according to the amplified signal and saturation information, generating one or more controlled currents, merging each controlled current, and converting the merged total current into voltage; S3. Conducting linear voltage regulation on the converted voltage and generating a base control voltage of the radio frequency power amplifier. The present invention dynamically monitors the saturation information of a pass element to change the base voltage of the radio frequency power amplifier, thus improving additional power efficiency of the radio frequency power amplifier at multiple power level and over a large power source voltage range, and improving the properties of the radio frequency switch thereof.

The invention provides a device for detecting methane and carbon dioxide in atmospheric greenhouse gas based on a photoacoustic spectrum technology and relates to the technical field of gas detection by utilizing optical detection. A laser I emits light beams I which are reflected by a reflector and reflected by a high-transmission high reflector; a laser II emits light beams II which are transmitted by the high-transmission high reflector; and the light beams I and the light beams II penetrate through a photoacoustic cell via a chopper to enter a photoelectric detector. A resonant cavity of the photoacoustic cell is connected with an optical microphone, the optical microphone is connected with a lock-in amplifier, the chopper is connected with the lock-in amplifier, and the lock-in amplifier and the photoelectric detector are respectively and electrically connected with a computer. According to the device disclosed by the invention, the technical problems of poor signal-to-noise-ratio stability and poor ambient interference resistance existing in the prior art are solved. The device disclosed by the invention has the beneficial effects that the noise of the system is effectively lowered, the stability of the system is improved, and the device is suitable for long-term monitoring. Meanwhile, two gases, namely methane and carbon dioxide, are monitored, and a technical basis is provided for researching the influence of greenhouse gases on weather.

In order to provide a technique for reducing system noise from an output signal value (measurement data), an X-ray CT apparatus includes an X-ray generation unit that irradiates X-rays to an object, an X-ray detector that detects the X-rays transmitted through the object, a correction processing unit that corrects an output signal from the X-ray detector, and a reconstruction calculating unit that reconstructs an image on the basis of an output from the correction processing unit, in which the X-ray detector includes arranged detection elements, and in which the correction processing unit maintains an average value of output signal values of a plurality of predetermined detection elements centering on a focused detection element among the detection elements, and also reduces a variance of the output signal values of the plurality of predetermined detection elements centering on the focused detection element.

An optimized pseudo-random period pattern can reduce audible noise in a system that includes an inverter circuit configured to provide power to an electric machine. A system can include a PWM optimization module (POM) comprising the PPP. A carrier period for a carrier signal used to provide PWM inverter drive signals can be selected in accordance with the PPP. The PPP can be expressed as an array of 200-400 elements, each element a period belonging to a finite set of 2 or more predetermined periods. A period can be selected by index from the array, and the index incremented to progress through the PPP, which can be repeated upon its completion. The PPP can be optimized to reduce audible noise while mitigating inverter losses. Modeling techniques can determine the number of array elements, the number of possible periods, and the period values that optimize the PPP.

The adjustable voltage regulator under control of a microcontroller applies controlled amplitude voltage in the range of 5 to 9 VDC to the sensor transmitter to adjust the output amplitude of the transmitter. The adjustable amplitude transmitter allows an occupancy sensor to have its total output energy adjusted to reduce environmental noise-induced false triggering and to conform to the area to be covered. Lowering the total ultrasonic energy in the monitored space lowers the sensitivity of the receiver to inappropriate activations. Lowering the input power to the transmitter also lowers the total internal system noise and provides an improved signal to noise ratio in the receiver.

An active ultrasonic room occupancy sensor with the output amplitude of the transmitter controlled by the amplitude of power applied to the transmitter to control the zone of coverage for a sensor. An adjustable voltage regulator under control of a microcontroller applies controlled amplitude voltage to the transmitter to adjust the output amplitude of the transmitter. The adjustable amplitude transmitter allows an occupancy sensor to have its total output energy adjusted to conform to the area to be covered. Lowering the total ultrasonic energy in the monitored space lowers the sensitivity of the receiver to inappropriate activations. Lowering the input power to the transmitter also lowers the total internal system noise and provides an improved signal to noise ratio in the receiver. Alternatively, the power applied to the receiver may also be controlled by an adjustable voltage regulator under control of the microcontroller to improve receiver efficiency.

The embodiment of the invention discloses a two-phase cooling device used for achieving natural heat dissipation and air cooling, and effectively improving efficiency of the natural heat dissipation and performance of wind and sand prevention. The two-phase cooling device comprises a condenser and a fan. The fan is arranged at the top or the bottom of the two-phase cooling device, and the condenser is arranged in the two-phase cooling device in an inclined or perpendicular mode. The two-phase cooling device further comprises a first air opening formed corresponding to the fan in position, and the condenser is arranged between the fan and the first air opening. Shutters are arranged around the condenser and connected through link mechanisms. An air cylinder is further arranged on the shutters and used for controlling the shutters to open or close. The two-phase cooling device further comprises a second air opening formed in the position the same as that of the fan. A gravity shutter is installed on the air outlet of the fan. Through control over the two-phase cooling device, the two-phase cooling device can be made to form a natural heat dissipation state or form a forced air cooling air channel.

The present invention prevents peak noise caused by a resonance frequency, and reduces an overall noise of the system by binding core teeth of a stator of a BLDC motor with a vibration prevention member.To do this, the present invention provides a brushless DC motor for a washing machine including a stator including a frame, a core in the frame, and a plurality of core teeth each extended outward from the frame and having a coil wound thereon, a rotor mounted to surround the core teeth, and rotatable when power is provided to the stator, and a vibration prevention member connected between the core teeth to bind the core teeth to each other, for prevention of vibration of the core teeth.

In a digital hearing aid device with an output amplifier having a sigma-delta modulator, the output transducer has a high current consumption even when no output signal perceivable as an acoustic output signal is generated. A linear digital filtering in connection with the sigma-delta modulation reduces the number of the high-frequency edges in the (typically) pulse-density-modulated output signal.