EP1574920B1 - Method for managing the time information display in an electronic device - Google Patents

Description

The present invention relates to a method of managing a display of a time information in an electrical appliance.

It also relates to an electrical device adapted to implement the display management method according to the invention.

In general, the invention relates to electrical appliances equipped with a time display system. Generally, these displays are adapted to indicate the current time, but also the duration of a process implemented in the electrical device, or a programmed duration at the expiration of which the operation of the electrical device will be triggered .

More particularly, the present invention relates to household electrical appliances of the type cooking appliance, including electric oven or microwave oven, or refrigerator. This field of application is of course not limiting.

When several electrical appliances are equipped with a time information display, it is difficult to synchronize the indication of the current time at the display of each device.

In particular, at the time of installation of an electrical device, it is possible to update the current time on each device. The synchronization in time of this display is however difficult to obtain.

The display of a time information on an electrical device is made from information given by a clock built into the electrical device.

The clocks equipping such devices can be classified into two categories: the time-based internal clocks and time-based external clocks, for example generated by the power supply network of the device.

The clocks based on internal time are associated with an embedded time base, that is to say integrated into the electrical device. They can also be associated with a standalone power supply, allowing the operation of the clock independently of the power supply of the device. In a conventional manner, an internal time base may consist of a quartz, or alternatively of a type 555 electronic oscillator.

These clocks based on internal time have the advantage of being inexpensive and allow good accuracy in the time display. However, they generally have a temperature drift of up to 100 ppm for a rise of 50 ° C.

The time-based clocks generated by the power supply network generally use the frequency of the power grid which is relatively stable (plus or minus 20 ppm). Since this frequency of the electrical network is common to all the electrical appliances connected to this network, it is possible, after common initialization, to keep the time display synchronized at the level of each electrical appliance using such an external time clock.

However, in case of power failure, the time information is lost so that it is necessary to update the time at each electrical device and synchronize this update. Moreover, these clocks based on external time do not allow to know the duration of the power failure.

We know in the document DE 8804746 a device that provides, in case of power failure, the replacement of the time generated by an external time base by a time generated by an internal time base.

The object of the present invention is to solve the aforementioned drawbacks and to propose a method of managing a display of time information implemented in an electrical appliance using the electrical network, making it possible to best manage a power failure. electric.

For this purpose, the invention provides a method for managing a display of time information in an electrical apparatus comprising a clock based on internal time and a time-based clock generated by the power supply network of the apparatus.

• détection d'une mise sous tension de l'appareil électrique ;
• lecture d'une information horaire mémorisée dans une horloge à base de temps interne ;
• mise à jour de l'horloge à base de temps générée par le réseau d'alimentation électrique par l'information horaire mémorisée dans l'horloge à base de temps interne ; et
• affichage de ladite information horaire de l'horloge à base de temps générée par le réseau d'alimentation électrique.

According to the invention, this management method comprises the following steps:

• detecting a power-up of the electrical apparatus;
• reading a time information stored in an internal time clock;
• updating the time-based clock generated by the power supply network with the time information stored in the internal time-based clock; and
• displaying said time information of the time-based clock generated by the power supply network.

This management method thus makes it possible, during the powering up of an electrical apparatus, to obtain an automatic display of a time information stored in an internal time clock and updated in the external time-based clock. .

In particular, after a power failure, when powering up the electrical apparatus, a time information whose update has been maintained during the power failure by means of the internal time clock is displayed on an electrical appliance.

According to one embodiment of the invention, the time information of the internal time-based clock is updated at least one predetermined time by the time-based time information generated by the power supply network. .

The time-based internal time information can thus be updated and synchronized to the time information of the external time-based clock, such that the time drift of the internal time-based clock can be corrected.

Thus, when the electrical apparatus is turned on, the external time clock is updated by the information stored in the internal time clock.

