177 results about "Internal feedback" patented technology

A hearing aid circuit includes a correlation detector that detects correlation at a feedforward path input and that provides a correlation output to a phase shifter. The phase shifter introduces a phase shift along a feedforward path. A phase measurement circuit measures a phase shift at a feedforward path input, and provides a phase measurement output to an internal feedback processor. The internal feedback processor adjusts internal feedback as a function of the phase measurement to suppress coupling of external audio feedback along the feedforward path.

The present invention discloses a high dynamic range imager circuit and a method for reading high dynamic range image with an adaptive conversion gain. The high dynamic range image circuit includes a variable capacitor. The capacitance of the variable capacitor is adjusted according to sensed light intensity or by internal feedback control, to adaptively adjust the conversion gain of the high dynamic range image circuit as it reads a signal which relates to a pixel image sensed by an image sensor device. In each cycle, the signal can be read twice or more with different dynamic ranges, to enhance the accuracy of the signal.

An ultra miniature hearing device for extended wear entirely in the ear canal past the cartilaginous region is provided. The hearing device comprises a microphone and a speaker, each having a respective diaphragm. The speaker and microphone are placed parallel to each other in a single lateral assembly. The microphone and speaker can be arranged such that their diaphragms are orthogonal to one another so that cross coupling of vibrations is minimized, thus reducing internal feedback. Due to the parallel co-placement of the speaker and microphone in the single lateral assembly, the length of the device is substantially shorter than that of prior hearing aid devices. The hearing device is 12 mm or less in length to fit in the bony part of the ear canal for most individuals and is placed within approximately 3 mm from the eardrum.

The invention discloses a percutaneous closed-loop control charging device for implantation type medical treatment instrument and belongs to the technical field of implantation medical instrument. The percutaneous closed-loop control charging device for implantation type medical treatment instrument comprises an external charger and an internal implantation type medical instrument. An external energy transmitting coil is a large-size flat magnetic core coil, and an internal energy receiving coil is a hollow coil; the external energy transmitting coil transmits electromagnetic energy by adopting a resonance electromagnetic coupling manner with parallel central shafts; and the electrical energy obtained by the internal energy receiving coil charges an internal rechargeable battery through an internal charge control circuit. The closed-loop control charging device communicates in a pulse position modulation manner for closed-loop control to ensure the energy received by the implantation medical instrument in different charging phases to be within the normal range, effectively control the heating and increase the safety; the closed-loop control charging device calculates the efficiency by the internal feedback parameter to realize counterpoint prompt and increase the charging efficiency. The percutaneous wireless charging method can charge the implantation type medical instrument by a titanium casing, is safe and reliable in charging, and can be applied to all types of implantation type medical instruments equivalent to a deep brain stimulator in power level.

A wireless repeater includes an internal feedback path for adaptively cancelling an echo between an output antenna and an input antenna. The internal feedback path employs an adaptive algorithm implementing a list having a plurality of list elements. Each list element has one or more echo cancellation parameters and one or more repeater settings. The list may be pruned by employing a minimum distance between elements within the list. A method for stabilizing a wireless repeater includes obtaining an autocorrelation of a signal in a signal path of the repeater, detecting an echo in the signal path based on the autocorrelation, providing a list of elements indicating past successful echo cancellation coefficients and associated repeater settings, and adaptively adjusting an error of the echo cancellation coefficients to cancel the echo in the signal path.

Stable adaptive filter and method are disclosed. The invention solves a problem of instability associated with Fast Affine Projection adaptive filters caused by error accumulation in an inversion process of an auto-correlation matrix. The Stable FAP uses a simplification of setting a normalized step size close to unity and reduces a problem of the matrix inversion to solving a system of linear equations whose solution coincides with a first column of the inverse auto-correlation matrix. The system of linear equations is then solved by one of descending iterative methods which provide inherent stability of operation due to intrinsic feedback adjustment. As a result, inevitable numerical errors are not accumulated, being corrected as the process goes on. In first and second embodiments of the invention the system of linear equation is solved by steepest descent and conjugate gradient methods respectively. Being immune to numerical errors, the invented method and filter are suitable for various DSP platforms, e.g., 16 and 24 bit fixed-point as well as floating point platform.

