CH715145A2 - Thermoelectric watch testable in production or after-sales service. - Google Patents

Abstract

The invention relates to a thermoelectric watch (1) comprising: a thermoelectric generator (10); a voltage booster (20) connected to said thermoelectric generator (10); an energy management circuit (30) connected to said voltage booster (20) and configured to manage the charge of at least one energy storage element (40), said energy management circuit (30) comprising an output (HR_LOW) configured to pass from a first logic state (S1) to a second logic state (S2) when said thermoelectric generator (10) starts generating electrical energy, and to pass from the second logic state (S2) in the first logic state (S1) when said thermoelectric generator (10) completes the generation of electrical energy. at least one capacitor (CI) coupled to a load (Q) configured to emit a signal (Sq) detectable by a measuring device, when the output (HR_LOW) goes from one logic state to another.

Description

Description

Technical Field [0001] The invention relates to a thermoelectric watch comprising a thermoelectric generator, a voltage booster connected to said thermoelectric generator and an energy management circuit connected to said voltage booster and configured to manage the charge of at least an energy storage element.

Technological background In the field of thermoelectric watches, it is known to a person skilled in the art to use a thermoelectric generator which makes it possible, from body heat, to supply electrical energy to a watch when the latter is on the wrist. Since the thermoelectric generator produces a low voltage, a voltage booster increases the voltage produced so as to obtain a voltage large enough to supply an energy management circuit. The energy management circuit makes it possible to charge at least one storage element such as a battery so as to supply a motor of the thermoelectric watch even when the conditions for generating thermoelectric energy are no longer met.

A drawback is that in production or in after-sales service, an operator cannot know whether the thermoelectric generation is active or inactive.

Claims (14)

SUMMARY OF THE INVENTION The aim of the present invention is to overcome the drawback mentioned above. 1. Thermoelectric watch (1) comprising: - a thermoelectric generator (10), - a voltage booster (20) connected to said thermoelectric generator (10), - an energy management circuit (30) connected to said voltage booster (20) and configured to manage the charge of at least one energy storage element (40), said energy management circuit (30) comprising an output (HFLLOW) configured to pass from a first logic state (S1) to a second logic state (S2) when said thermoelectric generator (10) starts generation of electrical energy, and to pass from the second logic state (S2 ) in the first logic state (S1) when said thermoelectric generator (10) completes the generation of electrical energy, characterized in that it further comprises at least one capacitor (C1) connected to said energy management circuit (30) , coupled to a load (Q) and configured for: - undergo a load variation (dQ) when said output (HFLLOW) of said energy management circuit (30) passes either from the first logic state (S1) to the second logic state (S2), or from the second logic state (S2) in the first logical state (S1), - supplying said load with current (Q) when it undergoes said load variation (dQ), said load (Q) being configured to emit a signal (Sq) detectable by a measuring device (AT) when it is traversed by said current. 1) Light emitting diode LED emitting in the infrared spectrum The light emitting diode LED is configured to emit an infrared signal IR when it is traversed by the charge or discharge current I of said capacitor C1. In this way, the user, thanks to an AT measuring device, can detect the infrared signal IR emitted and therefore detect the start or stop of the generation of electrical energy by the thermoelectric generator 10. In a first nonlimiting embodiment illustrated in FIG. 3a, the energy management circuit 30 is connected to a single capacitor C1 itself coupled to a light-emitting diode LED. Watch 1 thus includes only one LED light-emitting diode. The nonlimiting example of FIG. 3a illustrates a light-emitting diode LED which is a load Q arranged according to FIG. 2a. The light-emitting diode LED operates through an upward or downward transition of the HR_LOW output. By means of the light-emitting diode, it is possible to detect either the start or the completion of the generation of electrical energy by the thermoelectric generator 10. In a nonlimiting embodiment, said at least one capacitor C1 is connected in series to a resistor R1. Resistor R1 is connected in parallel with said at least one light-emitting diode LED. The resistor R1 allows a slow and progressive discharge of said capacitor C1 after each upward or downward transition of the HR_LOW output, namely when the light-emitting diode no longer conducts. It will be noted that, in a nonlimiting example, the resistor R1 leads the capacitor C1 to discharge from 90 to 99% in 5 and 10 seconds between each transition. The RC time constants are thus typically located between 5 and 10 seconds. The capacitor C1 discharges so as to obtain a zero potential difference across its terminals. In a nonlimiting embodiment illustrated in FIG. 3b, the AT measuring device configured to detect the infrared signal IR comprises a photodiode Pd and an amplifier A. Thus, when the AT measuring device is near watch 1, it detects the infrared signal IR using an optical coupling which is created between the photodiode Pd and the infrared diode IR of the watch 1. The measuring device AT is for example a photo-detector. In a second nonlimiting embodiment illustrated in FIG. 3c, the energy management circuit 30 is connected to two capacitors C1, C1 'each coupled respectively to a light-emitting diode LED1, LED2. Watch 1 thus comprises two light-emitting diodes LED1, LED2. The nonlimiting example of FIG. 3c illustrates two infrared diodes LED1, LED2 which are charges Q1, Q2 respectively arranged according to FIG. 2b and operating according to what has been described for FIG. 2b. Thanks to the two infrared diodes LED1, LED2, it is possible to detect the start and also the completion of the generation of electrical energy by the thermoelectric generator 10. The light emitting diodes LED1, LED2 are configured to emit infrared signals IR1, IR2 