Apogee Technology, Inc.

Bose Corporation

Northrop Corporation

Michael S Danielson

Rebecca Kowalczyk

Nabin Sagar Sharma

Kyle Brian McNicholas

Meir Mechtinger

Michael W Determan

Leo Spiegel

Nevenka Golubovic-Liakopoulos

Paul William Larsen

Ping Tsui

David B Meyers

Andrew A Adrian

Paul Larsen

Glenn Fricano

Various aspects include portable speakers and methods of controlling such speakers. In a particular implementation, a portable loudspeaker includes: a controller configured to control an audio output according to at least two distinct equalization profiles and in at least two distinct physical orientations, where the controller is configured to switch between two of the distinct equalization profiles in response to detecting a change in physical orientation of the portable loudspeaker between two of the distinct physical orientations, where the switch between the two distinct equalization profiles is either: a) modified by a hysteresis factor, or b) smoothed according to a predefined pattern.

Portable speaker with orientation-dependent equalization

The invention relates to a method of fabricating a microneedle array in a substrate, a drug delivery device comprising one or more microneedles extending upwards from the front surface of the substrate, the microneedles having a generally conical-shaped body defined by a plurality of surfaces sloping upwards from a relatively broad base to a tip, and one or more substances coating the microneedles, the one or more substances being operable to be administered to a patient, wherein the tips of the one or more microneedles are sufficiently sharp to penetrate an outer layer of the skin of the patient, and a method of administering one or more substances to a patient using the device.

System and method for drug delivery and microfluidic applications using microneedles

A resonant switching power system operates with two resonant frequencies. A first frequency depends on the secondary leakage inductance of an output transformer and capacitor. The first frequency varies with changes in the load because load changes alter the leakage inductance. A second resonant frequency depends on the gate source capacitance of two MOSFET power devices in the circuit and the leakage inductance of the circuit's driving transformer. Power is thereby supplied that is always in phase with the load so that switching in the power supply occurs when current is near zero. High thermal efficiency is thereby achieved.

Adaptive resonant switching power system

Apparatus and methods for reducing radio frequency interference produced by switching amplifiers, includes a variable-order noise shaper in a system that includes an AM tuner. An alternative implementation involves determining the tuned frequency of a radio signal. A first sampling rate is provided at which the radio signal is to be sampled. The first sampling rate is associated with a plurality of first harmonic frequencies. A second sampling rate is also provided and is associated with a plurality of second harmonic frequencies different than the first harmonic frequencies. The method involves selectively sampling the radio signal at one of the first and second sampling rates, wherein the first sampling rate is selected when the first harmonic frequencies do not coincide with the tuned frequency, and the second sampling rate is selected when the second harmonic frequencies do not coincide with the tuned frequency. A still further alternative implementation for reducing RFI involves the second sampling rate being derived using linear interpolation.

Reduction of radio frequency interference (RFI) produced by switching amplifiers

A bridged amplifier output stage capable of sharing a common conductor between independent loads. Multi-Channel pulse width modulated output signals are time division multiplexed to reduce the number of required conductors. The output stages are driven such that the non-common conductor time multiplexed off-channel(s) receives a copy of the shared common signal. The differential signal on the off-channel(s) is thereby cancelled even though the common conductor is carrying a signal for use by the on-channel.

Time division multiplexed PWM amplifier

An all digital switching amplifier wherein linearization of the power switch is accomplished solely by using three states. A small, fixed width, bi-state compensating carrier waveform is added to the leading or training edges of an oversampled main input pulse producing a compensated composite waveform. This compensating carrier linearizes output from a power switch by effecting common mode cancellation of switch time errors. Output pulse width combinations for the compensating carrier are obtained from a look-up table stored in memory. A correction mechanism is implemented to correct for harmonic distortion that is dependent on the modulation level or index and results from the compensating carrier modulation. The correction mechanism applies the inverse of the modulation induced distortion to the oversampled compensated composite input signal to null distortion products resulting from the modulation scheme used to apply the small carrier to linearize the performance of the tri-state power switch. Digital timing control of the power switch's deadband ensures accuracy of the timing and sequence in which individual switches within the power switch H-bridge are turned off and turned on, so as to preclude a short circuit across the power supply. A high speed clock used in linearizing the power switch provides a timing reference to generate the necessary deadband timing delays and pulse width increments. The output bridge uses enhancement mode MOSFETs.

Digital signal processing for linearization of small input signals to a

Apparatus for compensating an optical sensor utilizing a light emitting diode and a monolithic dual element photodiode as a null position sensor for changes in optical output efficiency or gain due to variations in temperature without knowledge of relative or absolute temperature. The optical sensor includes a light emitting diode and a dual element photodiode spaced apart from the light emitting diode and located so that each element of the dual element photodiode is equally illuminated. A pendulous mass is disposed between the light emitting diode and the dual element photodiode detector such that as it moves the amount of illumination received by each of the dual elements differs. Electrical apparatus is provided for producing a first signal proportional to the difference in output from the two photodiode elements, and this signal is used to null the position of the pendulous mass. A second signal is produced which is proportional to the sum of the outputs from the two photodiode elements, and this signal is utilized to alter the current to the light emitting diode so that the second signal is maintained at a predetermined reference level. In this way, the overall gain of the optical sensor is maintained within narrow limits to compensate for temperature induced variations in sensor gain.

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Wrentham, MA, United States of America

Michael S Danielson