Abstract: Methods and systems for controlling a pneumatic starter air valve of a gas turbine engine are described herein. The starter air valve is controlled in a first mode of operation by actuating a first solenoid of the starter air valve with a steady-state input signal. Passage of the steady-state input signal to a second solenoid of the starter air valve is allowed, to actuate the second solenoid and enable pressure regulation of the starter air valve. The starter air valve is controlled in a second mode of operation by actuating the first solenoid with a pulse-width modulation input signal. Passage of the pulse-width modulation input signal to the second solenoid is prevented, to disable the pressure regulation in the second mode of operation.

Abstract: Methods and systems for controlling a pneumatic starter air valve of a gas turbine engine are described herein. The starter air valve is controlled in a first mode of operation by actuating a first solenoid of the starter air valve with a steady-state input signal. Passage of the steady-state input signal to a second solenoid of the starter air valve is allowed, to actuate the second solenoid and enable pressure regulation of the starter air valve. The starter air valve is controlled in a second mode of operation by actuating the first solenoid with a pulse-width modulation input signal. Passage of the pulse-width modulation input signal to the second solenoid is prevented, to disable the pressure regulation in the second mode of operation.

Abstract: Herein provided are sensing systems, methods, sensors, and methods of manufacturing a sensor for a rotating element in an engine. A magnetic core having first and second ends is positioned with the first end proximate the rotating element. A permanent magnet is positioned proximate the second end of the magnetic core and is configured for subjecting the magnetic core and the rotating element to a magnetic field. A bifilar winding comprising a first wire and a second wire electrically insulated from one another is wrapped around at least a portion of the magnetic core, the bifilar winding configured to generate a first signal in the first wire and a second signal in the second wire in response to rotation of the rotating element relative to the sensor.