Abstract: The device (1) includes a mixer (4) which generates a signal (S4) having a frequency (F4) equal to the difference between two frequencies (F2, F3), which are those of two signals (S2, S3) each generated by a generator (2, 3) and which vary parabolically as a function of the temperature (T) with quadratic coefficients (&bgr;1,&bgr;2) that are different to each other. In order for the frequency (F4) of the signal (S4) generated by the mixer (4) to be at least substantially independent of the temperature (T), the generators (2, 3) are arranged such that the ratio of the quadratic coefficients (&bgr;1,&bgr;2) is equal to the inverse of the ratio of values (F2r, F3r) that the corresponding frequencies (F2, F3) have at a determined temperature (Tr).

Abstract: The device (1) includes a mixer (4) which generates a signal (S4) having a frequency (F4) equal to the difference between two frequencies (F2, F3), which are those of two signals (S2, S3) each generated by a generator (2, 3) and which vary parabolically as a function of the temperature (T) with quadratic coefficients (&bgr;1,&bgr;2) that are different to each other.

Abstract: The invention concerns a method for controlling a continuous rotation miniature motor including a rotor carrying permanent magnets and a stator carrying at least one coil in which an alternating induced voltage is generated when the rotor rotates, this method consisting in maintaining the rotation of said rotor by successive pulses (102) supplied, in respective half periods of the induced voltage (U.sub.i), before the induced voltage reaches a maximum absolute value in each of these half periods. In particular, the time interval (t.sub.1) between a passage through zero of the induced voltage and the beginning of a maintenance pulse (102), provided in the half period following said passage through zero, is constant.

Abstract: A drive device comprises a gearbox (1) of the motorcycle type in which a selector shaft (10), via its angular position, enables the gear ratio in which the gearbox will be engaged to be determined. The device is provided with an electronic control device (DCE) designed to automatically place the gearbox (1), or in other words the selector shaft (10), in the position corresponding to the gear selected by the driver or automatically determined as a function of the speed of the vehicle. The electronic control device (DCE) comprises, in particular, means for down-shifting gently despite the absence of a synchronizer in the gearbox.

Abstract: An energizing circuit for an electric motor, driving a clockwork of a timepiece, includes a stator coil coacting with one or more magnet pairs on an associated rotor whose periodic alignment with the coil induces therein a train of monitoring pulses with a frequency proportional to the motor speed. The monitoring pulses are amplified and fed back to the coil, as driving pulses, through a coincidence gate which is opened or closed under the control of a speed-sensing network including a crystal-controlled oscillator whose output wave, stepped down in a frequency divider, is a series of timing pulses fed to a pulse counter which is reset by the monitoring pulses and whose count, therefore, varies inversely with the motor speed.