Abstract: The invention concerns a non acoustic alarm device, intended to be fitted to a unit worn in contact with the body, such as a timepiece or a portable telephone, including a case, a moving mass within said case intended to transmit vibrations thereto, a coil (L) electromagnetically coupled to said moving mass to cause it to oscillate, and an excitation circuit of said coil. According to the invention, the device includes means for measuring the instantaneous oscillation frequency of the coil-moving mass unit during the oscillation in progress, as well as means for generating a series of excitation pulses for said coil during the following oscillation, whose characteristics are a function of the measurement of said instantaneous oscillation frequency. Due to its high yield and low energy consumption, this device is particularly suitable for watches.

Abstract: A detection device has a transducer (10) for emitting and receiving series of ultrasonic pulses. An integrator (23) integrates echo signals resulting from ultrasonic pulses within a time window so as to produce an integral value. A time-delay circuit (28) is used to control the instant of opening T1 of a time window and a control circuit (25) determines an average value of a number of n integral values and for loading the values of the opening a instant T1 into the time-delay circuit (28) so as to maintain the average value at a steady value. The control circuit (25) determines the average value by loading a first value of T1 in the time-delay circuit before the integration of the first x echo signal and a second value of T1 in the time-delay circuit before the integration of the second n-x echo signals.

Abstract: The invention concerns a method for exciting and monitoring a piezoelectric motor (M1) in stepping mode, the motor having a resonance frequency (f.sub.R) and being supplied electrically at an excitation frequency (f.sub.E) during each operating step.The method is characterized in that it comprises a monitoring phase which extends at least over several successive steps of said motor and in which, for a present step of said motor, a determined excitation frequency value (f.sub.E +1) is used, the duration (t.sub.E +1) of the present step is measured, said duration (t.sub.E +1) is compared to the duration (t.sub.E) of the preceding step and, according to the result of this comparison, said excitation frequency value (f.sub.E +2) is corrected for the following step in a direction tending to reduce the duration of the step.A circuit is also described which enables the implementation of the method.

Abstract: An ultrasonic detection device having a transducer (10) for emitting and receiving ultrasonic pulses through a windshield, and producing an echo signal (40,50) representative of the reflected pulses. The detection device also includes an amplifier (23) for amplifying the echo signals (40,50) by a selectable gain, an integrating circuit (26) for integrating each of the echo signals (40,50) during a selected time period (62,63) so as to produce an integral value, amplifier control circuitry (27,28) measuring the integral value and selecting the gain of the amplifier so as to maintain the integral value at a steady-state value, and the temporal deviation of the integral value from the steady-state value is measured to determine if it is greater than a predetermined threshold value. The invention may be used to detect water on a windscreen and to control the operation of a windscreen cleaning system.

Abstract: The invention concerns a diagnostic circuit for amperometrically determining the current passing through a sensor (41). The circuit comprises a current source (V+, 46) for passing a constant DC current through said sensor (41), switching means (45) for selectively operating said current source, comparing means (42) for comparing the potential difference (V.sub.BS) across said sensor to a reference voltage (V.sub.ref), and producing a control signal (D) control means (44) for controlling said switching means (45) in response to said control signal (D), and timing means (48,49) for measuring the cumulative time during which said switching signal (Q) has said first logic level during a selected time interval, so as to provide an output signal (50) indicative of a mean value of current (I.sub.bs ave) passing through said sensor (41).

Abstract: The hands of the timepiece are connected to a barrel spring which also drives the rotor of a generator at a speed greater than a desired speed Vc. The electric energy supplied by the generator energizes a slaving circuit that includes a transistor which short-circuits the coil of the generator and thus brakes the rotor down to a speed less than the desired speed Vc when a comparator indicates that this rotor is ahead with respect to its theoretical angular position. A limiting circuit limits the duration of the braking action of the rotor to a fraction of the period of the a.c. voltage supplied by the generator. This arrangement ensures that the slaving circuit is adequately energized even if the rotor is substantially ahead.

Abstract: The device comprises a piezoelectric transducer, a primary battery, and a circuit which applies a control voltage to the transducer or which short-circuits the latter depending on the state of a control signal. The control voltage is produced by a voltage increasing circuit comprising a coil, a diode and a capacitor constituted by the transducer, that are connected in series, in that order, across the terminals of the primary battery, and an oscillator responsive to the control signal to control a transistor in such a manner that it either alternately produces and cancels a short circuit across the terminals of the circuit formed by the diode and the transducer or is permanently blocked. A second transistor is also responsive to the control signal to short-circuit the transducer when the first transistor is blocked. The device is simpler, cheaper and consumes less electrical power than known devices.

Abstract: An optical cell having an optically active material, for example a liquid crystal is disclosed, the transparency of which is a function of the electrical voltage applied together with a control circuit, wherein said optically active material presents an electrical impedance variable with the frequency of the signal applied and said control circuit has a voltage source and means for controlling the frequency of the signal delivered by said voltage source. The cell has applications in attenuating light, notably in a sun screen or automobile rear-view mirror.

Abstract: A processing circuit is provided for signals (S.sub.1, S.sub.2) supplied by two transducers measuring a physical quantity parameter in a differential mode and delivering a signal representative of this parameter. This processing circuit essentially comprises a first counter for counting within a measurement period an integer N.sub.1 of periods T.sub.1 of the signal S.sub.1, a second counter for counting within this period of measurement an integer N.sub.2 of periods T.sub.2 of the signal S.sub.2, and a logic circuit to deliver a signal S.sub.m representative of the difference between the interval N.sub.1 .multidot.T.sub.1 and the interval N.sub.2 .multidot.T.sub.2, this signal being representative of the value of the physical parameter. The circuit is useful for measuring acceleration, force, pressure or temperature.