of wavelengths X1, 12 different. In a nonlimiting embodiment, said capacitor C1 is connected to a resistor R1 and said capacitor C1 'is connected to a resistor R1'. The resistor R1 is connected in parallel with said at least one light-emitting diode LED1 and the resistor R1 'is connected in parallel with said at least one infrared diode LED1'. Resistor R1 allows a slow and progressive discharge of said capacitor C1 after each downward transition of the HFLLOW output, namely when the light-emitting diode LED1 no longer conducts. The resistor R1 'allows a slow and progressive discharge of said capacitor C1' after each rising transition of the HR_LOW output, namely when the light-emitting diode LED2 no longer conducts. In a nonlimiting embodiment not shown, the measuring device AT is configured to detect the infrared signal IR1 and the infrared signal IR2 using two photodiodes Pd and two amplifiers A, the two photodiodes Pd being fitted with optical filters making them sensitive to the two respective wavelengths λ1, λ2 so as to detect the respective infrared signals IR1 and IR2. It is technically possible to take a similar approach by replacing infrared LEDs with ultraviolet LEDs, and to have a measuring device sensitive to UV wavelengths, provided that the powers emitted are harmless. 1) a light emitting diode emitting in the infrared spectrum (illustrated in FIGS. 3a and 3c), 2. Thermoelectric watch (1) according to the preceding claim, according to which said charge (Q) is a light emitting diode (LED) configured to emit an infrared (IR) or ultraviolet signal. 2) LC oscillating circuit The LC oscillating circuit is configured to emit an RF radio frequency signal when it is traversed by the charge or discharge current I of said capacitor C1. In this way, the user, thanks to an AT measuring device, can detect the radiofrequency signal RF emitted and therefore detect the start or stop of the generation of electrical energy by the thermoelectric generator 10. In a first nonlimiting embodiment illustrated in FIG. 4a, the energy management circuit 30 is connected to a single capacitor C1 itself coupled to an oscillating circuit LC. Watch 1 thus only includes an LC oscillating circuit. The nonlimiting example of FIG. 4a illustrates an oscillating circuit LC which is a load Q arranged according to FIG. 2a. The oscillating circuit LC generates an RF radio frequency signal of a certain frequency f when it is excited by a positive or negative electric pulse. It therefore works thanks to an upward transition or a downward transition of the HR-LOW output. By means of the LC oscillating circuit, it is possible to detect either the start or the completion of the generation of electrical energy by the thermoelectric generator 10. In a nonlimiting embodiment illustrated in FIG. 4b, the AT measuring device configured to detect the radiofrequency signal RF comprises an oscillating circuit L'C 'tuned to the frequency f, a rectifier bridge PT and an amplifier A. Thus, when the AT measuring device is located near watch 1, it detects the radiofrequency signal RF thanks to an inductive coupling between its oscillating circuit L'C 'and the oscillating circuit LC of watch 1. The oscillating circuit L'C' is tuned to the same frequency as the oscillating circuit LC. The rectifier bridge PT generates a DC voltage representative of the envelope of the radio frequency signal RF, which is a damped oscillation at high frequency. In a nonlimiting embodiment, the radiofrequency signal RF is situated in a frequency range going from 100 Hz to 100 kHz. In a second nonlimiting embodiment illustrated in FIG. 5c, the energy management circuit 30 is connected to two capacitors C1, C1 'each coupled respectively to an oscillating circuit LC1, LC2. Watch 1 thus comprises two oscillating circuits LC1, LC2. The nonlimiting example of FIG. 5c illustrates two oscillating circuits LC1, LC2 which are loads Q1, Q2 respectively arranged according to FIG. 2b and operating according to what has been described for FIG. 2b. Thanks to the two oscillating circuits LC1 and LC2, the start and also the completion of the generation of electrical energy by the thermoelectric generator 10 are detected. The oscillating circuits LC1, LC2 are configured to transmit radiofrequency signals RF1, RF2 of frequencies f1, f2 different. In a nonlimiting embodiment not shown, the measuring device AT configured to detect the radiofrequency signal RF1 and the radiofrequency signal RF2 comprises two oscillating circuits L'C ', two rectifier bridges PT and two amplifiers A, the two oscillating circuits L'C 'being tuned to the two respective frequencies f1, f2 so as to detect the respective radiofrequency signals RF1 and RF2. A variant of this mode implements an RC oscillator instead of an LC oscillator. 2) an oscillating circuit LC coil / capacitor (illustrated in figs. 4a and 4c), or RC resistance / capacitor, 3. Thermoelectric watch (1) according to claim 2, according to which a resistor (R1) is connected in parallel with the light-emitting diode (LED). 3) TE electromechanical transducer The TE electromechanical transducer is configured to emit an acoustic signal AC when it is traversed by the charge or discharge current I of said capacitor C1. In this way, the user, thanks to an AT measuring device, can detect the acoustic signal AC emitted and therefore detect the start or stop of the generation of electrical energy by the thermoelectric generator 10. In a first nonlimiting embodiment illustrated in lafig. 