Foreign body detector for intake of harvesting machine - has threshold switches in two channels handling signals from metal detector and compression roller position potentiometer

摘要

The signal from an inductive metal detector (1), installed in the intake feed roller opposite the compression roller, is amplified (1V), filtered (1F), rectified (1G) and applied to a threshold switch (1S) which arrests (11) the feed roller when a predetermined threshold of signal is exceeded. Each roller carries a tachometer (3,30) from which a speed signal (GS,GS1) is derived for adjusting the gain of the signal amplifier (1V) and its counterpart (4V) in the positional signal channel. ADVANTAGE - Trigger sensitivity of metal detector is largely independent of quantity and speed of intake of harvested material.