Abstract: The smart battery includes an electronic circuit for managing the supply voltage connected to a battery. The electronic circuit includes a battery end-of-life detector, a management unit, an oscillator stage, a DC-DC converter powered on when the supply voltage of the battery is close or equal to a battery end-of-life threshold, and a data or command communication interface. The data or command communication interface is a 1-wire interface which is connected to a positive supply voltage terminal of the smart battery for transmitting a modulated data or command signal through one of the supply voltage terminals. The modulated signal transmitted by the interface may include battery end-of-life information.

Abstract: The smart battery includes an electronic circuit for managing the supply voltage connected to a battery. The electronic circuit includes a battery end-of-life detector, a management unit, an oscillator stage, a DC-DC converter powered on when the supply voltage of the battery is close or equal to a battery end-of-life threshold, and a data or command communication interface. The data or command communication interface is a 1-wire interface which is connected to a positive supply voltage terminal of the smart battery for transmitting a modulated data or command signal through one of the supply voltage terminals. The modulated signal transmitted by the interface may include battery end-of-life information.

Abstract: The invention concerns a method of verifying the proper working of a transponder mounted on a rotating mobile element of a vehicle, characterized in that it includes the steps of: a) measuring a temperature value by means of a temperature sensor connected to the transponder; b) detecting breach of a overheat threshold; c) a monitoring operation carried out by a reader arranged in the vehicle and provided for communicating with the transponder, consisting in executing a command on one of the temperature sensitive elements of the transponder; d) the reader determining the state of the transponder as a function of the response or absence of any response to the command to be executed: (i) if the response is correct, the transponder is operational; (ii) if the response is incorrect, or in the absence of any response, the transponder is not operational.

Abstract: The invention relates to an optical movement detection device including a light source (10) for irradiating a surface (12), a power supply (14) and an optical sensor (16) for sensing light reflected from the surface (12). In order to avoid unused optical energy, it is proposed that the optical movement detection device further comprises at least one solar-cell photodiode (30a-30d), wherein the solar-cell photodiode (30a-30d) is arranged so as to recycle optical energy generated by the light source (10).

Abstract: The invention concerns a method of verifying the proper working of a transponder mounted on a rotating mobile element of a vehicle, characterized in that it includes the steps of: a) measuring a temperature value by means of a temperature sensor connected to the transponder; b) detecting breach of a overheat threshold; c) a monitoring operation carried out by a reader arranged in the vehicle and provided for communicating with the transponder, consisting in executing a command on one of the temperature sensitive elements of the transponder; d) the reader determining the state of the transponder as a function of the response or absence of any response to the command to be executed: (i) if the response is correct, the transponder is operational; (ii) if the response is incorrect, or in the absence of any response, the transponder is not operational.

Abstract: A method for extending battery life in an optical pointing device powered by one or more battery cells (30), the optical pointing device including an optical motion sensing device (10) for tracking motion with respect to a surface (S) and comprising motion sensing circuitry (12) coupled to an optical sensor (15) and at least one light source (14) for illuminating a portion of the surface. The method comprises the steps of (i) monitoring the power output of the said one or more battery cells (30), (ii) detecting when the said power output falls below a certain threshold indicative of a low battery status (EOL) and (iii) upon detection of the low battery status, switching the optical pointing device into a low power consumption mode where power consumption of the optical pointing device is reduced and performance of the optical motion sensing device is partially degraded. An optical pointing device implementing this method.

Abstract: There is disclosed a system for detecting the passage of persons or objects through an entry-exit (4) to a delimited space (2), including (i) a detection device including transmission means (8) for transmitting different first and second electromagnetic signals (a, b) in respectively first and second communication regions (A, B) spatially separated from each other and partially overlapping, (ii) portable electronic units (40) intended to be fitted to said persons or objects and including reception means for said first and second electromagnetic signals, and (iii) means for detecting the direction of passage, through said entry-exit, of a person or an object fitted with a portable electronic unit.

Abstract: The active transponder is intended for several applications or to operate in various modes requiring different levels of security. Security is controlled by varying the maximum communication distance to a reader. The active transponder includes a battery (2) powering the various electronic circuits amplifying component (8), a module (4) forming a demodulator for the incoming signals, and a component for validating the data comprised in the signals, and a data processing unit (10). The unit includes circuit (12) for controlling the maximum communication distance between the transponder and a reader transmitting signals at a determined power. Circuit (12) sends a security signal (S1, S2) respectively to the data validating component and/or to the signal amplifying component. This signal is used either to control the value of the reference value of the validating component, or to vary the gain of the amplifying component to vary the maximum communication distance.

Abstract: There is described a method for extending battery life in an optical pointing device powered by one or more battery cells (30), the optical pointing device including an optical motion sensing device (10) for tracking motion with respect to a surface (S) and comprising motion sensing circuitry (12) coupled to an optical sensor (15) and at least one light source (14) for illuminating a portion of the surface. The method comprises the steps of (i) monitoring the power output of the said one or more battery cells (30), (ii) detecting when the said power output falls below a certain threshold indicative of a low battery status (EOL) and (iii) upon detection of the low battery status, switching the optical pointing device into a low power consumption mode where power consumption of the optical pointing device is reduced and performance of the optical motion sensing device is partially degraded. There is also described an optical pointing device implementing this method.