5a, the energy management circuit 30 is connected to a single capacitor C1 itself coupled to the electromechanical transducer TE. Watch 1 thus only includes an electromechanical TE transducer. The nonlimiting example of FIG. 5a illustrates an electromechanical transducer TE which is a load Q arranged according to FIG. 2a. The TE electroacoustic transducer operates through an upward or downward transition of the HR_LOW output. By means of the electromechanical transducer TE, it is possible to detect either the start or the completion of the generation of electrical energy by the thermoelectric generator 10. In a nonlimiting embodiment illustrated in FIG. 4a, the electromechanical transducer TE comprises a coil L which cooperates with a flexible ferromagnetic blade FM excited by the coil L. When the coil L is crossed by the current i, it emits an electromagnetic field. The flexible ferromagnetic FM blade vibrates under the effect of the electromagnetic field and transmits its vibration to the back F of watch 1. This generates an acoustic signal AC. The FM ferromagnetic flexible blade can vibrate at the resonance frequency r. In a nonlimiting embodiment, the acoustic signal AC is in a frequency range from 100 Hz to 100 kHz. In a nonlimiting embodiment illustrated in FIG. 5b, the AT measuring device configured to detect the acoustic signal AC comprises a microphone Ml and an amplifier A. Thus, when the AT measuring device is near watch 1, it detects the acoustic signal AC by means of an acoustic coupling between the microphone Ml and the bottom F of watch 1, the microphone Ml detecting the vibration of the flexible ferromagnetic blade FM which is transmitted to the bottom F of watch 1. In a second nonlimiting embodiment illustrated in FIG. 5c, the energy management circuit 30 is connected to two capacitors C1, C1 'each coupled respectively to an electromechanical transducer TE1, TE2. Watch 1 thus comprises two electromechanical transducers TE1, TE2. The nonlimiting example of FIG. 5c illustrates two electromechanical transducers TE1, TE2 which are charges Q1, Q2 respectively arranged according to FIG. 2b and operating according to what has been described for FIG. 2b. Thanks to the two electromechanical transducers TE1, TE2, it is possible to detect the start and also the completion of the generation of electrical energy by the thermoelectric generator 10. The electromechanical transducers TE1, TE2 are configured to emit acoustic signals AC1, AC2 at different resonance frequencies r1, r2. For this purpose, they each comprise a flexible ferromagnetic blade FM1, FM2 of different size which can each vibrate at a resonant frequency r1, r2. In a nonlimiting embodiment not illustrated, the measuring device AT configured to detect the acoustic signal AC1 and the acoustic signal AC2 comprises two microphones Ml and two amplifiers A, the microphones Ml being tuned to the two resonant frequencies r1, r2 respective so as to detect the acoustic signals AC1 and AC2 respectively. A variant of this mode implements the blade of the electromechanical transducer described in order to strike a counterpart under the effect of the action of the coil, and it is this shock which is measured by the measuring device, in addition to the vibration of the blade. 3) an electromechanical TE transducer (illustrated in figs. 5a and 5c), 4. Thermoelectric watch (1) according to claim 1, according to which said load (Q) is an oscillating circuit (LC) configured to emit a radio frequency (RF) signal. 4) L coil [0119] The L coil is configured to emit a magnetic field EM when it is traversed by the charge or discharge current i of said capacitor C1. In this way, the user, thanks to an AT measuring device, can detect the emitted magnetic field EM and therefore detect the start or stop of the generation of electrical energy by the thermoelectric generator 10. The nonlimiting example of FIG. 6a illustrates a coil Lqui which is a load Q arranged according to FIG. 2a and operating according to what has been described for FIG. 2a. The coil L works thanks to an upward transition and a downward transition of the HFLLOW output. Thus, by means of the coil, the start and the end of the generation of electrical energy by the thermoelectric generator 10 are detected. In a nonlimiting embodiment illustrated in FIG. 6b, the AT measuring device is configured to detect the magnetic field EM using a coil L ′. Thus, when the measuring device AT is close to watch 1, it detects the electromagnetic signal EM thanks to a magnetic coupling between its coil L'and the coil L of watch 1. The polarity of the induced voltage being sensitive to the polarity of the derivative of the magnetic field emitted, it is possible to distinguish the start and the end of the generation of electrical energy by the thermoelectric generator 10, with a single transmission and detection channel, namely with a single and even coil L. It is possible to replace the current and the coil L, by a voltage and a capacitor, and detect the electric charge of the capacitor with the appropriate measuring device. It will be noted that the amplifier A included in the various measurement devices AT described in the case of the load Q 1) to 4) makes it possible to amplify the different signals Sq detected. Thus, the AT measuring devices adapted to the different loads Q make it possible to detect the activity of the thermoelectric generator 10. Watch 1 can therefore be tested in production, once the watch has been assembled. Watch 1 can also be tested in after-sales service. The various charges Q and the associated AT measuring devices described have a limited cost. Consequently, the detection is simple to perform and is of limited cost. • Third nonlimiting embodiment [0125] As illustrated in FIG. 7, the thermoelectric watch 1 includes: - a thermoelectric generator 10, - a voltage booster 20, - an energy management circuit 30, - at least one capacitor C1. The thermoelectric watch 1 further comprises: - an energy storage element 40, a motor 50 configured to set in motion the hands and dial (s) (not shown) of the thermoelectric watch 1, - a resonator 60 configured to serve as the frequency base for the thermoelectric watch 1. The description of these elements with reference to the first and second embodiment is to be applied in this third non-limiting embodiment. [0128] As illustrated in FIG. 7, the thermoelectric watch 1 further comprises a conductive element F. The capacitor C1 and the conductive element F are described below. ° C1 capacitor [0130] As illustrated in lafig. 