Piezo-electric resonant vibrator for selective call receiver

摘要

A piezo-electric resonant vibrator is described comprising a resonant armature having a centrally located weight, and at least four planar circular spring members which provide a restoring force normal to the movement of the weighted armature within a non-magnetic housing which encloses and supports the armature. A piezo-electric driver is coupled to the armature for inducing movement of the armature at a predetermined resonant frequency. A ferromagnetic plate is mounted to the housing and magnetically couples to a magnet which is coupled to the weight to maintain tension on the armature when an excitation signal is not supplied to the piezo-electric driver, and the armature is at equilibrium.