CLIAMS:We Claim;
1. A domestic refrigerator, comprising a thermally insulated housing (2), a storage compartment (3) intended for storing food and/or beverages and contained within the housing (2), a door leaf (11) for closing and opening the storage compartment (3), a temperature sensor (22) thermally coupled to the storage compartment (3) and intended for measuring the actual temperature of the storage compartment (3), a cooling device configured to cool the storage compartment (3), an electronic control device (6) configured to control the cooling device in response to the measured actual temperature obtained by the temperature sensor (22), an illumination device (23) configured to illuminate the storage compartment (3) only while the door leaf (11) is open, and a sensing device (26) configured to sense if the door leaf (11) is open or closed, characterized by a printed circuit board (27, 77) which is populated with the illumination device (23), the temperature sensor (22) and the sensing device (26).

2. The domestic refrigerator of claim 1, characterized in that the printed circuit board (27) has a length (l) and a width (w), wherein the width (w’) of the printed circuit board (27) around the temperature sensor (22) is less than the width (w) of the remaining printed circuit board (27).

3. The domestic refrigerator of claim 1 or 2, characterized in that the electronic control device (6) is attached to the housing (2) or the door leaf (11) remotely from the printed circuit board (27, 77), the printed circuit board (27, 77) and the electronic control device (6) being connected by means of electric wiring (31, 72) and the printed circuit board (27, 77) being supplied with electric energy via the electric wiring (31, 72).

4. The domestic refrigerator of claims 1, characterized in that the housing (2) comprises two side walls and a ceiling wall which comprise surfaces facing towards the storage compartment (3), the printed circuit board (27, 77) populated with the illumination device (23), the temperature sensor (22) and the sensing device (26) being attached into a recess (50) on the surface of one of the side walls or the ceiling wall, wherein the recess (50) is closed by a cover (54)

5. The domestic refrigerator of claim 1, characterized by a controllable switch (30) connected in series with the illumination device (23), said controllable switch is controlled by means of the sensing device (26) such that the controllable switch (30) is open while the door leaf (11) is closed preventing an electric current to flow through the illumination device (23), and the controllable switch is closed while the door leaf (11) is open, allowing an electric current to flow through the illumination device (23) in order to illuminate the storage compartment (3).

6. The domestic refrigerator of claim 1 or 5, characterized in that
- the illumination device (23) comprises a first terminal (A) connected at least indirectly to an electric voltage source (10), and a second terminal (C) connected at least indirectly to a first terminal (K) of the controllable switch (30), a second terminal (E) of the controllable switch (30) being connected at least indirectly to a node (29c) of the printed circuit board (27), or
- the controllable switch (30) comprises a first terminal connected at least indirectly to an electric voltage source (10), and a second terminal (C) connected at least indirectly to a first terminal of the illumination device (23), a second terminal of the illumination (23) being connected at least indirectly to a node (29c) of the printed circuit board (27).

7. The domestic refrigerator of claim 6, characterized in that the node (29c) is at least indirectly connected to the electronic control device (6), enabling the electronic control device (6) to evaluate the electric voltage at the node (29c), in particular in order to obtain information if the door leaf (11) is open or closed.

8. The domestic refrigerator of claim 7, characterized in that the electronic device (6) is configured, in response to the evaluated voltage at the node (29c), to activate at discrete time steps the temperature sensor (22) in order to measure the actual temperature of the storage compartment (3).

9. The domestic refrigerator of claim 1, characterized in that the temperature sensor comprises a first terminal (t1) and a second terminal (t2), the first terminal (t1) of the temperature sensor (22) being connected at least indirectly to the node (29c) of the printed circuit board (27).

10. The domestic refrigerator of claim 9, characterized in that the electronic control device (6) is configured to apply an electric voltage to the node (29c) in order to activate the temperature sensor (22) and, in order to measure the actual temperature of the storage compartment (3) by means of the temperature sensor (22), to evaluate the electric current flowing through the temperature sensor (22) and/or to evaluate the actual resistance of the temperature sensor (22).
,TagSPECI:The following specification particularly describes the invention and the manner in which it is to be performed.

Field of the invention
[001] The invention relates to a domestic refrigerator.

Background of the invention
[002] Conventional domestic refrigerators usually comprise a thermally insulated housing, a storage compartment intended for storing food and/or beverages and contained within the housing, a door leaf for closing and opening the storage compartment, a temperature sensor thermally coupled to the storage compartment and intended for measuring the actual temperature of the storage compartment, a cooling device configured to cool the storage compartment, an electronic control device configured to control the cooling device in response to the measured actual temperature obtained by the temperature sensor, an illumination device configured to illuminate the storage compartment only while the door leaf is open, and a sensing device configured to sense if the door leaf is open or closed.