7, the capacitor Ci is electrically connected to the conductive element F, itself connected to the input impedance Z of the measuring device AT. Thus, the capacitor Cl is connected by one of its terminals to the energy management circuit 30 and by the other of its terminals to the conductive element F. In a nonlimiting embodiment, the capacitor C1 is configured to charge when said HFLLOW output of said energy management circuit 30 passes from the high state S1 to the low state S2 and vice versa. In a nonlimiting variant, the capacitor C1 is configured for: - load when said HR_LOW output of said energy management circuit 30 passes from high state S1 to low state S2, namely when said output HRJJDW is in downward transition. This corresponds to the start of generation of electrical energy by the thermoelectric generator 10 (the latter becomes active), - also charge when said HR_LOW output of said energy management circuit 30 goes from low state S2 to high state S1, namely when said HR_LOW output is in rising transition. This corresponds to the completion of the generation of electrical energy by the thermoelectric generator 10 (the latter becomes inactive). In one example, the thermoelectric generator 10 becomes active when watch 1 is put on the user's wrist and becomes inactive when watch i is no longer worn on the user's wrist. In another example, the thermoelectric generator 10 becomes inactive when watch 1 is in direct sunlight with a dark dial which absorbs energy from the sun. Even if it stays on the wrist, the middle of watch 1 becomes hotter than the wrist. The thermoelectric generator 10 can stop several times during the day. It is estimated that he can stop and become active at most a hundred times a day. o Conductive element F [0136] In a nonlimiting embodiment, the conductive element F is the back of watch 1. The back F of watch 1 is easily accessible, an AT measuring device can thus easily cooperate with the back F of watch 1. In a nonlimiting embodiment, the conductive element F is made of oxidized aluminum. In a nonlimiting embodiment, the conductive element F is thermally insulated. This allows a flow of heat from the wrist to be mainly channeled to the thermoelectric generator 10 to allow good generation of electrical energy by the watch 1. The thermal insulation is done by means of a thermal insulator I. In the case of the back F of watch 1, in a non-limiting embodiment, the thermal insulator I is a plastic ring which surrounds said back F. In a nonlimiting embodiment, the conductive element F is also electrically isolated from the middle part K of the watch 1 by means of the thermal insulator I. This makes it possible to avoid a short circuit with the middle part K of watch 1. Thus the conductive element F is electrically floating so that it can serve as a contact electrode for the measuring device AT. Thus, the back F of watch 1 is used as a measurement terminal. Thanks to this contact electrode, the electrical charges will be able to be transferred from the conductive element F to the AT device. [0141] As illustrated in FIG. 8, the conductive element F is in contact with the measuring device AT. The AT measuring device has an input impedance Z, an amplifier A, a measuring tip P1 and a ground tip M1. The impedance Z has a high value which makes it possible to measure a voltage pulse corresponding to the transfer of a small quantity of electrical charges. The bottom F of watch 1 thus makes it possible to transfer electrical charges by capacitive coupling with the AT measuring device. The electric charges will indeed move in the bottom F of watch 1, the bottom F then acting as a capacitor. Thus, during a downward transition corresponding to the start of the generation of electrical energy by the thermoelectric generator 10, and during an upward transition corresponding to the completion of the generation of electrical energy by the thermoelectric generator 10, electrical charges are transferred from the capacitor C1 to the bottom F then from the bottom f to the measuring device AT. The measuring tip P1 is in contact with the bottom F of watch 1 and allows the transfer of electrical charges. The ground tip M1 makes it possible to ground the middle part K of the watch 1. The charging current I of the capacitor C1 can thus flow in a closed circuit which comprises the bottom F, the impedance Z and the middle K. Thus, the measuring device AT coupled to the bottom F makes it possible to detect the activity of the thermoelectric generator 10. Watch 1 can therefore be tested in production, once the watch has been assembled. Watch 1 can also be tested in after-sales service. The capacitor C1 as well as the associated AT measuring device described have a limited cost. Consequently, the detection is simple to perform and is of limited cost. Of course, the present invention is not limited to the examples illustrated but is susceptible to various variants and modifications which will appear to a person skilled in the art. Thus, in another nonlimiting embodiment, the various charges Q can generally be connected to any static potential other than + Vbat and -Vbat. claims 4) a coil L (illustrated in fig. 6a). Dual, the coil can be replaced by a capacitor for capacitive detection. The different embodiments of the charge Q are presented below. 5. Thermoelectric watch (1) according to claim 1, according to which said load (Q) is an electromechanical transducer (TE) configured to emit an acoustic signal (AC). To this end, according to a first aspect, the invention relates to a thermoelectric watch according to claim 1. 6. Thermoelectric watch (1) according to claim 1, according to which said charge (Q) is a coil (L) configured to emit an electromagnetic field (EM), or a capacitor configured to emit an electrostatic field. [0006] Thus, as we will see in detail below, when the energy management output changes from one state to another state (via an upward or downward transition), it is possible, by different couplings ( optical, acoustic, capacitive, inductive, radio frequency) between the load and a test device, to know when the thermoelectric generation is activated or deactivated. 7. thermoelectric watch (1) according to any one of claims 1 to 5, according to which said thermoelectric watch (1) comprises two capacitors (C1, ΟΓ) connected to said energy management circuit (30), each coupled to a load (Q1, Q2), one of the capacitors (C1) being configured to: - undergo a load variation (dQ) when said output (HR_LOW) of said energy management circuit (30) goes from the first logic state (S1) to the second logic state (S2), - supply current to the load (Q1) to which it is coupled when it undergoes said load variation (dQ), said load (Q1) being configured to emit a signal (Sq) detectable by a measuring device (AT) when 'it is traversed by said current (I), the other of the capacitors (C1') being configured for: - undergo a load variation (dQ) when said output (HR_LOW) of said energy management circuit (30) goes from the second logic state (S2) to the first logic state (S1), - supply current to the load (Q2) to which it is coupled when it undergoes said load variation (dQ), said load (Q2) being configured to emit a signal (Sq ') detectable by the measuring device (AT ) when it is traversed by said current (! '). According to non-limiting embodiments of the invention, the thermoelectric watch can have the characteristics of claims 2 to 10, taken alone or in all technically possible combinations. 