Abstract: A device for displaying the value of a quantity represented by input data comprises a mobile indicator member (24) driven by a stepping motor (20), a control circuit (18) for this motor for delivering drive pulses to the motor in response to the input data to move the indicator member to a position corresponding to the value of the quantity, and a dial (26) for showing an indexing system, for example a scale, which cooperates with the indicator member to indicate the value at least approximately. The dial comprises a liquid crystal, electrochromic or electroluminescent electrooptical display device (26) which displays the indexing system in response to signals from another control circuit (28) when the latter receives an activation signal. The device enables values of a single quantity situated in different ranges or values of distinct quantities to be indicated, by making the cell selectively display corresponding indexing systems. A specific application of the device is for automobile dashboards.

Abstract: The invention concerns a device for measuring a physical quantity, for example a force (A), and providing an output signal (Vs) whose amplitude represents the measured value. The device comprises a first oscillator (1) including a resonator (3) to which the force (A) is applied, this oscillator delivering a first alternating signal (S1) whose frequency depends on the magnitude of the force (A), a second oscillator (2) supplying a second alternating signal (S2) whose frequency is determined by the amplitude of the output signal (Vs), an EXCLUSIVE OR gate (20) receiving the first and second signals, and a low-pass filter (21) delivering the output signal (Vs) in response to a signal supplied by the gate (20). The amplitude of this output signal depends on the phase difference of the first and second signals, and constitutes a measurement of the magnitude of the applied force (A). The device is advantageously used when the measurement is to be displayed in analog form.

Abstract: The present invention comprises measuring, upon application of a drive pulse to the actuating coil 5 of the stepping motor, the variation in the magnetic induction flux in the stator of the motor, and interrupting the drive pulse when the variation in flux reaches a predetermined value. Measurement of the variation in flux may be effected, for example, by detecting the current in the actuating coil and integrating the difference between the supply voltage of the actuating coil and the product of the current by the d.c. resistance of the coil, or by providing an auxiliary detection coil 71 and integrating the voltage induced therein in an integrator 73, 74. When the integrator outputs exceeds the magnitude of either a positive or negative reference voltage, a comparator circuit 78, 79, 81 provides the signal to a circuit 13 to terminate the drive pulse.

Abstract: An electronic watch comprising a stepping motor for driving a mechanism for displaying the time information, a quartz oscillator, a frequency divider with an adjustable division factor, a circuit for adjusting the division factor, a memory containing data relating to the magnitude of said adjustment and a logic circuit which, in response to an interrogation signal, produces a measuring signal which is supplied to the coil of the stepping motor and which comprises pulses whose distribution is representative of the division factor and the frequency of the oscillator and whose duration is sufficiently short so as not to cause the motor to turn and sufficiently long to cause a magnetic stray field of the coil of the motor which can be detected by an external apparatus for measuring the rate of the watch.

Abstract: A circuit for producing a numerical signal representative of the value of the physical parameter which is to be displayed and which can assume a given number of values. The signal is applied to a decoder for controlling the display cell.The decoder is so arranged as to render visible a single display element for certain values of the numerical signal and two adjacent elements for other values. The cell therefore comprises a small number of display elements than there are different values to be displayed.

Abstract: An electronic measuring apparatus for measuring the rate of an analog-display electronic watch which comprises a quartz oscillator, a frequency divider with an adjustable division factor, a stepping motor and a circuit which, when the stem of the watch is pulled, produces a measuring signal emitted by the stray field of the coil of the stepping motor and comprising trains of pulses whose period and content are respectively representative of the frequency of the oscillator and the division factor. The measuring apparatus comprises a pick-up means for detecting said measuring signal, circuits for computing the rate of the watch and means for displaying said rate.

Abstract: In an electronic watch, the content of the memory associated with the adjusting circuit of the division ratio of the frequency divider is modified at each correction of the display to compensate for the frequency error of the crystal oscillator and to thereby reduce the running error of the watch. Such electronic watches use a crystal oscillator whose frequency is not optimum. To compensate for the frequency variations due to manufacturing tolerances, age and temperature, correction circuits are incorporated into such watches. When an operator acts on a switch on the case of the watch to correct the time display indication, the content of the memory is modified to correct for the frequency error of the crystal oscillator.

Abstract: A frequency divider divides a sonic or ultrasonic time base frequency to provide signals with a frequency of N/60 Hz, where N is a whole number comprised between 1 and 16. These signals drive a motor step-by-step, the motor in turn driving minutes and hours hands by one step per pulse. A liquid crystal supplied with a signal of optically perceptible frequency of about 1 Hz can be added, providing a flashing optical display enabling verification of running of the watch.

Abstract: The hands of the timepiece are connected to a barrel spring which also drives the rotor of a generator at a speed greater than a desired speed Vc. The electric energy supplied by the generator energizes a slaving circuit that includes a transistor which short-circuits the coil of the generator and thus brakes the rotor down to a speed less than the desired speed Vc when a comparator indicates that this rotor is ahead with respect to its theoretical angular position. A limiting circuit limits the duration of the braking action of the rotor to a fraction of the period of the a.c. voltage supplied by the generator. This arrangement ensures that the slaving circuit is adequately energized even if the rotor is substantially ahead.