A system and method for controlling an internal combustion engine for low emissions include an inner feedback control loop to control the engine fuel/air ratio with feedback provided by a first exhaust gas sensor and an outer feedback control loop that modifies the fuel/air ratio reference provided to the inner feedback control loop based on feedback signals provided by the first exhaust gas sensor and a second exhaust gas sensor. The fuel/air ratio reference signal controller adapts to the oxygen storage capacity of the catalyst by modeling the catalyst as an integrator with an unknown gain and estimating the catalyst gain based on the first and second exhaust gas sensor signals. Using the estimated catalyst gain, an adaptive controller gain factor is determined and subsequently used to determine the fuel/air ratio reference signal provided to the fuel/air ratio controller of the inner feedback control loop.

A packaged LED array for high temperature operation comprises a metal base, the metal base including an underlying thermal connection pad. One or more layers of ceramic overly the metal base. The array includes a plurality of LED die, each LED die having electrodes. And, the LED thermally coupled to the metal base. A driver circuit is electrically connected to the LED die electrodes and controls the LED array current. An LED driver is mounted within the LED array package, and thermally coupled to the metal base. In a second embodiment, one or more of the LED die can be switched from the driver to a measurement circuit and used as a photodetector to measure the light output of the LED array. The measured photodetector signal can further be used as a feedback signal to control the LED array light output.

A valve actuator control monitors engine valve trajectory, lift and seating velocity and varies the timing of internal feedback control channels to correct for engine valve positioning errors to achieve precise engine valve lift, closing timing and desired seating velocity.

Disclosed is a device and method for preventing seizures due to physiological system dysfunction. The method is based on a conjectural model of the brain wherein each brain site is modeled as a chaotic oscillator; a normal brain generates an internal feedback signal to prevent long-term entrainment among the oscillators; and a pathological brain fails to provide this feedback signal. The device of the present invention measures and characterizes the brain sites to determine if entrainment is occurring among the oscillators, derives an appropriate feedback signal to counteract the entrainment, and applies the feedback signal to the critical brain sites. The feedback signal generated by the device supplements or takes the place of the feedback signal that would otherwise be generated by the normal brain.

A wireless repeater includes an input antenna for receiving an input signal, an output antenna for outputting an amplified signal, and an amplifier for amplifying the received input signal and providing the output amplified signal to the output antenna. Radiated coupling between the input and output antennas causes echoes to be transmitted by the repeater. A filter is used for applying a weighting function to a power spectrum of a measured signal in the wireless repeater thereby obtaining a weighted power spectrum of the measured signal. An internal feedback path is employed for adaptively canceling the echo by implementing an adaptive algorithm based on a autocorrelation of the input signal employing the weighted power spectrum of the measured signal.

A low-voltage constant-impedance analog switch based on a single MOSFET [328] as the main switching element. The constant-impedance on-state operation is obtained by connecting a charged capacitor [326] between the gate and source terminals of the MOSFET [328]. The switch can be compensated for the body effect, which may be necessary to obtain the required level of linearity. Low-voltage operation is made feasible by employing an internal feedback loop that locks in the switch's on-state. The switch can be implemented in a single-well CMOS bulk technology, and it can operate at supply-voltage differences that are only slightly higher than the technology's threshold voltage.

An improved latch circuit having a dynamically adjustable internal feedback level. The improved latch circuit includes a latch inverter and a feedback inverter cross-coupled with the latch inverter. A controllable supplemental feedback inverter is connected in parallel with the feedback inverter to provide a controllable level of feedback to the latch inverter. An independently selectable control signal enables or disables the controllable feedback inverter in conformity with a need for more or less feedback, such that the internal feedback level may provide optimal functionality and performance of the latch circuit.

The invention provides a high-dynamic range image sensing circuit with adaptive conversion gain and a high-dynamic range image reading method. The high-dynamic range image sensing circuit comprises a variable capacitor. The capacitance value of the variable capacitor is adjusted according to sensed lightness or internal feedback control so as to adaptively adjust the conversion gain when a signal representing a pixel image sensed by an image sensing element is read. When signals are read per period, the signals within different dynamic ranges can be respectively read for more than two times so as to enhance the accuracy of the signals.

