Phase-Locked Frequency Multiplier for the Signal Averaging of the Vibration of the Wessex Helicopter Input Spiral Bevel Pinion

摘要

This Australian report provides details of the design of a phase-locked frequency multiplier for the conversion of a signal derived from the alternator of the Wessex helicopter into a pulse train suitable for controlling the sampling and signal averaging by a computer of the vibration of the input spiral bevel pinion in the Wessex main rotor gearbox. The frequency multiplier is implemented as a series of four phase-locked loops, and features an oscillator which maintains the loops at approximately the correct frequency in standby mode thereby reducing the time to lock when the input signal is applied.