Abstract: The electromechanical escapement device is associated with an electronic circuit having a quartz oscillator and calculation means suitable for calculating the difference between the period of the quartz oscillator and the period of a mechanical oscillator and releasing an escape wheel, normally controlled by said mechanical oscillator, when the difference between said periods is greater than a threshold value.

Abstract: The invention concerns a device for indicating the state of watch batteries. Said device comprises, in combination: a circuit for determining (34) at least a physical characteristic of the cell (10) which varies when it is nearly discharged, a circuit for metering (36) the power consumed by the watch, a circuit for assessing (40) the capacity rating of the battery, connected to the determining (34) and metering (36) circuits and designed to process data and select the most relevant information derived either from the determining circuit (34), or from the metering circuit (36), means for displaying the state of the battery (38,40,42), and a circuit controlling (39) the display means.

Abstract: A horological piece includes a display (10) comprising a recurring cycle indicator (13) driven by an independent motor (11) and having a supplementary display position (14) at which a sign representative of the state of charge of an energy source controlling the display, is provided. The horological piece further includes a detection circuit (2, 16) adapted to, firstly, during the detection of a predetermined level of charge of the energy source, control the display so that the recurring cycle indicator is moved the required number of steps to display the representative sign and, secondly, jump the supplementary position during the normal operation of the horological piece.