A current-mode DC-to-DC converter operating in a high frequency is disclosed. The current-mode DC-to-DC converter includes an inductor, a power switch, an oscillator, an adder without internal feedback loop, an error amplifier, a comparator, a compensation unit and a driver. The adder adds a ramp signal from the oscillator directly to a voltage signal relative to a current flowing through the power switch and generates a sum signal based upon match between internal components in the oscillator and the adder.

The invention discloses an implantable self-adaptive wireless power transmission system, which includes an external energy transmission module, an internal energy collection module and an adaptive feedback loop; the external energy transmission module includes a power amplification circuit, a signal source and a drive, and a transmission coil ; The power amplifying circuit adopts Class D, and is a voltage switch type; the self-adaptive feedback loop mainly includes in vivo information collection, in vivo and in vitro wireless communication, and in vitro energy control; the entire feedback structure is composed of two loops of in vivo feedback and system feedback circuit structure; the energy harvesting module in the body includes a receiving coil, a coupling capacitor, a full-wave rectification filter, a PWM modulation module, and an LSK modulation circuit. The invention proposes an implantable self-adaptive wireless power transmission system, which can not only meet the uninterrupted power supply requirements of implanted devices, but also make the energy transmission controllable and avoid excessive energy transmission.

Electro-hydraulic engine valve actuation system providing an actuator and an actuator control system. The actuator includes primary and secondary actuation chambers, defined by a piston, connected to the engine valve, and characterized by increasing and correspondingly decreasing chamber volumes, as the piston is urged away from neutral position. A fluid inlet is connected to a flow control valve. A control valve includes an actuator, and has flow states for controlling flow between two fluid inlets and a fluid outlet. The control valve includes first and second opposed, control chambers, each connected to the actuator. There is a spring in the second control chamber. The actuator of the flow control valve is controlled to a first and second state, and there is an electrically uncontrolled third flow state. There is a pair of temperature-compensated orifices which create internal feedback, with the control chambers, between the engine valve motion and the control valve position.

The invention discloses an internal-feedback-type terahertz traveling wave tube oscillator, and relates to a terahertz electromagnetic wave source technique. Based on a traveling wave tube, a feedback mechanism is introduced so as to form an oscillator. Compared with the existing traveling wave tube, the structure is characterized in that 1. a tuning device is added at an input port of the oscillator, and is a variable short circuit device; and 2. an output port is designed with a special method, so that the oscillator has certain reflection in a working frequency band, and the reflection coefficient is about 0.2. According to the oscillator provided by the invention, a feedback loop of an electromagnetic wave is introduced into the structure, the phase shift of the electromagnetic wave through the feedback loop is integral multiples of 2*pi, and under the condition that a slow wave structure provides sufficient gain, the device is oscillated, and one or a plurality of electromagnetic waves with specific frequency is/are output. Because the tuning device can introduce phase shift variations through methods of mechanical tuning and the like in the feedback loop, the frequency of a start oscillation electromagnetic wave also varies to meet the condition that the total phase shift of the feedback loop is integral multiples of 2*pi, so that the tunable characteristic is realized.

The invention relates to an internal feedback digital servo hydraulic cylinder, which belongs to the field of digital hydraulic technology and aims to solve the problems of inaccurate control and difficulty in gain adjustment of an electrohydraulic servo system. The internal feedback digital servo hydraulic cylinder comprises motors, a slide valve, a hydraulic cylinder, a magnetostrictive displacement sensor, an oil path integrated block, a supporting plate and the like. A valve core of the slide valve is driven and controlled by a first motor; a feedback turnbuckle of the slide valve is driven and controlled by a second motor; a hydraulic cylinder displacement signal is fed back to a driver corresponding to the second motor by the magnetostrictive displacement sensor; the second motor is controlled to operate by the driver; and closed-loop digital control over the hydraulic cylinder displacement is realized by controlling relative motion of the feedback turnbuckle and the valve core. The internal feedback digital servo hydraulic cylinder has the advantages of simple structure, high control accuracy, small vibration and high stability, and is suitable for working places with long-stroke and large-thrust hydraulic cylinder.