[003] Published international application for patent No. 2013/125186 A1 discloses a refrigerator which comprises a main refrigerator body, a heat-insulated storage compartment, a compartment illumination device for illuminating the storage compartment, and a temperature sensor for sensing the temperature in the vicinity of the compartment illumination device. The compartment illumination device and the temperature sensor are installed in the inner box of the refrigerator and configured on the same substrate.

[004] The object of the invention is to provide a domestic refrigerator which comprises an illumination device for illuminating the storage compartment while the door leaf is open and a temperature sensor.

[005] The object of the invention is achieved by means of a domestic refrigerator, comprising a thermally insulated housing, a storage compartment intended for storing food and/or beverages and contained within the housing, a door leaf for closing and opening the storage compartment, a temperature sensor thermally coupled to the storage compartment and intended for measuring the actual temperature of the storage compartment, a cooling device configured to cool the storage compartment, an electronic control device configured to control the cooling device in response to the measured actual temperature obtained by the temperature sensor, an illumination device configured to illuminate the storage compartment only while the door leaf is open, a sensing device configured to sense if the door leaf is open or closed, and a printed circuit board which is populated with the illumination device, the temperature sensor and the sensing device.

[006] One disadvantage of conventional domestic refrigerators may be wiring harness routing and assembly as well as relative high part costs. According to the domestic refrigerator of this disclosure, the appliance illumination device, the temperature sensor and the sensing device are included into a single printed circuit board and/or housing. Additionally, further sensors, for instance, a humidity sensor can be mounted to this printed circuit board. The humidity sensor can be a separate sensor or combined with the temperature sensor in one chip.

[007] The domestic refrigerator in accordance with this disclosure can make it possible to reduce the pin count for a smart connection with the electronic control electronics, i.e. to reduce the number of electric contacts.

[008] In order to reduce the pin count, a bus connection may be included. For instance, an onboard controller may drive the illumination device and read the sensors. The data may be transferred from and to the control electronics of the appliance over the bus connection. The combination of the sensors can be designed fully flexible and scalable. Only the sensors needed for the selected appliance must be placed on the board. This gives the advantage of production with high numbers and therefore cost reduction.

[009] In one embodiment, the illumination device, the sensing device and the temperature sensor are combined and added to the single printed circuit board. Voltage supply and ground might be shared between these components. This ultimately reduce the pin counts by two and as well as wiring may be reduced by two. 5 pin or 6 pin connecters can be used. The temperature sensor may be thermally isolated from the sensing device and the illumination device. Also the temperature sensor may exposed to the cooling area, i.e. is thermally coupled to the storage compartment. The mechanical and printed circuit board design will be taken care in order to avoid heat from the illumination device to be transferred to the temperature sensor.

[0010] The inventive domestic refrigerator comprises the thermally insulated housing, which particularly comprises a rear wall and two side walls. In the housing, the storage compartment is contained. The storage compartment is intended for storing food and/or beverages. The storage compartment may preferably be intended to store the food and/or beverages at non-freezing temperatures greater than 0°C. The storage compartment may, however, also be intended to store food and/or beverages at temperatures less than 0°C.

[0011] Additionally, the domestic refrigerator comprises the door leaf which is preferably thermally insulating. The door leaf may be hinged relative to the housing by hinges. While the door leaf is open, the storage compartment can be accessed.

[0012] The domestic refrigerator comprises the cooling device which is configured to cool the storage compartment. The cooling device comprises preferably a refrigerant circuit as it is well known in the art. The cooling device may also comprise at least one fan as it is also known in the art.

[0013] The domestic refrigerator comprises the electronic control device which controls, preferably feedback controls the cooling device in response to the actual temperature of the storage compartment such that the storage compartment has at least an actual temperature equal a set temperature. The actual temperature is measured by means of the temperature sensor which is thermally coupled to the storage compartment.

[0014] Appropriate temperature sensors per se are known in the art. An appropriate temperature sensor may comprise a temperature dependent resistance. Then it is possible to evaluate the resistance of the temperature sensor in order to estimate or measure the actual temperature of the storage compartment. To estimate or measure the resistance of the temperature sensor, an electric voltage can be applied to the temperature sensor and then the electric current flowing through the temperature sensor may be measured.