This information of the clock based on internal time being kept up to date when the electrical device is powered by the time information of the external time clock, this time information remains synchronized from an electrical device to the other, so that when voltage of the electrical apparatus, each electrical apparatus displays and updates the external time-based clock from a common time information.

According to another preferred feature of the invention, the management method comprises a step of storing the time information of the clock based on time generated by the power supply network at least a predetermined time.

This memorization of the time of the external time-based clock makes it possible, after a cut-off of the supply of the apparatus and its resetting of the voltage, to have access to hourly information representative of a time at which the electrical apparatus was actually energized.

According to an advantageous characteristic of the invention, the management method comprises a step of calculating a duration of cut-off of the electrical supply of the apparatus, this cut-off time being obtained by the difference between the time information stored in an internal time-based clock obtained at the reading step and the time information memorized at the storing step.

It is thus possible to know the cut-off time of the power supply of an appliance, which is particularly advantageous for appliances of the refrigerator or freezer type for which the duration of a break in the power supply can call into question food preservation.

According to another embodiment of the invention, the time information of the internal time clock is set to zero at at least a predetermined time.

This reset of the clock based on internal time allows, at the time of powering the device, to obtain by displaying a time information substantially corresponding to the duration of the power failure of the device.

Preferably, this zeroing is performed when detecting a power off of the electrical device.

After powering on the electrical device, the time information read from the internal time clock, updated in the clock to External time base and displayed actually corresponds to the duration of the power failure of the device.

• une horloge à base de temps interne ;
• une horloge à base de temps générée par le réseau d'alimentation électrique dudit appareil ;
• des moyens d'affichage d'une information horaire de l'horloge à base de temps générée par le réseau d'alimentation électrique ;
• des moyens de détection d'une mise sous tension dudit appareil électrique ;
• des moyens de lecture d'une information horaire mémorisée dans l'horloge à base de temps interne ; et
• des moyens de mise à jour de l'horloge à base de temps générée par le réseau d'alimentation électrique, par l'information horaire mémorisée dans l'horloge à base de temps interne.

According to a second aspect of the invention, an electrical apparatus adapted to implement the display management method according to the invention comprises:

• a clock based on internal time;
• a time-based clock generated by the power supply network of said apparatus;
• means for displaying a time information of the clock based on time generated by the power supply network;
• means for detecting a power-up of said electrical apparatus;
• means for reading a time information stored in the internal time clock; and
• means for updating the time-based clock generated by the power supply network, by the time information stored in the internal time-based clock.

This electrical apparatus has characteristics and advantages similar to those of the method for managing a display of a time information that it is adapted to implement.

Other features and advantages of the invention will become apparent in the description below.

• la figure 1 est un schéma bloc illustrant un appareil électrique conforme à l'invention ;
• la figure 2A illustre un montage électrique d'une horloge à base de temps externe ;
• la figure 2B est une courbe illustrant la synchronisation d'une horloge à base de temps générée par le réseau d'alimentation électrique de l'appareil ;
• les figures 3A, 3B et 3C sont des algorithmes illustrant le procédé de gestion conforme à un mode de réalisation de l'invention ; et
• les figures 4A et 4B sont des algorithmes illustrant le procédé de gestion conforme à un autre mode de réalisation de l'invention.

In the accompanying drawings, given as non-limiting examples:

• the figure 1 is a block diagram illustrating an electrical apparatus according to the invention;
• the Figure 2A illustrates an electrical mounting of an external time clock;
• the Figure 2B is a curve illustrating the timing of a time-based clock generated by the power supply network of the apparatus;
• the FIGS. 3A, 3B and 3C are algorithms illustrating the management method according to an embodiment of the invention; and
• the Figures 4A and 4B are algorithms illustrating the management method according to another embodiment of the invention.

First of all, a suitable electrical apparatus will be described in implementing the display management method according to the invention.

This electrical apparatus is schematically illustrated in figure 1 .

