ES2372659T3 - ELECTRONIC SECURITY SYSTEM FOR AN APPLIANCES WITH AN ACCESS DOOR. - Google Patents

Abstract

An electric household appliance (1) comprising a casing (2); a laundry drum (3) housed inside the casing (2) and facing an opening (4) formed in the casing (2); an access door (5) fitted to the casing (2) to move between an open position and a closed position opening and closing the opening (4) respectively; electronic switching means (35) which switch to off or on to respectively disconnect or connect the electric household appliance (1) to a power line (9); electric household appliance (1) comprising an electronic safety system (6)(30)(60) configured to detecting a hazard condition corresponding to said access door (5) being opened during a black out, or a safety condition corresponding to the access door (5) not being opened during the black out; and selectively disabling or enabling electronic switching means (35) upon detection of said hazard condition or said safety condition respectively.

Description

Electronic security system for an appliance with an access door

The present invention relates to an electronic security system for an appliance with an access door.

More specifically, the present invention relates to an electronic safety system for controlling the new start-up of an appliance, such as a washing machine and / or a dryer or any other similar appliance, following a blackout, to which the The following description refers purely by way of example.

As is known, some known appliances such as washing machines or dryers, comprise a piece of furniture; a drum for clothes housed in the furniture and in communication with the outside through an access opening to the drum in the furniture; and a door to open / close the opening.

Some of the aforementioned appliances are equipped with a safety system that mechanically connects the door with a safety switch by means of a main power supply circuit connected to the power supply line of the appliance.

When the door is opened, the safety switch is activated to interrupt the power and immediately stop the machine; and, conversely, when the door is closed again, the main circuit safety switch closes to power and restart the machine.

Safety systems of this class have the main drawback of automatically restarting the machine when the door is closed, when the safety switch is closed and, thus, supplying power to the machine.

As a result, although the safety switch of the main power supply circuit ensures that the machine stops immediately if the door is inadvertently opened during the wash cycle, it fails to face other dangerous situations.

During a power outage, for example, the door can be opened, allowing a child to enter the drum of the washing machine. In which case, the accidental closing of the door causes the safety switch to close, so that the machine can be restarted when the power is restored. That is, when the power is restored with the safety switch closed, the machine starts again automatically, with disastrous consequences for the child locked in the drum.

In appliances of the aforementioned type, there is therefore a need to determine a danger condition caused by the opening of the door during a blackout, in order to prevent the machine from automatically restarting when the power is restored and distinguishing between the aforementioned danger condition and a condition "not dangerous", in which the door has not been opened during a blackout, so that the machine can be safely restarted automatically.

US 5,276,284 discloses an disabling device for a power supply switch to put out of service a power switch intended to activate and deactivate electrical equipment contained within a housing. The power switch disqualifier includes a housing provided with an access opening and an associated access door. The access door is provided with a latch to secure the door in the closed position. A switch is provided to activate and deactivate at least one electrical component protected by the housing. A switch enabler for application with the deactivation lever is provided to selectively enable and disable the switch.

US 4,461,940 describes a safe device against failures for use in heating appliances including an electric oven and a microwave oven. More particularly, it refers to a fail safe device that includes an electronic control circuit for controlling a main circuit of the heating apparatus and a mechanical latch for unlocking actuation levers for safe breakers in response to the opening and closing movement. of a door and the closing of a main circuit breaker when a cooking start button is activated mechanically.

Document US 2003/197387 describes a door interlocking that has a function of a newly commissioned blocking function for an electrical appliance in order to, once the appliance door has been opened during operation thereof, prevent that the electrical appliance is automatically restarted when the appliance door is closed again. To this end, the door interlocking according to the invention comprises an interlocking device that, in a closed position, locks the door of an electrical appliance and that, in an open position, leaves the door free, and a locking device for the new setting. in operation which, in a free state, allows the operation of the electrical device and in a locked state prevents the operation of the electrical device.

US 4,056,891 describes a hitch circuit inserted between the door switch of a dryer or any other device that operates unattended and its operating components. Thus, when the door switch is opened, the circuit is disengaged and the subsequent closing of the door will not resume operation of the device. To make such a resumption of operation possible, a push-type switch is included to close through the hitch circuit, so that the closing sequence of the door switch, followed by manual pressing of the push-to-close type switch, will restart the device.