[0015] The domestic refrigerator also comprises the illumination device which is intended to illuminate the storage compartment while the door leaf is open. The illumination device comprises at least one light emitting diode or is at least one light emitting diode.

[0016] The illumination device shall only illuminate the storage compartment while the door leaf is open. When the door leaf is closed, the illumination device shall be switched off. In order to obtain information if the door leaf is open or closed, the domestic refrigerator comprises the sensing device. Sensing devices per se are also known in the art. The sensing device is preferably a contactless sensing device. An appropriate example of such a sensing device is a magnetic field sensor, for instance, a hall sensor or a magnetic resistance sensor whose output signal depends on the strength of a magnetic field. Then, the door leaf may comprise a magnet whose magnetic field is coupled to the magnetic field sensor while the door leaf is closed and de-coupled while the door leaf is open.

[0017] The output signal of the sensing device is indicative if the door leaf is open or closed.
[0018] According to the domestic refrigerator of this disclosure, the illumination device, the sensing device and the temperature sensor are all placed on one printed circuit board. Because of this construction it is possible to have relative compact and small electronic components, potentially resulting in faster and thus more cost effective assembling the inventive domestic refrigerator. Additional devices or sensors, in particular a humidity sensor, may also be attached to the printed circuit board.

[0019] The populated printed circuit board may be placed within a separate housing.

[0020] The temperature sensor may be at least partly thermally decoupled from the printed circuit board in order to at least reduce a negative effect of a heated printed circuit board caused, for instance, by the illumination device.

[0021] The printed circuit board may have a length and a width. In accordance with one embodiment of the printed circuit board, the width of the printed circuit board around the temperature sensor is less than the width of the remaining printed circuit board. Then, a heated printed circuit board may less affect the temperature sensor, improving a more accurate measurement of the actual temperature of the storage compartment.

[0022] The electronic control device may be attached to the housing or to the door leaf remotely from the printed circuit board. In particular, the printed circuit board and the electronic control device may be connected by means of electric wiring and preferably the printed circuit board may be supplied with electric energy via the electric wiring. The electronic control device may, for instance, be placed within a machinery compartment of the domestic refrigerator.

[0023] The housing of the domestic refrigerator may comprise two side walls and a ceiling wall which comprise surfaces facing towards the storage compartment. The printed circuit board populated with the illumination device, the temperature sensor and the sensing device may preferably be attached into a recess on the surface of one of the side walls or the ceiling wall. This may be realized by deep-drawing the recess into the surface or a liner of the relevant side wall or the ceiling wall. It is also possible that a separate device is fastened into an aperture of the relevant surface, wherein this device includes the recess. This device is may be made from plastics and/or is a one-piece device. The recess may be closed by a cover. The cover is may be made from plastics and/or is fastened to the device by means of snaps. The recess including the cover may constitute an housing for the populated printed circuit board.

[0024] The domestic refrigerator may comprise a controllable switch connected in series with the illumination device. The controllable switch is also mounted to the printed circuit board. The controllable switch is controlled by means of the sensing device, by means of the output signal of the sensing device. The controllable switch is a controllable semiconductor switch. This controllable switch may, for instance, be a transistor, for instance, a bipolar transistor.

[0025] The controllable switch is controlled by means of the sensing device such that the controllable switch is open while the door leaf is closed. This prevents an electric current to flow through the illumination device. Consequently, the illumination device is switched off while the door leaf is closed. While the door leaf is open, the sensing device controls the switch such that it is closed, allowing an electric current to flow through the illumination device in order to illuminate the storage compartment.

[0026] The illumination device may comprise a first terminal and a second terminal, and the controllable switch may comprise a first terminal and a second terminal.

[0027] The first terminal of the illumination device may be connected at least indirectly, preferably directly, to an electric voltage source. The electric voltage of the voltage source may be provided via the wiring to the printed circuit board. Then, the second terminal of the illumination device may be at least indirectly, preferably directly connected to the first terminal of the controllable switch. The second terminal of the controllable switch may then be connected at least indirectly to a node of the printed circuit board. Alternatively, the first terminal of the controllable switch may be connected at least indirectly to the electric voltage source and the second terminal of the controllable switch may be connected at least indirectly to the first terminal of the illumination device. The second terminal of the illumination device may then be connected at least indirectly to the node of the printed circuit board. This node is in particular at least indirectly connected via the wiring to the electronic control device, enabling the electronic control device to evaluate the electric voltage at the node. The node may be an electric contact of the printed circuit board. While the door leaf is open, the sensing device causes the controllable switch to be closed. Then, the voltage source is connected to the node via the closed controllable switch and the illumination device. Then, a significant voltage is present at the node. While the door leaf is closed, the controllable switch is open and no voltage is present at the node. As a result, the voltage present at the node is indicative of the state of the door leaf, enabling the electronic control device to obtain information if the door leaf is open or closed by evaluating the voltage present at the node.