8. Thermoelectric watch (1) according to claim 7, according to which the charges (Q1, Q2) are light-emitting diodes (LEDI, LED2) configured to emit infrared signals (IR1, IR2) of wavelengths (M, 12 ) different. According to a second aspect, the invention relates to a thermoelectric watch according to claim 11. 9. thermoelectric watch (1) according to claim 7, according to which the charges (Q1, Q2) are oscillating circuits (LC1, LC2) configured to emit radiofrequency signals (RF1, RF2) of different frequencies (f 1, f2) . [0009] Thus, as we will see in detail below, when the energy management output changes from one state to another state (via an upward or downward transition), it is possible, by detection of the potential conductive element by means of a test device, to know when the capacitor is charging and thus when the thermoelectric generation is activated or deactivated. 10. Thermoelectric watch (1) according to claim 7, according to which the charges (Q1, Q2) are electromechanical transducers (TE1, TE2) configured to emit electroacoustic signals (AC1, AC2) of resonance frequencies (r1, r2) different. According to non-limiting embodiments of the invention, the thermoelectric watch can have the characteristics of claims 12 to 15, taken alone or in all technically possible combinations. Brief description of the figures The invention will be described below in more detail with the aid of the appended drawings, given by way of non-limiting examples, in which: fig. 1 schematically represents a thermoelectric watch according to a first nonlimiting embodiment of the invention, said thermoelectric watch comprising a voltage generator, a voltage booster, and an energy management circuit, FIG. 2a represents the energy management circuit of FIG. 1 connected with a single capacitor, itself coupled to a load, according to the first embodiment, FIG. 2b represents the energy management circuit of FIG. 1 connected with two capacitors, each coupled to a load, according to a second nonlimiting embodiment of the invention, FIG. 3a represents the energy management circuit and the capacitor of FIG. 2a, said capacitor being coupled to a charge which is a light emitting diode emitting in the infrared spectrum, according to a first non-limiting variant of the first embodiment, FIG. 3b shows a measuring device configured to measure an infrared signal emitted by said light-emitting diode of FIG. 3a, using a photo-detector, fig. 3c represents the energy management circuit and the two capacitors of FIG. 2b, said capacitors each being coupled to a load which is a light emitting diode emitting in the infrared spectrum, according to a first non-limiting embodiment of the second embodiment, FIG. 4a represents the energy management circuit and the capacitor of FIG. 2a, said capacitor being coupled to a load which is an oscillating circuit, according to a second non-limiting variant of the first embodiment, FIG. 4b shows a measuring device configured to measure a radio frequency signal emitted by said oscillating circuit of FIG. 4a, fig. 4c represents the energy management circuit and the two capacitors of FIG. 2b, said capacitors each being coupled to a load which is an oscillating circuit, according to a second non-limiting variant of the second embodiment, FIG. 5a represents the energy management circuit and the capacitor of FIG. 2a, said capacitor being coupled to a load which is an electromechanical transducer, according to a third non-limiting variant of the first embodiment, FIG. 5b shows a measuring device configured to measure an acoustic signal emitted by said electromechanical transducer of FIG. 5a, fig. 5c represents the energy management circuit and the two capacitors of FIG. 2b, said capacitors each being coupled to a load which is an electromechanical transducer, according to a third non-limiting variant of the second embodiment, FIG. 6a represents the energy management circuit and the capacitor of FIG. 2a, said capacitor being coupled to a load which is an inductor, according to a fourth non-limiting variant of the first embodiment, FIG. 6b shows a measuring device configured to measure an electromagnetic signal emitted by said inductor of FIG. 6a, fig. 7 schematically represents a thermoelectric watch according to a second embodiment of the invention, said thermoelectric watch comprising a voltage generator, a voltage booster, and an energy management circuit according to a third nonlimiting embodiment of the invention, fig. 8 represents the energy management circuit of FIG. 7 connected with a capacitor, itself connected to a conductive element. Detailed description of the invention The identical elements, by structure or by function, appearing in different figures keep, unless otherwise specified, the same references. 11. Thermoelectric watch (1) comprising: - a thermoelectric generator (10), - a voltage booster (20) connected to said thermoelectric generator (10), - an energy management circuit (30) connected to said voltage booster (20) and configured to manage the charge of at least one energy storage element (40), said energy management circuit (30) comprising an output (HR_LOW) configured to pass from a first logic state (S1) to a second logic state (S2) when said thermoelectric generator (10) starts generating electrical energy, and to pass from the second logic state (S2) in the first logic state (S1) when said thermoelectric generator (10) completes the generation of electrical energy, characterized in that it further comprises: - a capacitor (C1) connected to said energy management circuit (30), configured to charge when said output (HRJ-OW) of said energy management circuit (30) goes from the first logic state (S1) to the second logic state (S2) or vice versa; - a conductive element (F) electrically connected to the capacitor (C1). 12. Thermoelectric watch (1) according to claim 11, according to which said conductive element (F) is the back of the watch. 