An object of the present invention is to provide an appliance characterized by an access door and an electronic control device designed as a safeguard against the aforementioned danger by preventing the machine from automatically restarting in the event that the door has been opened. Access during a blackout.

It is also an object of the present invention to provide an appliance characterized by an electronic safety system designed to restart the machine correctly and safely after a power failure.

According to the present invention, an appliance is provided as claimed in claim 1 and, preferably but not necessarily, in any one of the claims that, directly or indirectly, depend on claim 1.

In accordance with the present invention, there is also provided an electronic safety system that can be installed in an appliance as claimed in claim 15.

A non-limiting embodiment of the present invention will be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 shows a schematic front view of an appliance characterized by an electronic security system in accordance with the teachings of the present invention;

Figure 2 shows a schematic view of the electronic security system of Figure 1;

Figure 3 shows a schematic front view of a different embodiment of an appliance characterized by an electronic safety system according to the present invention;

Figure 4 shows a block diagram of the electronic safety system installed in the machine of Figure 3;

Figure 5 shows a process chart of the operations performed by the electronic security system of Figure 4;

Figure 6 shows a process chart of the checking operations carried out by the electronic security system of Figure 4;

Figure 7 shows a schematic view of a different embodiment of the electronic security system of Figure 4;

Figure 8 shows a process chart of the checking operations carried out by the electronic security system of Figure 7.

In Figure 1, the number 1 indicates together an appliance comprising substantially a piece of furniture 2; a drum 3 for the clothes mounted inside the furniture 2 to contain a given amount of clothes and directly faced with an opening 4 for loading / unloading the clothes, formed in the furniture 2; and an access door 5 mounted on the furniture 2 to move, for example to rotate, between an open position and a closed position, opening and closing, respectively, the opening 4.

The appliance 1 can be a washer and / or dryer machine or any similar machine and comprises an electronic safety system 6 to determine a danger condition - corresponding to the opening of door 5 when the power supply to the machine is interrupted , for example, during a power failure (blackout) - or a safety condition - corresponding to the fact that door 5 is not opened during the power failure.

The electronic safety system 6 is also designed to selectively disable or enable the operation of the machine 1 when the danger or safety condition is detected, respectively.

In the examples of Figures 1 and 2, the machine comprises various internal electrical equipment 7, such as an electric motor, pumps and various known electrical devices; and a main current circuit 8 that connects the internal electrical equipment 7 with a main power supply 9 comprising, for example, an electrical conduction line with a predetermined supply voltage V1 of, preferably but not necessarily, about 230 V.

The main current circuit 8 comprises a current branch 10 that connects the external electrical power supply to the electrical equipment 7; an electronic switch 11 located on the branch 10 and opening or closing to, respectively, disconnect or connect the machine 1 with the power supply 9; and an electromechanical switch 14 located on the current branch 10 and connected to the door 5 to open or close when the door 5 is moved to the open position and to the closed position, respectively.

More specifically, the electronic switch 11 may, preferably but not necessarily, comprise a TRIAC that receives a SCOM control signal and that, depending on the SCOM control signal, passes into conduction.

or out of conduction to, respectively, connect or disconnect the power supply to the electrical equipment 7.

The electronic safety system 6 comprises a detection module 12 for detecting the danger or safety condition; and a control module 13 to selectively disable or enable the electronic switch 11 when the danger or safety condition is detected, respectively.

With reference to Figure 2, the detection module 12 comprises an electrical detection branch 15 having a first terminal at a reference voltage V2 of, preferably but not necessarily, V2 = 5 V; and mobile electrical contact 16 located in the electric detection branch 15 and movable between a working position, in which the electric detection branch 15 closes to put a second terminal at a voltage V3 = V2, and a rest position in the one that opens the electrical detection branch 15 to set the second terminal to a voltage V3 = 0 V.

The detection module 12 also comprises a mechanism 18 that cooperates with the door 5 to move the electrical contact 16 mechanically from the working position to the rest position when the door 5 is moved from the closed position to the open position. More specifically, the mechanism 18 is designed not to move the electrical contact 16 in any way when the door 5 moves from the open position to the closed position.

The detection module 12 also comprises an electromagnetic device 19 which, when excited, generates a magnetic field to move the electrical contact 16 from the rest position, that is, from opening, to the working position, that is, of closing of the branch of electrical detection 15.