[0028] The domestic refrigerator may be designed not to continuously measure the actual temperature of the storage compartment by means of the temperature sensor. In particular, the electronic control device may be configured, in response to the evaluated voltage at the node, to activate at discrete time steps the temperature sensor in order to measure the actual temperature of the storage compartment.

[0029] The temperature sensor may also comprise a first terminal and a second terminal.

[0030] The printed circuit board may be connected to the electronic printed circuit board by means of the wirings. Then, the printed circuit board may comprise electric contacts. In order to reduce the number of electric contacts of the printed circuit board, the first terminal of the temperature sensor may be connected at least indirectly to the node of the printed circuit board. According to this embodiment, the printed circuit board may only need three electric contacts: A first electric contact for supplying the printed circuit board with the electric voltage of the voltage source. This voltage is necessary to power the illumination device and/or the sensing device. A second electric contact to connect, for instance, the second terminal of the temperature sensor and may be a contact of the sensing device to ground, and a third electric contact connected to the node. For this embodiment, the electronic control device of the inventive domestic refrigerator may be configured to apply an electric voltage to the node in order to activate the temperature sensor and, in order to measure the actual temperature of the storage compartment by means of the temperature sensor, to evaluate the electric current flowing through the temperature sensor and/or to evaluate the actual resistance of the temperature sensor.

[0031] According to another embodiment, a reduction of the pin count from the 5/6 pin circuit is possible by smart connection within the printed circuit board, pin mapping in control electronics and modification in a software of the electronic control device. Three pins, i.e. electric contacts of the printed circuit board may be configured for supply voltage, ground and only one output for the components of printed circuit board. The voltage for the temperature sensor may be +5V. This may be only available when the electronic control device reads the temperature value. When the door leaf is open, the sensing device may drive a transistor which is used as the controllable switch. Due to this, the electronic control device, for instance an analog digital converter of the electronic control device will read a relatively high voltage of, for instance, nearly 4V at the node. With this high voltage, the electronic control device can identify if the door is open. Then, the electronic control device may connect a driver circuit to the node and drives with the transistor the illumination device. The electronic control device will read a relative small voltage drop at the driving circuit to identify if the door leaf is open. If the door leaf is closed, then the transistor will not be driven. The output is disconnected from the sensing device and the illumination device. The output voltage will be nearly zero. The electronic control device can read the temperature sensor value by turning on the voltage for the temperature sensor.

Brief Description of the accompanying drawings
[0032] The invention will be described in greater detail hereafter, by way of non-limiting examples, with reference to the embodiments shown in the drawings, wherein
[0033] Fig. 1 is a perspective view of a domestic refrigerator;
[0034] Fig. 2 is a circuit diagram of an electronic circuit;
[0035] Fig. 3 is the electronic circuit depicted in Fig. 2 comprising a printed circuit board and electronic devices;
[0036] Fig. 4 is a top view of several printed circuit boards;
[0037] Fig. 5 is an exploded view drawing of a part of the domestic refrigerator;
[0038] Fig. 6 is a circuit diagram of an alternative electronic circuit;
[0039] Fig. 7 is a further electronic circuit comprising a printed circuit board and electronic devices; and
[0040] Fig. 8 is a circuit diagram of the electronic circuit depicted in Fig. 7.

Detailed description of the embodiments
[0041] FIG.1 shows a perspective view of a domestic refrigerator 1. The refrigerator 1 comprises a refrigerator cabinet or housing 2 which is thermally insulated. Disposed within the cabinet 2 is a fresh food compartment 3 and a freezer compartment 4 located above the fresh food compartment 3.

[0042] The housing 2 comprises thermally insulated walls for the freezing compartment 4 and the fresh food compartment 3. In particular, the housing 2 comprising a rear wall, side walls, a bottom wall and a ceiling wall and a thermally insolated divisional wall 5 separating the fresh food compartment 3 from the freezer compartment 4. The housing 2 was manufactured utilizing a foaming process as it is generally known in the art.

