Horological movement equipped with an oscillator comprising a piezoelectric balance-spring

An horological movement comprising an analogue time display, a geartrain, a barrel kinematically linked with the analogue display via the geartrain, and an oscillator formed of a resonator, comprising a balance and a piezoelectric balance-spring, and a mechanical escapement coupling the balance with the geartrain, the piezoelectric balance-spring being formed at least partially from a piezoelectric material and comprising at least two electrodes of which at least one electrode is connected to an electronic control circuit, the piezoelectric material and said at least one electrode being arranged in such a way as to enable the application, managed by the electronic control circuit, of electrical stress on the piezoelectric balance-spring, the horological movement being configured such that the barrel is capable of driving the analogue display and maintaining alone a functional oscillation of the oscillator with a first amplitude which is dependent on the spatial orientation of the horological movement;

• wherein the electronic control circuit is arranged to be able to be connected to an electrical energy source and to be able to control the application of an electrical voltage to said at least one electrode so as to generate driving electrical pulses for the oscillator which supply it with sufficient energy to enable a functional oscillation of said oscillator, for each spatial orientation of the horological movement, with a second amplitude which is greater than a maximum nominal value of the first amplitude for said spatial orientation.