13. Thermoelectric watch (1) according to any one of the preceding claims, according to which the management circuit (30) comprises a push-pull amplifier stage. The thermoelectric watch 1 is described according to a premierei a second nonlimiting embodiment illustrated in FIGS. 1 to 6b, then according to a third nonlimiting embodiment illustrated in FIGS. 7 and 8. • First and second nonlimiting embodiments [0014] As illustrated in FIG. 1, the thermoelectric watch 1 includes: - a thermoelectric generator 10; - a voltage booster 20; - an energy management circuit 30; - at least one capacitor C1. The thermoelectric watch 1 further comprises: - an energy storage element 40; - A motor 50 configured to set in motion the hands and dial (s) (not shown) of the thermoelectric watch 1; - a resonator 60 configured to serve as the frequency base for the thermoelectric watch 1. In the following description, the thermoelectric watch 1 is also called watch 1. The elements of watch 1 are described in detail below. o Thermoelectric generator 10 The thermoelectric generator 10 is configured to produce electrical energy, namely a low voltage, of the order of a few millivolts (mV) from the heat of the human body when watch 1 is on a user's wrist. In a nonlimiting example, the voltage is between 6 and 12 mV. Note that the generation of electrical energy normally takes less than a second when watch 1 is put on the wrist. Thus, the thermoelectric generator 10 becomes active when the watch is worn on the wrist. The thermoelectric generator 10 makes it possible to start watch 1 when the latter's battery is discharged. As the thermoelectric generators are known to those skilled in the art, the thermoelectric generator 10 is not described in detail here. The thermoelectric generator 10 is connected to the voltage booster 20. o Voltage booster 20 The voltage booster 20 is configured to increase the voltage generated by the thermoelectric generator 10 so as to obtain a voltage large enough to supply the energy management circuit 30. This voltage is l 'order of the Volt. In a nonlimiting example, it is equal to 2.5 V. The voltage booster 20 is connected to the energy management circuit 30. The voltage generated is found on an input VDD_SOL of said energy management circuit 30. Thus, a voltage greater than or equal to a threshold (2.5 V in the nonlimiting example described), means that the thermoelectric generator 10 has become active, in other words that it has started a generation of electrical energy. The voltage boosters being known to those skilled in the art, the voltage elevator 20 is not described in detail here. o Energy management circuit 30 and energy storage element 40 [0025] The energy management circuit 30 is configured to manage the charge of at least one energy storage element 40. In a nonlimiting embodiment, the energy management circuit 30 is a programmable microcontroller configured to charge said at least one energy storage element 40. In a nonlimiting embodiment, the management circuit 30 includes a push-pull amplifier stage so as to obtain rising and falling transitions on the HFLLOW output described below, with a certain capacity for delivering current, typically 1 to 2 mA in a nonlimiting embodiment. As illustrated in FIG. 1, the energy management circuit 30 notably comprises: - a VDDJSOL entry, - a HFLLOW output, - a VSUP output, - a VDD_LTS output, - a VDDJSTS output. Thanks to the voltage received on its VDDJSOL input, the energy management circuit 30 can supply said at least one energy storage element 40. In a nonlimiting example, said at least one energy storage element 40 is a Bat battery. The Bat battery is used to power, for example, the motor 50 of watch 1 even when there is no longer any thermoelectric energy generation. In a non-limiting embodiment, the energy management circuit 30 is configured to manage the charge of two energy storage elements 40. Each energy storage element 40 is connected to the management circuit d energy 30 via the respective outputs VDD_LTS and VDDJSTS. In a non-limiting embodiment, a first energy storage element 40 is a short-term energy storage element ("Short Term Storage" in English) and a second energy storage element 40 is an element of long term energy storage ("Long Term Storage" in English). In a nonlimiting example, the short-term energy storage element is a capacitor referenced C5 in FIG. 1, and the long-term energy storage element is a rechargeable battery referenced Bat in FIG. 1. In a nonlimiting example, the Bat battery is a Lithium-Ion battery. The capacitor C5 and the battery Bat are taken as nonlimiting examples in the following description. In a non-limiting embodiment, said energy management circuit 30 is configured to alternately manage the charge of the capacitor C5 and of the battery Bat so as to supply, for example, the motor 50 of said watch 1. At this indeed, it further includes a plurality of switches (not shown). Thus, the energy management circuit 30 begins by charging, via its input VDD_SOL, the capacitor C5 which charges in a few seconds (typically between 3 to 5 seconds depending on the product experience targeted). Then, when the latter is charged (it has reached a sufficient voltage, between 1.5 V and 3 V for example), the energy management circuit 30 disconnects the capacitor C5 from its input VDD_SOL and it charges via its input VDD_SOL the Bat battery which charges more slowly in a few hours or even a few days, until it reaches a sufficient voltage, between 1.5 V and 3 V for example. While the Bat battery is charging, the capacitor C5 discharges at the output VSUP, which allows to power the motor 50 of watch 1 and thus start the movement of watch 1. The capacitor C5 discharge indeed in seconds. The Bat battery takes over from the capacitor C5 to supply the motor 50. The Bat battery also discharges on the output VSUP which makes it possible to supply the motor 50 of watch 1 for a few months. The Bat battery can indeed take a few months to discharge. When the capacitor C5 and the battery Bat have each reached a respective sufficient voltage, the energy management circuit 30 connects the two in parallel. Thus, when the thermoelectric generator 10 is active, the electrical energy generated by the thermoelectric generator 10 arrives at the VDDJSOL input, which makes it possible to charge the capacitor C5 and the Bat battery. When the thermoelectric generator 10 is inactive, that is, it no longer generates electrical energy, the capacitor C5 and the battery Bat are disconnected from the input VDD_SOL. The thermoelectric generator 10 becomes inactive when, for example, watch 1 is in thermal equilibrium and is no longer worn on the wrist. When it is put on the wrist again, the alternating management of the charge of the capacitor Cl and of the Bat battery described above resumes. The HR__LOW output of the energy management circuit 30 is configured