Only the functional elements of this apparatus which allow the implementation of the management of the hourly information have been illustrated, all the elements and operating members specific to the electrical apparatus not being represented.

This electrical appliance may be in particular a domestic cooking oven or a microwave oven. It may also consist of a refrigerator or freezer.

It includes an internal time clock 10 and an external time clock 20 generated by the power supply network 30 of the apparatus 1.

The internal time-based clock 10 is a real time clock or Real Time Clock (RTC). This clock RTC 10 comprises one-hour incrementing means RTC 11, a quartz 12 and a backup power system 13.

This backup power supply 13 thus constitutes an autonomous power supply system for the clock RTC 10.

In the exemplary embodiment illustrated in figure 1 , this autonomous power system consists of a battery.

Of course, this battery 13 could be replaced by a capacitor associated with a diode for charging the capacitor by the power supply of the device when the latter is powered. The capacitor is then adapted to discharge when the electrical apparatus is de-energized to power the RTC clock. Such a system implementing a capacity capacitor equal for example to 47 mF has an autonomy greater than 48 hours. The stack 13 and the time incrementing means RTC 11 associated with the quartz 12 compose an autonomous time increment system with the quartz for time base.

The accuracy of such a clock RTC 10 is fixed by the quartz used, and in particular depends on the accuracy of quartz and its temperature behavior.

The external time-based clock 20 is a clock synchronized to the electrical network, and in particular by the zero crossing information of the mains voltage. This type of synchronization is commonly known as sector synchronization.

This external time-based clock 20 comprises a random access memory 21 (Ram or Ramdon Access Memory) adapted to store the time information, also hereinafter referred to as the time sector.

The increment of the time information of this external time clock is made at a microcontroller 22 adapted to analyze the value of the voltage V delivered by the power supply 30 of the electrical apparatus 1.

The Figure 2A illustrates for this purpose an electrical assembly for connecting the microcontroller 22 to the phase of the power supply 30 of the apparatus. In this embodiment, three resistors connected in series R have an impedance of 470 KΩ and the diodes D are of the type 1N41 48.

Of course, other methods for obtaining a synchronized signal on the power supply could be used, implementing for example a photo coupler, a transistor circuit or a peak signal detector.

In order to ignore the disturbances of the power supply, and in particular not to count down the unwanted zero voltage crossings, a timer associated with the microcontroller 22 is used.

We illustrated on the Figure 2B an example of obtaining this synchronization on the zero crossing of the voltage.

The upper part of the curve shows the voltage of the sector, and in particular the zero crossings of this voltage at the intersections of this curve with the line X.

The gray rectangles symbolize the duration of the timer which is slightly less than half a period of the voltage. During the duration of the timer, the zeroing of the voltage is ignored. Thus, although the input of the microcontroller detects multiple zero crossings of the voltage, some of these zero crossings are not taken into account as long as they occur during the timer, ie that is, in a predetermined period of time after each valid zero crossing of the voltage. For this, at each valid zero crossing of the voltage, the timer is reset.

At the input of the microcontroller 22, information is thus obtained which is synchronized with the mains voltage. By way of example, for a 50 Hz electrical network, by dividing this frequency by 100, a time base of frequency 1 Hz, that is to say a variation per second, is obtained.

The time information in memory 21 can thus be incremented from this time base of 1 Hz, the time information being thus incremented every second.

Display means 23 allow the display of a time information, including the display of the sector time in memory 21 synchronized to the power supply.

The electrical apparatus 1 also comprises storage means 24 constituted for example by a non-volatile memory (of the EEPROM type) which is adapted to store the time information of the time-based clock generated by the network. power supply.

In practice, this information is addressed by the microcontroller 22 from the sector time in memory 21.

In order to enable the implementation of the hourly management method of the invention, the microcontroller 22 is associated with software means including, in particular, means for reading the time information stored in the clock RTC 10. reset of the clock information of the clock RTC 10 and means for calculating a cut-off time of the power supply from the time information stored in the non-volatile memory 24 and the clock RTC 10.

