Hamilton Sundstrand Corporation

Robert D Klapatch

Jay W Kokas

Michael Maynard

Joshua I Goldberg

James Saloio

William E Villano

Richard E Versailles

Kerry R Querns

A differential signal conditioner circuit with common mode voltage (CMV) compensation is provided. The circuit includes a signal multiplexer that receives a input signal that includes a high and low signal and a reference CMV signal, a differential amplifier coupled to the signal multiplexer that receives the reference CMV signal and outputs a CMV error value during a first cycle, and receives the input signal and outputs an amplified difference signal during a second cycle. The circuit also includes a CMV measurement circuit that receives the reference CMV signal and outputs a confirmation value during the first cycle, and receives the input signal and outputs a CMV compensation value during the second cycle, and a processing element that receives the CMV error value, the amplified difference signal, the CMV compensation value, and a differential amplifier gain value and generates a CMV compensated output based on the received signals and values.

Differential signal conditioner with common mode voltage error compensation

A current sense system includes a current transformer having a primary coil and a secondary coil, wherein the secondary coil has a first and second terminal; a burden resistor connected between the first terminal of the secondary coil and ground; a monitor circuit that measures current in the primary coil by monitoring voltage across the burden resistor; and a built-in test (BIT) circuit connected to the second terminal of the secondary coil. The BIT circuit provides a virtual ground during normal operation, and either a positive voltage or a negative voltage during test operations.

Built-in test injection for current sensing circuit

An electric motor controller includes controller electronics configured to control an electric motor. The electric motor controller also includes a thermoelectric cooler in thermal communication with the controller electronics. The thermoelectric cooler is configured to receive a braking current associated with braking of the electric motor and provide cooling to the controller electronics.

Electric motor braking using thermoelectric cooling

A method and apparatus for generating a wave shaped pulse electronic signal of a predetermined format from a square pulse signal generator. A signal is applied from the square pulse generator to circuitry having a plurality of transmission lines. Each transmission line having a certain length creating a certain signal time delay and signal reflection for a signal applied to the circuitry from the square pulse generator so as to create a delay pulse from each transmission line. Each delay pulse is combined from each transmission line to generate the wave shaped pulse electronic signal of a desired predetermined format.

Generating signal waveforms of a predetermined format

A solid-state alternating current (AC) switch provides for the sequential turn-on of the associated solid-state switches to reduce the generation of electromagnetic interference (EMI). The solid-state AC switch includes at least first and second solid-state switches connected in series between an AC input and an AC load. A zero-cross detector circuit monitors the AC input to determine zero-crossings associated with the monitored AC input. A controller turns on the first solid-state switch and the second solid-state switch according to a turn-on sequence in which the first transistor is turned ON during a detected zero-crossing window associated with the first transistor and the second transistor is subsequently turned ON during a detected zero-crossing associated with the second transistor.

Solid-state alternating current (AC) switch

A messaging system for a rotating airfoil system is provided that includes a stationary structural member supporting a shaft that is rotatable about an axis. An airfoil assembly is supported by the shaft. A first arcuate coil assembly is supported on the structural member and is arranged at least partially about the shaft. A second arcuate coil assembly is supported on the airfoil assembly adjacent to the first arcuate coil assembly and is rotatable relative thereto. One of the coil assemblies provides a magnetic field having an inductance with an electronic message. The inductance of the one coil assembly produces a voltage containing the message in the other coil assembly. The message may be demodulated from the voltage. In this manner, messages may be sent to and from airfoil assembly systems such as blade heaters and blade pitch actuators.

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Wethersfield, CT, United States of America

Robert D Klapatch