In the example shown, the electromagnetic device 19 may comprise a coil that receives an excitation signal SE to generate a magnetic field to move the electrical contact 16 from the resting position to the working position.

The electrical sensing branch 15 therefore generates in the second terminal a status signal ST indicating in code the danger condition, when the electrical contact 16 is in the rest position corresponding to a zero voltage V3, or the condition safety when the electrical contact 16 is in the working position corresponding to a voltage V3 = V2.

The control module 13 comprises a microprocessor having a first input connected to the second terminal of the electrical detection branch 15 to receive the status signal ST; a second input that receives a signal of enable priority, SA; a first output that supplies the SCOM control signal to the electronic switch 11; and a second output that supplies the excitation signal SE to the electromagnetic device 19.

In the example shown, when the ST signal indicates the danger condition, the control module 13 generates the SCOM control signal that disables the electronic switch 11; and, when the ST signal indicates the safety condition, the control module 13 generates the SCOM control signal to enable the electronic switch 11.

The signal SA to enable priority can be generated by a control interconnection 21 of the furniture 2, to allow the user to consent to start the machine 1 after a power failure. In the example of Fig. 2, the control interconnection 21 comprises a button that is pressed by the user to feed the SA signal to enable priority to the control module.

In the case of a power failure during a washing cycle of machine 1, the following situations may occur.

If the door 5 has been kept closed during the entire power outage, the electrical contact 16 is in the working position, so that the electric detection branch 15 generates the status signal ST indicating the safety condition. When the power is restored, the control module 13, which receives the ST status signal indicating the safety condition, therefore generates the SCOM control signal to enable the TRIAC and allow the machine to continue with the interrupted wash cycle by the power failure.

On the contrary, if the door 5 is opened during the power failure, the mechanism 18 moves the electrical contact 16 from the working position to the rest position. At this stage, the electromagnetic device 19, which receives no excitation signal from the control module, does not generate any magnetic field, whereby the electrical contact 16 remains in the rest position. The closing of the door 5 does not produce any movement of the electrical contact 16 which, therefore, is maintained in the rest position, thus generating a status signal ST indicative of the danger condition.

When the power is restored, the control module 13 adopts the danger condition indicated in the ST status signal and generates the SCOM control signal to keep the electronic switch 11 disabled and thus interrupt the power supply to the electrical equipment 7 In which case, the control module 13 keeps the TRIAC and, therefore, the machine 1, disabled and continues to wait for the priority enable signal SA from the user. The waiting condition ends when the user presses the button to generate the SA signal to enable priority. More specifically, upon receipt of the SA signal to enable priority, the control module 13 enables the TRIAC to allow the machine 1 to start operating again and, at the same time, feeds the excitation signal SE to the electromagnetic device 19, which move electrical contact 16 to the working position.

In accordance with the present invention, as shown in Figures 1 and 2 and in light of the above description, the electronic security system 6 is configured to: detect the danger condition corresponding to the fact that said access door has been open during a power outage, or a safety condition corresponding to the fact that said access door has not been opened during said power failure; and selectively disabling or enabling said electronic means of interruption upon detection of said danger condition or said safety condition, respectively.

In detail, the electronic security system 6 comprises detection means 12 comprising a movable electrical contact 16 between a working position and a resting position; mechanical means 18 cooperating with the access door 5 to move the electrical contact 16 from the working position to the rest position when the access door 5 is moved to the open position; and electromagnetic means 19 that generate a magnetic field to move the electrical contact 16 to the working position.

In detail, the electronic control means 13 are configured to disable the electronic interruption means 11 when the electrical contact 16 is in the rest position or to enable the electronic interruption means 11 when the electrical contact 16 is in the working position.

In more detail, the machine 1 comprises interconnection means 21 in the furniture 2 to allow a user to generate an SA signal to enable the priority that makes it possible for the appliance 1 to function. Upon receipt of the signal (SA) to enable priority, the electronic control means 13 changes to the electronic interruption means 11 from disconnection to connection.

Upon receiving said signal SA to enable priority, the electronic control means 13 send said electromagnetic means 19 to generate a magnetic field to move the contact 16 of said rest position to said working position.

More specifically, the mechanical means 18 are designed not to move the electrical contact 16 when the access door 5 is moved from the open position to the closed position.

In detail, the electronic interruption means 11 comprise a TRIAC; The electronic control means 13 comprise a microprocessor, while the electromagnetic means 19 comprise an electric coil.