[0043] The domestic refrigerator 1 further comprises a refrigerant circuit for cooling the fresh food compartment 3 and the freezer compartment 4. In particular, the refrigerant circuit comprises, as it is generally known in the art, at least one compressor, at least one condenser and at least one evaporator. The fresh food compartment 3 and the freezer compartment 4 are examples of storage compartments of a domestic refrigerator intended for storing food and/or beverages and being cooled by the refrigerant circuit.

[0044] The refrigerator 1 comprises an electronic control device 6 which his configured to control the refrigeration circuit as it is generally known in the art. The electronic control device 6 is shown in FIG. 2 and may comprise a microcontroller or a microprocessor 7 and further electronic devices not explicitly shown in the figures. The microprocessor 7 may be attached to a printed circuit board 8 which comprises a first electric contact 9a, a second electric contact 9b, and a third electric contact 9c for contacting the electronic control device 6. The electronic control device 6, in particular its microprocessor 7, is powered by an electric voltage source 10, supplying the electronic control device 6 with an electric voltage, in particular with an electric dc voltage of, for instance, around +5V.

[0045] For the example embodiment shown, the first electric contact 9a of the printed circuit board 8 is connected to the electric voltage source 10 and the second electric contact 9b is connected to ground.
[0046] The domestic refrigerator 1 further comprises a temperature sensor 22 which is shown in Figures 2 and 3. The temperature sensor 22 is configured to measure the actual temperature of the fresh food compartment 3 and the electronic control device 6 is configured to control, particularly to feedback control the refrigeration circuit in response to electric signals of the temperature sensor 22 such that the actual temperature of the fresh food compartment 3 is at least approximately equal to a set temperature. The electric signals of the temperature sensor 22 comprise information about the actual temperature of the fresh food compartment 3. The temperature sensor 22 comprises a first terminal t1 and a second terminal t2.

[0047] The domestic refrigerator 1 may comprise a further temperature sensor which is not explicitly shown and is intended to measure the actual temperature of the freezing compartment 4. The electronic control device 6 may also be configured to control, particularly to feedback control the refrigeration circuit in response to electric signals of the further temperature sensor such that the actual temperature of the freezer compartment 4 is at least approximately equal to a set temperature.

[0048] The domestic refrigerator 1 further comprises a thermally insulated door leaf 11 for opening and closing the fresh food compartment 3 and a further door leaf 12 for opening and closing the freezer compartment 4. The door leafs 11, 12 are pivotally hinged to the housing 2 in particular with respect to a vertical axis.

[0049] The domestic refrigerator 1 may comprise several door shelves 13 arranged on the surface of the door leaf 11 facing towards the fresh food compartment 3.

[0050] The domestic refrigerator 1 may comprise, as it is shown in Fig. 1, several shelves 14 disposed on top of each other within the fresh food compartment 3, a drawer 15 disposed within and at the bottom of the fresh compartment 3, and a further shelve 16 disposed within the freezer compartment 4.

[0051] The domestic refrigerator 1 further comprises an illumination device 23 configured to illuminate the fresh food compartment 3 while the door leaf 11 is open. The illumination device 23 comprises, for instance, at least one light emitting diode (LED) 24 which comprises a cathode C and an anode A.

[0052] The domestic refrigerator 1 further comprises a sensing device 26 configured to determine if the door leaf 11 is opened or closed. In particular, the sensing device 26 is configured to sense a magnetic field produced by a magnet attached to the door leaf 11. The sensing device 26 is, for instance, a magnetic field sensor, for instance, a hall sensor or a magnetic resistance sensor.

[0053] The temperature sensor 22, the illumination device 23 and the sensing device 26 are all attached to a single printed circuit board 27, combining the temperature sensor 22, the illumination device 23 and the sensing device 26 to a single electronic module 21. A top view of the single printed circuit board 27 including the temperature sensor 22, the illumination device 23 and the sensing device 26 is shown in FIG. 3. Additionally, the electronic module 21 may comprise further electronic devices attached to the single printed circuit board 27. The individual electronic devices, such as the temperature sensor 22, the illumination device 23 and the sensing device 26, are electrically connected via conductive tracks 28 of the single printed circuit board 27. The single printed circuit board 27 further comprises a first electric contact 29a, a second electric contact 29b, and a third electric contact 29c. A circuit diagram of the electronic module 21 is shown in FIG. 2.