Abstract: There is described a method of providing indication of low battery status of a battery-powered pointing device designed for detecting motion and outputting motion reports representative of the detected motion, the method comprising the steps of detecting low battery status of the pointing device and affecting output of the motion reports, upon detection of the low battery status, by adding determined and/or pseudo-random components of motion to the motion reports.

Abstract: The invention relates to a method for keyless unlocking of an access door to a closed space, in particular a motor vehicle, which is carried out by an electronic system, comprising a control module for an electronic lock, associated with the door and a portable transponder for authorised users. The method comprises sending an interrogation signal at low frequency from the control module to the transponders and also the exchange of data at high frequency. The control module has reception device for the above which are at least continuously in a listening mode. The method is characterised in that the low frequency transmitters are inactive in a preliminary functional mode, the high frequency transmission device in the transponder periodically emits an activation signal for said the transmission device in order that the above are only activated during limited periods, which ensures the reception of an interrogation signal for a transponder entering the low frequency communication region.

Abstract: The invention relates to a method for keyless unlocking of an access door to a closed space, in particular a motor vehicle, which is carried out by means of an electronic system, comprising a control module for an electronic lock, associated with the said door and a portable transponder for authorised users. The method comprises sending an interrogation signal at low frequency from the control module to the transponders and also the exchange of data at high frequency. The control module has reception means for the above which are at least continuously in a listening mode. Said method is characterised in that the low frequency transmitters are inactive in a preliminary functional mode, the high frequency transmission means in the transponder periodically emits an activation signal for said transmission means in order that the above are only activated during limited periods, which ensures the reception of an interrogation signal for a transponder entering the low frequency communication region.

Abstract: There is disclosed a system for detecting the passage of persons or objects through an entry-exit (4) to a delimited space (2), including (i) a detection device including transmission means (8) for transmitting different first and second electromagnetic signals (a, b) in respectively first and second communication regions (A, B) spatially separated from each other and partially overlapping, (ii) portable electronic units (40) intended to be fitted to said persons or objects and including reception means for said first and second electromagnetic signals, and (iii) means for detecting the direction of passage, through said entry-exit, of a person or an object fitted with a portable electronic unit.

Abstract: Transponder (2) associated with a communication system for various different applications having different security levels. This transponder includes means (18, 26, 40, R) allowing the maximum communication distance between the transponder and a reader (4) to be varied as a function of the application selected or activated. A code, which determines the opening or closing of the switch (40) is associated with each application. In a first group of embodiments, the equivalent impedance of the electronic unit associated with the antenna (6) is varied, whereas in another embodiment, the electric characteristics of the antenna itself are varied.

Abstract: System for communication between a plurality of transceivers, transmitting in particular at a high frequency and arranged respectively in a plurality of delimited spaces each having at least one entrance, and portable electronic units fitted with means for radio-communication with the plurality of transceivers, in particular with a view to detecting each of them penetrating one of the delimited spaces. The communication between the transceivers and the portable electronic units for neighboring delimited spaces is effected at different exclusive frequencies or frequencies of sub-sets of frequencies associated with the exclusive frequencies.

Abstract: System for communication between a plurality of transceivers, transmitting in particular at a high frequency and arranged respectively in a plurality of delimited spaces each having at least one entrance, and portable electronic units fitted with means for radio-communication with said plurality of transceivers, in particular with a view to detecting each of them penetrating one of said delimited spaces. The communication between the transceivers and the portable electronic units for neighbouring delimited spaces is effected at different exclusive frequencies or frequencies of sub-sets of frequencies associated with said exclusive frequencies.

Abstract: The active transponder is intended for several applications or to operate in various modes requiring different levels of security. Security is controlled in particular by varying the maximum communication distance to a reader. The active transponder includes a battery (2) used for powering the various electronic circuits. It further includes amplifying means (8), a module (4) forming a demodulator for the incoming signals and means for validating the data comprised in said signals, and a data processing unit (10). The unit (10) includes a circuit (12) for controlling the maximum communication distance between the transponder and a reader transmitting signals at a determined power. This circuit (12) sends a security signal (S1, S2) respectively to the data validating means and/or to the signal amplifying means. This signal is used either to control the value of the reference value of the validating means, or to vary the gain of the amplifying means to vary the maximum communication distance.

Abstract: This microsystem enables a phenomenon, whose evolution over time is random, to be analyzed. It comprises means for reducing its consumption of energy which acts via a modification of the operating features of the microsystem, the effect of this modification being the passage of said microsystem from an active state to at least one other state, for example a stand-by state. A phenomenon detecting device (30 to 50) generates a representative signal (V.sub.out) which represents the evolution of the phenomenon over time. The representative signal is provided for utilization at an output terminal (37). The microsystem also comprises a threshold circuit (36) connected to the detecting device (30 to 35) and the output terminal (37) for subjecting the representative signal (V.sub.out) to a comparison with a predetermined threshold and for generating a corresponding comparison signal ("mod").

Abstract: The present invention relates to a reference voltage source in CMOS technology. The reference voltage source is based on the use of two compatible bipolar transistors (T1) and (T2) working at different current densities. A transresistance amplifier (1) connected as a negative feedback between the collectors and bases of (T1) and (T2) delivers the reference voltage (V.sub.ref). A conductor block (4) allows sufficient current to be drawn through the resistors (2) and (3) to render neglible the base current of (T1).