The electronic security system 6 described above has the advantage of eliminating the danger imposed by the automatic start-up of the machine after a power failure during which the machine door has been opened.

Of course, changes can be made to the electronic control device described herein without, however, departing from the scope of the present invention as defined by the appended claims.

In detail, Figures 3 and 4 show a second embodiment of the present invention in which an electronic safety system 30 is configured to detect a dangerous condition caused by the opening of the door 5 during a blackout and to discriminate between it and a " safety condition ", in order to automatically restart the machine without user intervention.

In detail, the security system 30 is configured to determine the opening or closing of the door 5 during the time interval " t of the blackout; and determine a "danger condition" and, at the same time, bring the machine 1 to a waiting state for new start-up when it is determined that at least one opening of the door 5 has been made during the time interval "t of the blackout."

In addition and preferably, the electronic security system 30 is also configured to determine a "danger condition" and, at the same time, bring the machine 1 to a waiting state for new start-up if the following conditions are met: the opening of the door 5 has not been determined during the time interval " t of the blackout and, at the same time, the time interval "blackout" is greater than a predetermined safety time interval "1."

Finally, the electronic security system 30 is configured to determine a "safe condition" and restarting machine 1 automatically, that is, without user assistance, from the moment the power failure interrupted operation, when it is not determined that the door was opened during the interval of Blackout time.

Preferably, as an additional security measure, the electronic security system 30 is configured to determine a "safe condition" and restarting machine 1 automatically, that is, without user assistance, from the point where the blackout interrupted its operation, when the following conditions are met: it is not determined that any opening of the door during the time interval " t of the blackout and, at the same time, the determined time interval " t of the blackout is less than the predetermined safety time interval, " 1.

Figures 3 and 4 show an illustrative embodiment of the electronic safety system 30 which substantially comprises a capacitor 31; a circuit 32 connected to a conduction line 36 having a predetermined low voltage V2 of, preferably but not necessarily, 12 V; an electric capacitor discharge circuit 33; a door switch 34 that is moved by the door 5 between a closed position and an open position; and an electronic switch 35 for high voltage, which opens or closes to, respectively, disconnect or connect the internal electrical equipment 7 of the machine 1 with a high voltage current line 9 having a predetermined high voltage V1, preferably but not necessarily, about 230 V.

In detail, the circuit 32 comprises a switch 39 for low voltage that is movable, based on a command signal SP, between a working position in which the electrical circuit 32 closes to put a terminal at a voltage low V2, and a rest position in which the electrical circuit 32 opens to set the terminal to 0 V.

More specifically, the closing of the door 5 electromechanically activates the switch 34 of the door to bring it to the closed position and connect the current conduction line 36 to the capacitor 31. Consequently, the voltage VS of a capacitor perception terminal 37 31, reaches a first value, that is, a value corresponding to the supply voltage VS = V2.

On the contrary, the opening of the door 5 electromechanically activates the switch 34 of the door to bring it to the open position (shown in Figure 4). In which case, the door switch 34 connects the capacitor perception terminal 37 with the capacitor discharge electrical circuit 33, thus bringing the voltage VS of the capacitor perception terminal 37 to a value V3 <V2, it is that is, a value corresponding to a ground voltage value VS = V3 = 0 V.

The electronic safety system 30 also comprises a sensing device 38 that measures the voltage VS at the capacitor perception terminal 37 for difference, depending on the voltage VS, between a "danger condition"; caused by the opening of door 5 during the blackout, and a "safe condition".

In the embodiment of Figure 4, the switch 34 of the door comprises three terminals, of which the first terminal 40 is connected with circuit 32 to the voltage V2; a second terminal 41 which is connected to a node 42 connected, in turn, to the capacitor discharge electrical circuit 33 and to the capacitor perception terminal 37 by means of a low leakage device 43; and a third terminal 44 that is directly connected to the capacitor perception terminal 37.

In the example of Figure 4, the closing of the door 5 leads the switch 34 of the door to the closed position, in which the first terminal 40 is connected to the second terminal 41, thus connecting the perception terminal 37 with the conduction line 36 on the main circuit 32.

On the contrary, the opening of the door 5 leads the switch 34 of the door to the open position, in which the second terminal 41 is disconnected from the current line 36 and connected to the third terminal 44, thus connecting the perception terminal 37 directly with the capacitor discharge electrical circuit 33.

