Detection system for mailbags - uses thin magnetic strip or wire markings for triggering operation or selective processing and uses AC coil sensors (NL 20.9.77)

摘要

The detector system identifies objects masked with thin magnetic strips or wires which trigger the operation and provide selective processing. The magnetic strip or wire is detected when passing through a detection zone in the automatic sorting of parcels or post-bags. One or more frames (4) support an AC supplied excitation coil (6) which produces an alternating magnetic field and a detector coil (7) thus balanced. In the absence of an object close to the frame, no signal is triggered. If an object bearing a magnetic strip or wire passes through or near the frame (4) a signal is applied to the detector.