Piezoelectric balance spring, and method for manufacturing the balance spring

Abstract

The piezoelectric balance spring (3) is provided for a circuit (10) for self-regulating an oscillation frequency of an oscillating mechanical system (2, 3), or an energy recovery circuit or a motor circuit for actuating the movement or for the automatic maintenance thereof. The piezoelectric balance spring (3) comprises at least one piezoelectric layer (7, 7′, 17, 17′, 27, 27′) disposed on a top face (20) or bottom face of a certain number of coils of the spring in a plane, and at least two pairs of electrodes (8a, 8b, 8c, 8d), whereby the electrodes of each pair are disposed on two opposing faces of the same piezoelectric layer or respectively two piezoelectric layers so as to apply a reverse bias voltage on each pair of electrodes.

Dependencies are inferred from the claim text.