[0054] The illumination device 23, i.e. the light emitting diode 24 for the present embodiment, is switched on while the door leaf 11 is open, potentially heating the single printed circuit board 27. This may negatively affect the operation of the temperature sensor 22. In order to reduce this potential negative effect, the temperature sensor 22 and the illumination device 23, for instance, the light emitting diode 24 are spaced relatively far apart from each other. Additionally, the temperature sensor 22 may be at least partly thermally insulted from the single printed circuit board 27.

[0055] The single printed circuit board 27 has a length l and a width w. The temperature sensor 22 may be placed in the vicinity of one of the ends of the single printed circuit board 27. The single printed circuit board 27 may have a reduced width w’ around the temperature sensor 22 compared to the width w of the remaining single printed circuit board 27. In accordance with one embodiment of the printed circuit board 27, the width w’ around the temperature sensor 22 may be half of the width w of the remaining single printed circuit board 27.

[0056] For the example embodiment, the electronic module 21 may have been manufactured as shown in FIG. 4 which shows a top view of several, in particular six single printed circuit boards 27 intended for several domestic refrigerators 1. Initially, one printed circuit board is populated with the required electronic devices in order to obtain the several populated printed circuit boards 27. After that, this populated printed circuit board is cut in order to obtain the individual single printed boards 27 which are already populated with the required electronic devices.

[0057] The electronic module 21 is connected to the electronic control device 6 by means of an electric wiring 31 which comprise at one of its ends a connector 32 and at the other end a further connector 33. The connectors 32, 33 are preferably 3-pin RAST connectors. The connector 32 contacts the electric contacts 29a-c of the single printed circuit board 27 and the further connector 33 contacts the electric contacts 9a-c of the printed circuit board 8 of the electronic control device 6 such that the first electric contact 9a of the printed circuit board 8 is electrically connected to the first electric contact 29a of the single printed circuit board 27, the second electric contact 9b of the printed circuit board 8 is electrically connected to the second electric contact 29b of the single printed circuit board 27, and the third electric contact 9c of the printed circuit board 8 is electrically connected to the third electric contact 29c of the single printed circuit board 27. As a result, the electric voltage of the electric voltage source 10 is present at the first electric contact 29a of the single printed circuit board 27 and the second electric contact 29b of the single printed circuit board 27 is connected to ground.

[0058] For the embodiment shown, the electronic module 21 further comprises a controllable switch, in particular a controllable semiconductor switch. This controllable switch may in particular be a transistor 30. The transistor 30 is preferably a bipolar transistor comprising a collector K, an emitter E and a base B.

[0059] For the example embodiment shown, the anode A of the light emitting diode 24 is connected to the first electric contact 29a of the single printed circuit board 27 such that the electric voltage of the electric voltage source 10 is present at the anode A during operation of the domestic refrigerator 1. The cathode C is connected to the collector K of the transistor 30.

[0060] The sensing device 26 needs electric power during operation. A corresponding first contact 26a of the sensing device 26 is connected via a first resistor R1 to the first electric contact 29a of the single printed board 27 providing the sensing device 26 with electric power. A second electric contact 26b of the sensing device 26 is connected to the second electric contact 29b of the single printed circuit board 27 and, thus, to ground.

[0061] The sensing device 26 comprises an output O which is connected via a second resistor R2 to the base B of the transistor 30.

[0062] The emitter E of the transistor 30 is connected to the third electric contact 29c of the single printed board 27 and to the first terminal t1 of the temperature sensor 22. The second terminal t2 of the temperature sensor 22 is connected to ground.

[0063] During operation of the domestic refrigerator 1, the electronic module 21 is operated as following:

[0064] While the door leaf 11 for the fresh food compartment 3 is closed, the sensing device 26 is magnetically coupled with the magnet of the door leaf 11, resulting the sensing device 26 to generate an electric output signal at its output O of 0V or at least of such a low voltage such that the transistor 30 is switched to its non-conducting state. Therefore, the sensing device 26 controls the controllable switch to be opened while the door leaf 11 is closed. Since during this state the transistor 30 is in its non-conducting state, no electric current flows through the light emitting diode 24. The light emitting diode 24 is therefore switched off.