In addition, the software means of the microcontroller 22 are adapted to detect the powering up of the electrical device as well as possibly de-energizing it.

This detection of voltage of the apparatus can be carried out on the basis of the zero crossing information of the voltage, the power off being detected a contrario when no zero crossing of the voltage is detected during a period of time. predetermined duration.

They also include means for reciprocal updating of the clock information of the RTC clock 10 and the time information of the external time clock 20.

Thus, the microcontroller 22 includes means for updating the time RTC in memory 11 by the sector hour in memory 21 and vice versa.

Of course, the schematic representation of the figure 1 is not limiting. In particular, the communication bus between the different elements may be different.

We will now describe with reference to FIGS. 3A to 3C a first embodiment of the method for managing a display of a time information according to the invention.

This method of managing a display of a time information can be implemented in an apparatus as described above by using an internal time-based clock and an external time-based clock. 20.

As illustrated in figure 3A when the apparatus is in normal operation, and after initialization of the RTC clock 10 and the external time clock 20, the time keeping of the external time clock is performed by means of the synchronization of the time on the frequency of the electrical network. As explained above with reference to Figure 2B , a timer is used at the microcontroller 22.

At each detection of a zero crossing of the value of the voltage, a test step E10 makes it possible to check whether the duration of the timer is complete. If not, the process terminates and the zeroing of the voltage is ignored. This is for example a zero crossing E as illustrated in Figure 2A which actually corresponds to a disturbance of the electrical signal.

Conversely, if the test step E10 indicates that the duration of the timer is indeed over, the timer is reset in a reset step E11.

An increment step E12 is adapted to increment by one unit a state change counter of the voltage.

A test step E13 makes it possible to check whether this state change counter has reached the value of 100.

If not, the process ends until a next detection of the zeroing of the voltage.

When the state change counter has reached the value 100 at the end of the test step E13, an incrementing step E14 of the sector time is implemented. In practice, the sector time is increased by the value of one second.

Of course, the threshold value equal to 100 depends on the frequency of the power supply network and is valid in the case of a power supply at the frequency of 50 Hz.

A reset step E15 of the state change counter is then implemented in order to reset this counter.

The set of steps E10 to E15 is then repeated each time the voltage is switched off, in order to maintain the synchronization of the sector time with the frequency of the electrical network.

In parallel with this synchronization, an update process is performed as illustrated in FIG. figure 3B .

In this embodiment, this update is performed at the time of detecting de-energizing of the electrical apparatus.

This mode of operation is made possible in the case where the electrical device has after power off a power reserve, of the order of 100 ms after power failure.

In such a case, after a detection step E20 of de-energizing the electrical apparatus, an update step E21 of the clock information RTC by the time information of the clock to external time base is implemented.

In practice, this update step E21 consists of a sector time write operation in memory 21 in the memory 11 of the RTC clock 10.

In this embodiment, a storage step E22 of the time information of the external time clock is also implemented.

This storage step E22 consists of a step of writing the sector time in memory 21 in the non-volatile memory 24. The time stored in this non-volatile memory 24 is called in the following description the time stored.

Although it has been described in this embodiment the update of the RTC time and the time stored in the non-volatile memory 24 when detecting a power off of the electrical device, these update steps could also be implemented periodically when the electrical device is undervoltage, for example every minute.

In this case, the power off detection system is no longer required.

Thus, the RTC time is regularly updated from the sector time, thus avoiding any drift of this time information, in particular due to a temperature drift of the quartz.

We will now describe with reference to the figure 3C implementing the method of managing the display of a time information when the electrical apparatus is energized.

In practice, a detection step E30 is adapted to detect the energization of the electrical apparatus.

This power can be achieved after an inadvertent power failure or when connecting the electrical device by a user.

