Ambient electromagnetic field compensating magnetic pick-up circuit for integrated drive generators

摘要

This invention relates to a magnetic pick-up circuit for use in integrated drive generators of the type employed on board aircraft for power generation. Prior art magnetic pick-up circuits failed to compensate for interference due to operation within an ambient electromagnetic field or failed to preserve the ambient electromagnetic field. The magnetic pick-up circuit includes in combination a first coil responsive to an ambient electromagnetic field and a modulated flux field and a second coil responsive to the ambient electromagnetic field connected to the first coil in opposition to thereby insure that a signal induced by the ambient electromagnetic in the first coil is cancelled by a signal induced by the ambient electromagnetic field in the second coil. Means for providing an output signal representative of modulation of the modulated flux field are coupled to the first coil and the second coil. This output signal is free from distortion due to the ambient electromagnetic field.