With respect to the electronic switch 35 for high voltage, it may preferably comprise a relay configured to disconnect the internal electrical equipment 7 of the machine 1 from the high voltage current line 9 when the opening of the door 5 leads to the switch 34 of the door to the open position.

In addition, when the door switch 34 is in the closed position, the electronic switch 35 connects or, on the contrary, keeps the internal electrical equipment 7 of the machine 1 disconnected with respect to the high voltage current line 9 , based on an SP control signal.

The capacitor 31 comprises the perception terminal 37 connected to the node 42 through the low leakage device 43; and a terminal 46 connected to the ground line 47.

The capacitor discharge electrical circuit 33 comprises a device 48 for sensing the state of the door having an input terminal connected to node 42, and an output terminal that feeds a measurement signal having an electrical value (voltage or intensity ) which is a function of the voltage at node 42.

The device 48 for perceiving the state of the door can comprise, for example, an electric circuit R-C (not shown) to discharge the electric charge accumulated by the capacitor 31; and an interconnection circuit (not shown) to generate the measurement signal as a function of the voltage at node 42.

The sensing device 38 comprises a capacitor charge sensing device 49 having an input terminal connected to the perception terminal 37 and an output terminal that feeds a logical measurement signal having a first logical value when the voltage in the terminal 37 of perception is equal to voltage V2, and a second logical value when the voltage in terminal 37 of perception is equal to voltage V3.

The sensing device 38 also comprises a treatment unit 50, for example a microprocessor, which has a terminal connected to the output terminal of the state-sensing device 48 of the door of the electric circuit 33 of the capacitor discharge to receive the measurement signal; a terminal connected to the output terminal of the capacitor load sensing device 49 to receive the logical measurement signal; and a control terminal that feeds the control signal SP to the high voltage switch 35 and the low voltage switch 39.

In the example of FIG. 4, the electronic safety system 30, preferably but not necessarily, also comprises a test circuit 51 that cooperates with the treatment unit 50 to determine any failure of the capacitor charge sensing device 49.

More specifically, in the example of Figure 4, the test circuit 51 is connected in parallel with the capacitor 31 and thus has a terminal connected to the capacitor perception terminal 37; a terminal connected to the ground line 47; and a terminal connected to the treatment unit 50.

The operations performed by the electronic safety system 30 will now be described, with reference to Figure 5 and starting from an initial condition in which the following is assumed: the low voltage switch 39 of the circuit 32 is closed; machine 1 is in operation and executing the predetermined stage of the operating cycle, for example, the centrifugation stage of a wash cycle; and door 5 is closed.

At this stage, the door switch 34 is closed; node 42 and perception terminal 37 are at a voltage equal to voltage V2 = 12 V; the capacitor 31 is fully charged and the high voltage switch 35 is closed.

In case of power failure (block 100), the treatment unit 50 opens the low voltage switch 39 (block 110). In this step, the low voltage switch 39 causes the high voltage switch 35 to open.

At this point, the electronic security system 30 operates in three modes, depending on whether the door 5 is open / closed and the duration of the time interval that the blackout lasts.

More specifically, a first mode of operation (block 120) is applicable when the door 5 is opened during the blackout; a second mode of operation (block 130) is applicable when door 5 has not been opened and the electric current is restored within a time interval "equal to or less than the interval" time 1 of predetermined safety time; and a third mode of operation (block 140) is applicable when door 5 has not been opened and the blackout ends within a time interval "greater than the interval" 1 of predetermined safety time.

More specifically, if it is opened during the blackout, the door 5 causes the door switch 34 to open (block 150), thus connecting the capacitor perception terminal 37 to the capacitor discharge electrical circuit 33.

Consequently, the capacitor discharge electrical circuit 33 discharges the capacitor 31 (block 160) whereby the voltage VS in the perception terminal 37 passes from the voltage VS = V2 to the voltage VS = V3 (block 170).

At the end of the blackout (block 180), the treatment unit 50 activates a check procedure to determine the charge of the condenser 31 and, thus, determine whether or not the door 5 was opened during the blackout.

In this step, the treatment unit 50 measures the voltage VS = V3 = 0 V at the sensing terminal 37 and, thus, determines by means of the capacitor charge sensing device 49, that the door 5 is in the open state.

