Abstract: An angular speed measuring device includes an oscillator for producing an excitation signal which induces mechanical vibrations in a rotating tuning fork, and an analog processing circuit for processing an electrical detection signal derived from the tuning fork. The analog processing circuit comprises a temperature-independent phase shifter responsive to the excitation signal for producing two signals in quadrature. The quadrature signals are applied to two multipliers which also receive the detection signal. The output signals from the multipliers are dependent on the fixed phase shift .phi. between the excitation signal and the detection signal, which is fixed for a given tuning fork, and on the variable phase shift .psi. which is a function of the rotational speed of the tuning fork, but the multiplier output signals are independent of temperature. After A/D conversion, the multiplier output signals are processed in a microprocessor to determine the angular speed.

Abstract: A timepiece which includes a case (2), a horometric movement (4) housed within the case (2) and means for broadcasting an electromagnetic signal including electronic means (12) for furnishing the signal and at least one broadcasting antenna (14) coupled to the electronic means (12). Such timepiece is characterized in that the antenna (14) is arranged on a first face (20a) of a support plate (20) of basically planar form arranged in the interior of the case (2), such antenna (14) being constituted by a thin metallic layer deposited on the face (20a) of the support plate (20). This timepiece is applicable to the control of an arrangement, for example for latching and unlatching, of a door in particular.

Abstract: A method for measuring the distance e separating two faces (3, 4) of an object (1) employs the ultrasonic wave diffused back by said faces and received by a sensor (6). Following digitalization (11), the temporal signal is transformed (12) into a frequency spectrum. The modulus of the frequency spectrum is established (13) then the logarithmic derivative thereof is calculated (15) from whence there results a useful signal including a periodic signal onto which a linear signal is superposed. Following suppression (14, 16) of the linear signal the useful signal is applied (17) to a frequency window in order to eliminate the noise therefrom. The signal thus obtained is inversely transformed (18) to obtain a signal the amplitude of which is a function of the time and the envelope of this latter signal is determined (19). After having determined the temporal spread .DELTA.t separating the time origin from the envelope peak showing the greatest amplitude, the distance e is calculated from the relation e=c.multidot.

Abstract: An echo tracker clamps a time window for detecting an echo at the position of an echo produced by a mobile wall receiving an ultrasonic pulse signal at a repetition rate F.sub.r. It includes a depth counter (28) which counts in order to define the beginning of the time window in relation to a pulse of the pulse signal and which when it reaches a given value, supplies an enabling signal to activate authorization means (30) and a position detector (32).Enabling means (30) provide an enabling signal for a given time which defines the detecting time window. During this time, the position detector counts until the echo is detected. The value reached at that instant is used to clamp again the time window and to modify the initial value of the depth indicator.The invention is useful in the medical field for measuring the changes of the position of an interface between two tissues.