Electronic keyboard musical instrument - includes induction coil to generate control signal to regulate output note dependent on key actuation

摘要

A key mechanism for electronic musical instruments enables the amplitude of the generated signal to be dependent upon the way in which the hey is actuated. The instrument is thus given a 'touch' facility. The key consists of a plastics section (1) attached to an actuating section (2) of a magnetic material that is spring biased (5) and supported of a section at the rear. The key is retained at the front against a felt pad (13) attached to the signal generating section (12). The note is generated by switching contacts contained in a housing (15) at the rear and with a main contact (18) actuated by a rod (14) coupled to the key. A 'U'-shaped ferro-magnetic stage is formed by coils (37) on a core (26) and a permanent magnet (28). The emf generated in the induction coil is indicative of the key actuation mode and is used to regulate the note.