When the power-up of the apparatus is detected, a reading step E31 is adapted to obtain the RTC time stored in the memory 11 of the clock RTC 10.

Thanks to the update method described above with reference to the figure 3B and the standalone power supply of the internal time-based clock 10, the RTC time corresponds to the real time.

A step E32 update of the time-based clock generated by the power supply network is implemented from the RTC time read at the reading step E31.

This update step E32 automatically resets the value of the clock synchronized to the frequency of the electrical network from the time stored in the RTC clock.

In practice, the value of the RTC time is copied to the memory 21 of the external time clock 20.

In this embodiment, a calculation step E33 makes it possible to calculate the cut-off time of the power supply of the apparatus. In practice, this cut-off time is obtained by the difference between the time information stored in the clock RTC, as obtained at the reading step E31, and the time information stored in the non-volatile memory 24 of the apparatus as stored in the storage step E22 described with reference to FIG. figure 3B .

A display control may optionally be actuated by the user to allow the temporary display at the display means 23 of the apparatus of this cut-off time thus calculated by the microcontroller E22.

Finally, a display step E34 informs the user of the updated sector time from the time information obtained in the reading step E31.

Thanks to this management method according to the invention, the hourly information managed by the clock synchronized to the frequency of the electrical network can be permanently correct after a single initialization of this time information at the time of commissioning. 'electrical appliance.

In addition, when several similar electrical appliances are used, the time information displayed by each of these devices remains synchronized over time.

In any case, the method may include an E35 test step for checking whether the user wishes to make an adjustment of the external time-based clock.

This test step E35 may consist in detecting the user's operation of a particular command accessible on a control panel of the apparatus.

If so, the sector time in memory 21 is updated in a step E36 from a new value introduced by the user.

In such a case, an updating step E37 is implemented in order to automatically update the RTC time in memory 11 from the modified sector time to the update step E36.

Similarly, an update step E38 of the time stored in the non-volatile memory 24 is implemented starting from the acquired sector time in the updating step E36.

The entire process is then reiterated when a new power-up E30 of the electrical device is detected.

Of course, in another embodiment of the invention, the non-volatile memory could be suppressed, when it is not useful to obtain the cut-off time of the power supply.

In such a case, the updating steps E22, E38 of the memorized time and the calculation step E23 of the cut-off time are omitted.

We will now describe with reference to Figures 4A and 4B another embodiment of the invention.

This embodiment of the invention also uses the time synchronization sector as described above with reference to the figure 3A .

When the device is under voltage, a detection step E40 of a power off of the device is implemented.

If so, the RTC time in memory 11 of the internal time clock is set to zero in a reset step E41.

Although this zeroing step E41 is preferably performed when detecting a power off of the electrical apparatus, it could also be performed periodically, when the electrical device is under-voltage, and in particular every minute. In this case, the means for detecting the power off of the device can be deleted.

The method of managing the hourly information at the level of the electrical apparatus comprises, as illustrated in FIG. Figure 4B , a detection step E50 of an undervoltage of the electrical apparatus.

As before, this powering up of the electrical device can be carried out after an inadvertent interruption of the power supply or following a connection of the electrical device to the mains.

A reading step E51 of a time information stored in the clock RTC is then implemented.

Since the RTC time has been reset periodically when the electrical device is under voltage, or at least when detecting a power off, as described above with reference to the Figure 4A , the RTC time in memory 11 obtained at this reading step E51 actually corresponds to the duration of the power failure.

A step E52 update of the sector time is performed from the time information obtained in the reading step E51.

A display step E53 of the sector time thus makes it possible to display the duration of the interruption of the power supply.

A test step E54 makes it possible to identify a possible setting of the time by the user as described previously with reference to step E35 of the figure 3C .

If so, an update step E55 of the sector hour in memory 21 is implemented.

This embodiment of the invention thus makes it possible to obtain the duration of the interruption of the power supply, without requiring the use of a non-volatile memory.