Consequently, the treatment unit 50 determines a danger condition (block 190) and brings the machine 1 to a waiting state (block 210), in which the machine 1 is not restarted at the end of the blackout . In more detail, in this step the treatment unit 50 generates the command signal SP that keeps the low voltage switch 39 and the high voltage switch 35 open.

The standby state is interrupted by a user command signal SA (output YES of block 210). Upon receipt of the control signal SA, the treatment unit 50 generates the control signal SP to close the low voltage switch 39 and the high voltage switch 35, so that the machine 1 starts operating again from the operational stage, for example the centrifugation stage, interrupted by the blackout (block 220).

In other words, if it is determined, as described above, the existence of a danger condition, the treatment unit 50, before closing switches 35 and 39 and activating the operating cycle, waits for a SA control signal generated by the user pressing a button 31 on machine 1.

The second mode of operation (block 130) is applicable when the blackout ends within a time interval equal to or less than the safety interval "1" and when door 5 has not been opened.

In this case, the door switch 34 remains closed (block 240) and the perception terminal 37 is still connected to the node 42 through the low leakage device 43.

The capacitor 31 is discharged by the capacitor discharge circuit 33 through the low leakage device 43, the discharge being delayed in a controlled manner by the low leakage device 43 (block 250).

It should be noted that the interval "security time 1" is calculated such that the voltage VS in the perception terminal 37 is substantially maintained at a voltage V2 during the entire security time interval 1 (block 260) .

When the electric current is restored (block 270), the treatment unit 50 that detects a voltage substantially equal to V2 at the perception terminal 37, therefore determines that the door 5 has not been opened and, at the same time, that the Blackout duration is shorter, "t9" 1 (block 280) and thus determines a safe condition (block 290).

Preferably, the electronic safety system 30 may comprise at least one test circuit 51 for determining the failure of said capacitor charge sensing device 49; said electronic safety system 30 being configured to bring the appliance 1 to a waiting state for new start-up when said test circuit 51 determines a failure of said capacitor charge device 49.

In this regard, the treatment unit 50 may be configured to implement, through the test circuit 51, a test procedure for determining the failure of the capacitor charge sensing device 33 (block 300).

Upon detection of a failure of the capacitor charge sensing device 33 (NO output of block 300), the treatment unit 50 brings the machine 1 to a waiting state (block 210), in which the machine 1 is not set running again at the end of the blackout.

The standby state is interrupted by a user command signal SA (output YES of block 210). When the control signal SA is received, the treatment unit 50 closes the switches 35 and 39 by means of the control signal SP, so that the machine 1 is restarted from the operational stage, for example the centrifugation stage, interrupted by the blackout (block 220).

On the contrary, when no fault of the capacitor sensing device 33 is detected and without waiting for a user command signal (block 310), the treatment unit 50 automatically closes the high voltage switch 35 and the switch 39 low voltage so that the cycle is restarted from the stage interrupted by the blackout.

Finally, the third mode of operation (block 140) is applicable in the case of a blackout that lasts longer than the safety time interval "and" 1 and that door 5 has not been opened.

In which case, the door switch 34 remains closed (block 320), the perception terminal 37 is still connected to the node 42 through the low leakage device 43. At this time, the high voltage switch 35 opens.

The low leakage device 43, therefore, gradually discharges the capacitor 31 to cause the voltage VS at the perception terminal 37 to adopt the ground voltage VS = V3 = 0 (block 330).

At the end of the blackout (block 350), the treatment unit 50 therefore determines a substantially low voltage VS = V3 at the perception terminal 37 and, therefore, the existence of a hazard condition (block 370).

When a danger condition is detected, the treatment unit 50 puts the machine 1 in a waiting state, pending the user's command signal SA (block 390). In detail, the treatment unit 50 generates the control signal SP, which keeps the high voltage switch 35 open.

Upon receipt of the control signal SA (output YES from block 390), the treatment unit 50 generates the control signal SP that closes the high voltage switch 35 so that the machine 1 starts again from the stage interrupted by the blackout (block 400).

Figure 6 shows a process chart of the operations of the check procedure performed by the electronic safety system 30 to determine a failure of the capacitor charge sensing device 33.

In this case, it is assumed that the test circuit 51 substantially comprises an electronic switch, for example a transistor, which can be controlled by the treatment unit 50 to discharge, at will, the capacitor 31.