for: - go from a first logic state S1 to a second logic state S2 when the thermoelectric generator 10 starts generating electrical energy, and - Go from the second logic state S2 to the first logic state S1 when said thermoelectric generator 10 completes the generation of electrical energy. The HR_LOW output thus makes it possible to signal the activity of the thermoelectric generator 10. In the following, it will be understood that the first logic state S1 is a high state, and the second state S2 is a low state. However, it could be the reverse. In a nonlimiting embodiment, the high state S1 is at the potential + Vbat and the low state S2 is at the potential -Vbat. Thus, the HR_LOW output is in an upward transition when it goes from the low state S2 to the high state S1 and is in a downward transition when it goes from the high state S1 to the low state S2. More particularly, the HR_LOW output is configured for: - Go from the high state S1 to the low state S2 when said thermoelectric generator 10 begins generation of electrical energy; - Go from the low state S2 to the high state S1 when said thermoelectric generator 10 completes a generation of electrical energy. The low state of the HR_LOW output means that the thermoelectric generator 10 is active. The high state of the HR-LOW output means that the thermoelectric generator 10 is inactive. It is estimated that, during normal use, the HR_LOW output cannot have more than a hundred rising and / or falling transitions per day. A hundred transitions per day corresponds to an average current of less than 0.1 microamps through the capacitor C1 mentioned below, which represents a small percentage of consumption of watch 1, less than 10%. The energy management circuit 30 is connected to said at least one capacitor C1 described below. o Capacitor C1 [0051] As illustrated in FIGS. 1,2a and 2b, said at least one capacitor C1 is coupled to a charge Q, and is configured for: - undergo a load variation dQ when said HR_LOW output of said energy management circuit 30 passes from a state S1, S2 to another state S2, S1, - supplying said load Q with current when it undergoes said load variation dQ. The current which feeds the load Q is equal to dQ / dt. The charge of a capacitor being expressed by Q = C * U, we have Q1 = C1 * Vbat at most in the nonlimiting example taken, and dQ = + or - Q1. The capacitor C1 is connected in series with said load Q. Thus, the capacitor C1 is connected to one of its terminals to the energy management circuit 30 and to the other of its terminals to the load Q. When the capacitor C.1 undergoes a charge variation dQ, the charge or discharge current, otherwise called current I, necessary for its charge or discharge, flows transiently in the charge Q allowing it to emit a signal Sq detectable by an AT measuring device. It will be noted that after an upward or downward transition of the HFLLOW output, when said HR_LOW output remains in one of the two states S1, S2, there is no current I flowing in the load Q. Thus, the load Q does not consume in steady state but only during the rising and falling transitions. Its average potential is Uq = 0. The current I which flows through the charge Q is in fact a current pulse since it is produced only when the capacitor C1 undergoes a charge variation dQ, namely during the rising or falling transitions of the HFLLOW output. The intensity of this current pulse is of the order of a milliampere. In a nonlimiting example, it is between 1 and 10 mA. Note that the intensity of the current pulses typically drops to 10% after a period of less than 50 milliseconds. Thus, the signal Sq emitted by the charge Q does not last long, for a duration typically less than 50 milliseconds. • First embodiment In a first nonlimiting embodiment illustrated in FIG. 2a, said energy management circuit 30 is connected to a single transmission circuit, formed by a capacitor C1 and a load Q. Said capacitor C1 is coupled to the load Q, itself connected to + Vbat in this example, and is configured for: - charge when said HFLLOW output of said energy management circuit 30 goes from high state S1 to low state S2, namely when said HFLLOW output is in downward transition; and or - discharge when said HFLLOW output of said energy management circuit 30 goes from low state S2 to high state Si, ie when said HFLLOW output is in rising transition. > Downward transition The charge of the capacitor C1 during the downward transition of the HFLLOW output corresponds to the start of generation of electrical energy by the thermoelectric generator 10. The current I necessary for the charge of the capacitor C1 passes through the charge Q which then emits a signal Sq. The change of state of the HRJJDW output thus causes the emission of a signal Sq by the load Q. Thus, when the thermoelectric generator 10 starts generating energy (it becomes active), the load Q emits a signal Sq which is detectable by a measuring device AT. The user thus sees, via the measuring device AT, that the thermoelectric generator 10 has just started, that is to say it has just started generating electrical energy. Note that the user is in a nonlimiting example, an operator who tests watch 1 in production or in after-sales service. In a variant of the non-limiting example cited, the thermoelectric generator 10 becomes active when watch 1 is put on the user's wrist. Watch 1 indeed comes into contact with the heat of the human body. After the downward transition, when the HR_LOW output remains in the low state S2 (the thermoelectric generator 10 is always active), the value of the current I which flows in the load Q rapidly drops to zero. Consequently, the AT measuring device no longer detects a signal Sq. It will be noted, in the example cited, that the signal Sq emitted is detectable by the measuring device AT a few seconds after the thermoelectric watch 1 has been placed on the wrist or on an adequate fitting, once the short-term energy storage element C5 is charged with the electrical energy produced by the thermoelectric generator 10. Rising transition In the example cited and its variant, the discharge of the capacitor C1 during the rising transition of the HR-LOW output corresponds to an interruption in the generation of electrical energy by the thermoelectric generator 10. The current I necessary for the discharge of the capacitor C1 passes through the charge Q which then emits or does not emit a signal Sq, depending on whether it is configured or not to emit