Electromagnetic actuator used for keyboard musical instrument

摘要

An electromagnetic actuator unit is provided over a keyboard of a piano, and each of the electromagnetic actuators of the electromagnetic actuator unit has a solenoid coil wound on a bobbin and a plunger for pushing down one of the keys, wherein the gravity exerted on the plunger is smaller than a recovery force of the key or a return spring coupled to the plunger is provided outside of the bobbin for smoothly moving the plunger without influences of the magnetic field produced by the solenoid coil.