Key operation sensors and evaluation circuit, e.g. for vehicle or office door key

摘要

Display device (1) to display locking status of key-actuated lock is fixed to body of key (4). Device contains vertical turning sensor (9), horizontal turn sensor (15), activating device, torque sensors (26), a current source and activating unit (20).Turning sensors (9,15) are realised by `fall' channels (12) where switching contacts (S1, S3) are closed by a conducting ball in the channel. Horizontal turn sensors have a bend or nick in which the conducting ball lodges between excursions. Torque sensors are piezoelectric.