a signal in the two current polarities. In the case where the charge Q makes it possible to generate a signal Sq in the two current polarities, an upward transition of the output HRJ-OW also causes the emission of a signal Sq. Thus, when the thermoelectric generator 10 completes a generation of energy (it becomes inactive), the load Q can also emit a signal Sq which is detectable by an AT measuring device. The user thus sees, via the AT measurement device, that the thermoelectric generator 10 has just stopped working, that is, it has completed the generation of electrical energy. Note that the user is in a nonlimiting example, an operator who tests watch 1 in production or in after-sales service. In a nonlimiting example, the thermoelectric generator 10 becomes inactive when the watch 1 is no longer worn on the user's wrist. Watch 1 is no longer in contact with the heat of the human body and thus tends towards thermal equilibrium at the terminals of the thermoelectric generator. In another nonlimiting example, the thermoelectric generator 10 becomes inactive when the watch 1 is in direct sunlight with a dark dial which absorbs energy from the sun. Even if it stays on the wrist, the middle of watch 1 becomes hotter than the wrist. The thermoelectric generator 10 can stop several times during the day. It is estimated that, during normal use, the thermoelectric generator 10 can stop and become active again at most a hundred times a day. After the rising transition, when the HFLLOW output remains in the high state S1 (the thermoelectric generator 10 is always inactive), the value of the current i which flows in the load Q rapidly drops to zero. Consequently, the AT measuring device no longer detects a signal Sq. It will be noted that the signal emitted Sq, detectable by the measuring device AT, appears after a few seconds to a few minutes, depending on the thermal conditions, after watch 1 has been removed from the wrist, duration which corresponds to time that the back of watch 1 which has been warmed by the heat of the human body to cool. Note that FIG. 2a illustrates the charge Q connected to the positive terminal + Vbat of the battery Bat. However, in another nonlimiting embodiment not illustrated, the charge Q could be connected to the negative terminal -Vbat of the battery Bat or any other static potential. Thus, the negative or positive electrical pulse observed on the potential Uq of the charge Q is a reflection of the downward or upward transitions of the HFLLOW output of the energy management circuit 30. Depending on this positive electrical pulse or negative, the charge Q emits the signal Sq depending on whether it was designed for a unipolar or bipolar action. Thus, the measuring device AT can detect the rising and falling transitions of said HFLLOW output through the signal Sq emitted and therefore can detect the start or the end of the generation of electrical energy from the thermoelectric generator 10. • Second embodiment In a second nonlimiting embodiment illustrated in FIG. 2b, said energy management circuit 30 is connected to two separate transmission circuits, each formed by a capacitor C1, CT coupled to a load Q1, Q2. One of the capacitors is configured to undergo a charge variation dQ when said HRJLOW output goes from the high state S1 to the low state S2, and the other of the capacitors is configured to undergo a charge variation dQ when said HR_LOW output goes from low state S2 to high state S1. Thus, in a nonlimiting alternative embodiment, the capacitor C1 is configured for: - load when said HR_LOW output goes from high state S1 to low state S2, and supplying current to the load Q1 to which it is coupled when it charges, said load Q1 being configured to emit a signal Sq detectable by a measuring device AT when it is traversed by the charging current i of said capacitor C1, Furthermore, the capacitor C1 'is configured for: - discharge when said HR_LOW output goes from low state S2 to high state S1, and - supplying current to the load Q2 to which it is coupled when it discharges, said load Q2 being configured to emit a signal Sq 'detectable by the measuring device AT when it is traversed by the discharge current i' of said capacitor C1 '. Thus, the charge current i necessary to charge the capacitor C1 flows in the charge Q1, and the discharge current i 'necessary to charge the capacitor C1 ′ flows in the charge Q2. Thus, the load Q1 emits a signal Sq1 when the thermoelectric generator 10 begins generation of electrical energy and the load Q2 emits a signal Sq2 when the thermoelectric generator 10 completes a generation of electrical energy. In a nonlimiting embodiment, the charge Q1 is connected to the positive terminal of the battery + Vbat and the charge Q2 is connected to the negative terminal of the battery -Vbat. It is noted that the charges Q1 and Q2 can also be connected to any other static potential. Thus, the user of watch 1 can detect with a measurement device AT, via the signals Sq1, Sq2 emitted, the start and stop of the generation of electrical energy by the thermoelectric generator 10. It will be noted that a signal Sq1 is detectable by an AT measuring device after a few seconds after watch 1 has been placed on the wrist or on an adequate fitting, once the energy storage device C5 was charged with the electrical energy produced by the thermoelectric generator 10. It will be noted that the signal emitted Sq2, detectable by the measuring device AT, appears after a few seconds to a few minutes, depending on the thermal conditions, after watch 1 has been removed from the wrist, duration which corresponds to time that the back of watch 1 which has been warmed by the heat of the human body to cool. o Charge Q As described above, the charge Q is configured to emit a detectable signal Sq when it is traversed by the charge or discharge current i of said capacitor C1. According to the type of charge described below, it will be sensitive to an uplink transition, to a downward transition or both, namely it will only emit a signal Sq during an uplink transition, only during a downward transition, or during an upward transition and a downward transition. In nonlimiting embodiments, the charge Q is: 14. Thermoelectric watch (1) according to any one of the preceding claims, according to which said energy management circuit (30) is configured to alternately manage the charge of two energy storage elements (40) so as to supply a motor (50) of said thermoelectric watch (1).