[0065] The first terminal t1 of the temperature sensor 22 is connected to the third electric contact 29c of the single printed circuit board 27 and, thus, to the third electric contact 9c of the printed circuit board 8 of the electronic control device 6. While the door leaf 11 is closed, the electronic control device 6, in particular its microprocessor 7 switches the electric voltage of the voltage supply 10 or another voltage source to the third contact 9c of the printed circuit board 8 causing an electric current flowing through the temperature sensor 22. For the example embodiment shown, the temperature sensor 22 is designed to have a temperature depending resistance, allowing the electronic control device 6 to estimate the temperature of the temperature sensor 22, which is thermally coupled with the fresh food compartment 3, by evaluating the electric current flowing through the temperature sensor 22, by means, for instance, of a current measuring device not explicitly shown in the figures.

[0066] The domestic refrigerator 1 is further designed not to measure the temperature of the fresh food compartment 3 continuously, but only during discrete time intervals. This measurement can be carried out periodically. For the example embodiment shown, the time needed for measuring the temperature compared to the time no temperature measurement is carried out is relatively short. While no temperature measurement is carried out, the electric voltage is not switched to the third electric contact 9c of the printed circuit board 9c and the electric voltage at the third electric contact 9c is monitored by the electronic control device 6.

[0067] As long as the door leaf 11 is closed and no temperature measurement is carried out, the electric voltage measured at the third electric contact 9c is 0V or at least relatively low. As soon as the door leaf 11 is opened, its magnet and the sensing device 26 are not magnetically coupled anymore, causing the sensing device 26 to generate an output signal at its output O which is sufficient to switch on the controllable switch, i.e. to switch the transistor 30 to its conducting state. As a result, an electric voltage will be present at the emitter E of the transistor 30 and, thus, an electric voltage will be present at the third electric contact 9c of the printed circuit board 8 of the electronic control device 6. This electric voltage is slightly lower than the electric voltage present at the anode A of the light emitting diode 24, however is significantly greater than the voltage while the door leaf 11 is closed. As a result, the electronic control device 6 can conclude that the door leaf 11 is open and switches a driving circuit not explicitly shown in the figures to the third electric contact 9c. The driving electric circuit is preferably an electric current sink making sure that a constant electric current can flow through the light emitting diode 24 and the transistor 30 while the door leaf 11 is open. Then, the light emitting diode 24 emits light for illuminating the fresh food compartment 3.

[0068] While the door leaf 11 is open, temperature measurement of the fresh food compartment 3 is suspended.

[0069] When the door leaf 11 is closed again, its magnet is magnetically coupled with the sensing device 26, causing it not to generate the output signal at its output. Then, the transistor 30 is switched off again and no or only a low electric voltage is present at the third electric contact 9c of the single printed circuit board 27. The electronic control device 6 can conclude that the door leaf 11 is closed and, thus, switches the driving circuit off and re-establish the temperature measurement of the fresh food compartment 3.

[0070] It is also possible to connect the controllable switch, i.e. the transistor 30 between the illumination device 23 and the first resistor R1, i.e. for the present embodiment to connect, for instance, the emitter E of the transistor 30 to the anode A of the light emitting diode 24 and the collector K to the terminal of the first resistor R1 which is connected to the first electric contact 29a of the single printed circuit board 27. Then, the cathode C of the light emitting diode 24 is connected to the first terminal t1 of the temperature sensor 22 and to the third electric contact 29c of the single printed circuit board 27.

[0071] For the example embodiment shown, the electronic module 21, i.e. the single printed circuit board 27 populated with the electronic devices is attached to or into one of the side walls of the fresh food compartment 3. In particular, the populated single printed circuit board 27 is mounted into a cavity or recess 50 of one of the side walls of the fresh food compartment 3. This may be realized by deep-drawing the recess 50 into the surface or liner 51 of the relevant side wall. For the example embodiment, however, an aperture 52 was cut into the surface or liner 51 of the relevant sidewall and a separate device 53, which includes the recess 50, was attached into this aperture 52. This separate device 53, which is preferably made from plastics, including the single printed circuit board 27 and a part of the liner 51 including the aperture 52 is shown as an exploded view drawing in Fig. 5.

[0072] The recess 50 is closed by a cover 54. The cover 54 is made from plastics and/or is fastened to the device 53 by means of snaps.

[0073] For the example embodiment shown, the electronic control device 6 is attached to the housing 2 remotely from the populated single printed circuit board 27. In order to connect the populated single printed circuit board 27 with the electronic control device 6, for instance, by means of the electric wiring 31, the separate device 53 comprises an aperture 55 through which the electric wiring 31 is lead through.

[0074] As mentioned above, the single printed circuit board 27 may comprise further electronic devices. An example of a further electronic device is a humidity sensor 61 which is intended to measure the humidity or the relative humidity within the fresh food compartment 3. FIG. 6 shows an example circuit which comprises such a humidity sensor 61.