The treatment unit 50 opens the electronic switch and closes the low voltage switch 39 (block 500) to charge the capacitor 31 (block 510) and, once the capacitor 31 is charged, it determines, by means of the sensor-sensing device 49 capacitor charge (block 520) if the voltage VS at the perception terminal 37 is equal to the voltage V2 (block 530).

If it is not, (NO output of block 530), the treatment unit 50 determines a failure of the capacitor charge sensing device 49 (block 540) and the procedure is terminated; otherwise (output YES from block 530), the treatment unit 50 opens the low voltage switch 39 and closes the high voltage switch 35, which completely discharges the capacitor 31 (block 550).

At this point, the treatment unit 50 determines, by means of the capacitor charge sensing device 49, if the voltage VS at the perception terminal 37 is equal to the voltage V3 (block 560). If it is not (NO output of block 560), the treatment unit 50 determines a failure of the capacitor charge sensing device 49 (block 540); otherwise (output YES of block 560), the correct operation of the capacitor charge sensing device 49 (block 570) is determined.

The electronic security system described has the main advantage, on the one hand, of guaranteeing a high degree of safety in the event of a blackout and, on the other hand, of being automatically activated when dangerous conditions are not detected at the end of the blackout.

The embodiment of Figure 7 refers to an electronic security system 60, similar to the electronic security system 30, and whose component parts are indicated, when possible, using the same reference numbers as for the corresponding parts of the system 60.

The electronic safety system 60 differs from the electronic safety system 30 in that the test circuit 51 is located between the terminal 46 of the capacitor 31 and the ground line 47, and in that it has a control terminal connected to the treatment unit 50.

More specifically, test circuit 51 is configured to set the voltage at terminal 46, upon receipt of an order, at a first reference value VZ = V3 = 0 V or a second reference value VZ = V4 = -12 V .

Referring to Figure 8, the treatment unit 50 of the electronic safety system 60 instructs the test circuit 51 to set the voltage VZ to the first reference value VZ = V3 = 0 V and, at the same time, close the switch 39 Low voltage (block 600) to charge capacitor 31 (block 610). Once the capacitor 31 is charged, the treatment unit 50 determines, by means of the capacitor charge sensing device 49, if the voltage VS at the perception terminal 37 (block 620) is equal to the voltage V2 (block 630).

If it is not (NO output of block 630), the treatment unit 50 determines a failure of the capacitor charge sensing device 49 (block 640) and the procedure is terminated; if it is (output YES of block 630) the treatment unit 50 opens the low voltage switch 39 and activates the test circuit 51, which sets the voltage in terminal 46 to the second reference value VZ = V4 = -12 V (block 650).

At this point, the treatment unit 50 determines, by means of the capacitor charge sensing device 49, if the voltage VS at the sensing terminal 11 is equal to the voltage V3 (block 660).

If it is not (NO output of block 660), the treatment unit determines a failure of the capacitor charge sensing device 49; if it is (output YES of block 660), the correct operation of the capacitor charge sensing device 49 (block 670) is determined.

Claims (15)

1. An appliance (1) comprising a piece of furniture (2); a drum (3) for clothes housed in the furniture (2) and facing an opening (4) formed in said furniture (2); an access door (5) mounted on the furniture (2) to move between an open position and a closed position, opening and closing, respectively, said opening (4); electronic interruption means (35) that open or close to, respectively, disconnect or connect the appliance (1) to a power line (9); said appliance being characterized (1) because it comprises an electronic safety system (6) (30) (60) configured to:

-

detecting a danger condition corresponding to said access door (5) being opened during a blackout, or a safety condition corresponding to said access door (5) not being opened during said blackout; and

-

selectively disable or enable said electronic interruption means (35) upon detection, respectively, of said danger condition or said safety condition.

2. An appliance as claimed in claim 1, wherein said electronic security system (30) is configured to determine the opening or closing of said door (5) during the time interval (&t; t) of a blackout; said electronic safety system (30) (60) being configured to, at the end of the blackout, automatically restart said appliance (1) from the operating stage interrupted by the blackout, when it is determined that said door ( 5) has not been opened during said blackout. 3. An appliance as claimed in claim 1 or claim 2, wherein said electronic security system (30) is configured to determine the opening or closing of said door (5) during the time interval (&quot; t) of a blackout; said electronic safety system (30) (60) being configured to, at the end of the blackout, automatically restart said appliance (1) from the operating stage interrupted by the blackout, when the following conditions exist:

-

it is determined that said door (5) has not been opened during said blackout and, at the same time,

-

The time interval ("t" of the blackout is substantially less than a predetermined safety time interval ("1").