Knowledge of the duration of the power failure is particularly interesting for electrical appliances of the refrigerator or freezer type to detect a possible break in the refrigeration chain storage of food stored in this type of device.

Of course, many modifications can be made to the embodiments described above without departing from the scope of the invention as defined by the appended claims.

Claims (18)

1. Method of managing a display of time information in an electrical appliance (1) comprising an internal time-base clock (10) and a time-base clock (20) generated by the electrical supply system of the appliance, comprising the following steps:

   - detection (E30, E50) of a powering up of the electrical appliance;

   - reading (E31, E51) of time information stored in an internal time-base clock;

   - updating (E32, E52) of the time-base clock (20) generated by the electrical supply system by the time information stored in the internal time-base clock (10); and

   - display (E34, E53) of the said time information of the time-base clock (20) generated by the electrical supply system.
2. Management method according to claim 1, characterised in that the time information of the internal time-base clock (10) is updated at at least one predetermined moment by the time information of the time-base clock (20) generated by the electrical supply system.
3. Management method according to claim 2, characterised in that the said updating is carried out periodically when the electrical appliance is powered up.
4. Management method according to claim 2, characterised in that the said updating is carried out when it is detected (E20) that the electrical appliance is powered down.
5. Management method according to one of claims 1 to 4, characterised in that it also comprises a step (E22) of storing time information of the time-base clock generated by the electrical supply system at at least one predetermined moment.
6. Management method according to claim 5, characterised in that the said storage step (E22) is implemented periodically.
7. Management method according to claim 5, characterised in that the said storage step (E22) is implemented after detection (E20) that the electrical appliance is powered down.
8. Management method according to one of claims 5 to 7, characterised in that it also comprises a step (E33) of calculating a duration of cutoff of the electrical supply to the apparatus, the said duration of cutoff being obtained by the difference between the said time information stored in an internal time-base clock (E31) obtained at the reading step and the said time information stored at the said storage step (E22).
9. Management method according to claim 1, characterised in that the time information of the internal time-base clock (10) is zeroed at at least one predetermined moment.
10. Management method according to claim 9, characterised in that the said zeroing (E41) is carried out periodically when the electrical appliance is powered up.
11. Management method according to claim 9, characterised in that the said zeroing (E41) is carried out when a powering down of the electrical appliance is detected (E40).
12. Electrical appliance suitable for implementing the display management method according to one of claims 1 to 11, comprising:

    - an internal time-base clock (10);

    - a time-base clock (20) generated by the electrical supply system (30) of the said appliance (1);

    - means (23) of displaying time information of the time-base clock (20) generated by the electrical supply system (30);

    - means (22) of detecting a powering up of the said electrical appliance,

    - means (22) of reading time information stored in the internal time-base clock (10); and

    - means (22) of updating the time-base clock (20) generated by the electrical supply system, by the time information stored in the internal time-base clock (10).
13. Electrical appliance according to claim 12, characterised in that it also comprises means (22) of updating the time information of the internal time-base clock (10) by the time information of the time-base clock (20) generated by the electrical supply system (30).
14. Electrical appliance according to one of claims 12 or 13, characterised in that it comprises storage means (24) suitable for storing, at a predetermined moment, time information of the time-base clock (20) generated by the electrical supply system.
15. Electrical appliance according to claim 14, characterised in that it comprises means (22) of calculating a duration of cutoff of the electrical supply.
16. Electrical appliance according to claim 12, characterised in that it comprises means (22) of zeroing the time information of the internal time-base clock (10).
17. Electrical appliance according to one of claims 12 to 16, characterised in that the said internal time-base clock (10) is a real-time clock (11) associated with a crystal (12) and a self-contained electrical supply (13).
18. Electrical appliance according to one of claims 12 to 17, characterised in that the time-base clock (20) generated by the electrical supply system (30) of the appliance is a clock synchronised on the frequency of the electrical system.

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