Abstract:
A method and system for measuring a physical parameter, such as speed and/or distance travelled by a bicycle, includes a permanent magnet disposed on a front fork and a measuring circuit with a magnetic sensor disposed on a rim of the wheel at the same distance from the wheel axis of rotation as the magnet. The sensor passes in front of the magnet to generate an induced voltage pulse at each passage. The induced voltage is rectified and stored on a capacitor. Energy recovery during the sensor passing in front of the magnet allows powering of the measuring circuit. The parameter is calculated in the calculation unit clocked by an oscillator based on the received induced voltage pulses by knowing the bicycle wheel diameter. Measurements performed from the measuring circuit are transmitted to a portable device carried by the user or mounted on the bicycle to be displayed.
Abstract:
A method for providing information about a mechanical wristwatch, including the following steps, performed by the wristwatch: harvesting an intermittently available external energy, storing the harvested energy, at the end of a predefined period of time, generating an analysis report on an activity of the owner of the wristwatch, based at least on the times and durations of availability of the external energy, when or after the harvested energy quantity reaches a threshold, the threshold being on or above an energy level required to power a transmission unit of the wristwatch, wirelessly transmitting the analysis report to a distant reader with the transmission unit.
Abstract:
The synchronous demodulator electronic circuit for phase modulation signals includes, in a control loop, a discrete Fourier transform unit for receiving the phase modulation signal to be demodulated, and means of recovering the carrier frequency of the phase modulation signal, so that the discrete Fourier transform unit performs in combination the operations of mixing and low-pass filtering the sampled phase modulation signal with at least one frequency and phase adapted digital conversion signal to supply at least one demodulated signal at the output of the discrete Fourier transform unit.
Abstract:
A transmitter-receiver includes an electronic chip a mixer for mixing the frequency of a received radio frequency signal with that of an oscillating signal supplied by a first frequency synthesizer in, a switch having two inputs connected to an output of the mixer and to an auxiliary input terminal, a filter and gain stage connected to the output of the switch, and a modulator-demodulator connected to the output of the filter and gain stage. The first frequency synthesizer is connected between the output of the modulator-demodulator and radio frequency input and output terminal, and configured to supply a frequency-modulated signal to the radio frequency input and output terminal. The electronic chip further includes a second frequency synthesizer connected between the output of the modulator-demodulator and an auxiliary output terminal, and configured to synthesize a modulated low-frequency signal supplied by the auxiliary output terminal, whereby the center value of the low frequency is equal to the value of the intermediate frequency.
Abstract:
The method for localizing a beacon consists in transmitting, by a first transceiver, an initiation signal, which is received by second and third transceivers, in calculating, by means of said initiation signal, errors between a reference frequency of the first transceiver and reference frequencies of the second and third transceivers, in transmitting, by the beacon, a first pulsed signal, which is received by the first, second and third transceivers, in transmitting, by the first transceiver, a second pulsed signal, which is received by the second and third transceivers, in calculating differences in the times-of-flight of the first and second pulsed signals, each time-of-flight difference being calculated in a time base provided by a local oscillator of the first transceiver by means of reference frequency errors, and in calculating a beacon position by means of the times-of-flight.
Abstract:
The electronic circuit with a self-calibrated PTAT current reference includes a PTAT current generator dependent on at least one integrated resistor for supplying a PTAT output current. It further includes a reference current generator dependent on at least one switched capacitor resistor, for supplying a reference current. The reference current and the PTAT output current are compared in a comparator so as to digitally adapt the programmable integrated resistor, or to digitally adapt the dimensional ratio of the transistors of a current mirror in the PTAT current generator, to supply the adapted PTAT output current.
Abstract:
The signal receiver has means to suppress at least one higher harmonic component from a MEMS or crystal oscillator having a reference resonator in filtered intermediate signals of a signal receiver. The signal receiver comprises an antenna for receiving electromagnetic signals, a low noise amplifier for amplifying signals received by the antenna, one MEMS or crystal oscillator comprising a reference resonator to generate an oscillating signal with a predefined duty-cycle, a mixer for mixing the amplified and received signals with the oscillating signal to generate intermediate signals, a band-pass filter to filter the intermediate signals, and a duty-cycle controller coupled to the MEMS or crystal oscillator and coupled to the output of the band-pass filter to analyze the spectrum of the filtered intermediate signals and to modify the duty-cycle of the oscillating signal in response to the spectrum analysis of the filtered intermediate signals.
Abstract:
A crystal oscillator and a startup method for initiating operation of a crystal oscillator, the crystal oscillator includes an oscillator structure including a crystal resonator and an electronic oscillator circuit connected to the crystal resonator, the oscillator structure having a first terminal and a second terminal, a startup controller operable to initiate an oscillation in the oscillator structure by exciting the oscillator structure with a sequence of excitation signals derivable from a clock signal and when triggered by a timing signal, the sequence of excitation signals includes at least a first excitation signal and a second excitation signal, a comparator including a first and a second input terminal and an output terminal, the first input terminal being connected to the first terminal and wherein the second input terminal is connected to the second terminal.
Abstract:
For the process for determining a distance, there is provided a succession of coded signals at high frequency transmitted between a base station and a wearable object. A preparation of a response signal is conducted in the wearable object on reception of the first synchronisation signal after activation of the wearable object. A transmission of successive coded signals at high frequency from the wearable object is conducted for the station, of which the last response signal is scrambled by a modulation of data on the last signal received at a high transfer rate from the station. An analysis is conducted in a processing unit of the base station after reception of the signals from the wearable object to accurately determine the distance separating the base station from the recognised wearable object.
Abstract:
The method for calibrating the frequency synthesizer using two-point FSK modulation consists, in a first phase, in supplying an excitation signal generated by a calibration unit to a sigma-delta modulator by deactivating a digital-to-analog converter and transmitting the output signal from a loop filter of the synthesizer to the calibration unit, which digitally converts the incoming signal and offsets the phase shift between the excitation signal and the loop filter output signal in the calibration unit. In a second phase, the excitation signal is supplied to the sigma-delta modulator and to the activated digital-to-analog converter, and the digital-to-analog converter gain is calibrated by checking, in the calibration unit, the polarity of the loop filter output signal with respect to the excitation signal, and using a dichotomy algorithm.