Four.

 An appliance as claimed in claim 2, wherein said electronic safety system (30) (60) is configured to bring the appliance (1) to a waiting state for new start-up when at least one is determined an opening of the door during said blackout.

5.

 An appliance as claimed in claim 3, wherein said electronic safety system (30) (60) is configured to bring the appliance (1) to a waiting state for new start-up when it is determined that, during time interval (&t; t) of the blackout, said door (5) has not been opened and, at the same time, that the time interval (&t; t) of the blackout is greater than said time interval (&quot; 1) Default security.

6.

 An appliance as claimed in any one of the preceding claims, wherein said electronic safety system (30) (60) comprises: at least one capacitor (31) and an electric circuit (33) of capacitor discharge, configured to discharge said capacitor (31) if the door has been opened during said time interval (&t; t) of the blackout.

7.

 An appliance as claimed in claim 6, wherein said electronic security system (30) (60) comprises: door switch means (34) that switch between a first switch position in which they connect a first terminal ( 37) of said capacitor (31) with a current conduction line (36), so that the capacitor (31) is charged and the voltage at the first terminal (37) reaches a predetermined first value (V2), and a second position of the switch in which said first terminal (37) of said capacitor (31) is connected to said electric circuit (33) of discharge of the capacitor, in order to discharge the capacitor (31) and set the voltage in the first terminal (37) at a second predetermined value (V3);

said door (5) being designed so that when opening / closing it, it causes said door switch means (33) to switch between said first and said second positions; and said electronic security system (30) (60) also comprises sensing means (49, 50) for determining the opening of said door (5) as a function of the first (V2) or the second (V3) measured voltage values in the first terminal (37) of said capacitor (31).

8.

 An appliance as claimed in claim 7, and comprising a main switch (39) interposed between said door switch means (34) and said current conduction line (36);

said electronic safety system (30) (60) being configured to open said main switch (39) when the blackout occurs, and comprising means (43) with low leaks, connected to said first terminal (37) of said capacitor ( 31) and designed to discharge in time said capacitor (31) when said main switch (39) is opened and said door (5) remains closed during said time interval (&t; t) that the blackout lasts.

9.

 An appliance as claimed in claim 8, wherein said main switch (39) is a low voltage switch and said current conduction line (36) has a low voltage of about 12 V.

10.

 An appliance as claimed in claims 7, 8 and 9, wherein said sensing means

(38) comprise a treatment unit (50); and a capacitor load sensing device (49) connected to said first terminal (37) to measure the voltage (VS) in said first terminal (37), and configured to power said treatment unit (50) with a signal of measurement having a first value or a second value when the voltage (VS) measured in said first terminal (37) has said first value (V2) or said second voltage value (V3), respectively.

eleven.

 An appliance as claimed in claim 10, wherein said capacitor discharge electrical circuit (33) is connected to said treatment unit (50) for supplying it with a measurement signal, the voltage of which is related to the opening / the closing of said door (5).

12.

 An appliance as claimed in claim 1, wherein said sensing means (12) comprises a movable electrical contact (16) between a working position and a resting position; mechanical means (18) cooperating with said access door (5) to move said electrical contact (16) from said working position to said resting position when the access door (5) is moved to said open position; and electromagnetic means (19) that generate a magnetic field to move said electrical contact (16) to said working position.

13.

 An appliance as claimed in claim 12, wherein said electronic control means

(13) disable said electronic interruption means (11) when said electrical contact (16) is in said resting position or enable said electronic interruption means (11) when said electrical contact (16) is in said working position .

14.

 An appliance as claimed in claim 13, and comprising interconnecting means (21) for allowing a user to generate a signal (SA) for priority enabling means allowing operation of said appliance; when said priority enable signal (SA) is received, said electronic control means (13) change said electronic interruption means (11) from open to closed, preferably upon receiving said priority enable signal (SA), said electronic control means (13) send said electromagnetic means (19) to generate a magnetic field to move said electrical contact (16) from said rest position to said working position.

fifteen.

 An appliance as claimed in any one of claims 12 to 14, wherein the mechanical means (18) are designed not to move said electrical contact (16) when said access door (5) is moved from said open position to said closed position.