[0075] The humidity sensor 61 is also attached to the single printed circuit board 27 and is connected to a fourth electric contact 29d and fifth electric contact 29e. For this embodiment, the connectors 32, 33 are 5-pin RAST connectors and the printed circuit board 8 of the electronic control device 6 comprises also a fourth electric contact 9d and fifth electric contact 9e an alternative which may be connected to the microprocessor 7. The fourth electric contact 9d of the printed circuit board 8 is electrically connected to the fourth electric contact 29d of the single printed circuit board 27, and the fifth electric contact 9e of the printed circuit board 8 is electrically connected to the fifth electric contact 29e of the single printed circuit board 27, allowing the microprocessor 7 to evaluate the signals from the humidity sensor 61.

[0076] FIG. 7 shows an alternative embodiment of the electronic module 21 which also comprises a single printed circuit board 77 and several electronic devices, including the temperature sensor 22, the illumination device 23, in particular the light emitting diode 24, and the sensing device 26. Further electronic devices, for instance, the humidity sensor 61, can also be included. The electronic module shown in FIG. 7 is denoted by the reference sign 71. FIG. 8 shows the corresponding circuit diagram of the electronic module 71.

[0077] The single printed circuit board 77 comprises a first electric contact 79a, a second electric contact 79b, a third electric contact 79c, a fourth electric contact 79d, and a fifth electric contact 79e. The single printed circuit board 77 may also comprises a sixth electric contact 79f, as shown in FIG. 8.

[0078] The electronic module 71 is connected to the electronic control device 6 by means of an electric wiring 73 which comprises at one of its ends a connector 72 and at the other end a further connector not explicitly shown in the figures. These connectors 72 are preferably 5-pin RAST connectors or 6-pin RAST connectors, depending on the number of electric contacts 79a-f. The connector 72 contacts the electric contacts 79a-f of the single printed circuit board 77 and the further connector contacts electric contacts of the electronic control device 6.

[0079] The electronic module 71 is powered via the wiring 73, particularly in such a way that the voltage of the voltage source 10 is present at the first electric contact 79a. The third electric contact 79c is connected to ground.

[0080] For the example embodiment shown in figures 7, 8, the anode A of the light emitting diode 24 is connected to the first electric contact 79a and the cathode C is connected to the fourth electric contact 79d. The first terminal t1 of the temperature sensor 22 is connected to the fifth electric contact 79e and the second terminal t2 of the temperature sensor 22 is connected to ground.

[0081] The sensing device 26 needs electric power during operation. The corresponding first contact 26a of the sensing device 26 is connected via a resistor R to the first electric contact 29a and the second contact 26b of the sensing device 26 is connected to the third electric contact 79b of the single printed circuit board 77, and, thus, to ground. The output O of the sensing device 26 is connected to the second electric contact 79b. The sixth electric contact 79f is not used for the shown embodiment. This contact may be used for the humidity sensor 61, if present.

[0082] During operation of the domestic refrigerator 1, the electronic module 71 is operated as following:

[0083] While the door leaf 11 is closed, its magnet is magnetically coupled with the sensing device 26 and while the door leaf 11 is open, the magnet is not sufficiently coupled with the sensing device 26, causing output signals at the output O depending on the state of the door leaf 11. The output O is connected to the electronic control device 6 via the wiring 73. Thus, the electronic control device has information about the state of the door leaf 11.

[0084] While the door leaf 11 is closed, the control device 11 switches off power for the light emitting diode 24. While the door leaf 11 is open, the electronic control device 6 supplies electric power to light emitting diode 24.

[0085] The control device 6 may also be configured to only measure the temperature of the fresh food compartment 3 by means of the temperature sensor 22 while the door leaf 11 is closed.

[0086] The domestic refrigerator 1 may further be designed not to measure the temperature of the fresh food compartment 3 continuously, but only during discrete time intervals. This measurement can be carried out periodically. For the example embodiment shown, the time needed for measuring the temperature compared to the time no temperature measurement is carried relatively short.

LIST OF REFERENCE SIGNS
1 domestic refrigerator
2 housing
3 fresh food compartment
4 freezer compartment
5 divisional wall
6 electronic control device
7 microprocessor
8 printed circuit board
9a-c electric contact
10 electric voltage source
11, 12 door leaf
13 door shelves
14 shelves
15 drawer
16 shelve
21 electronic module
22 temperature sensor
23 illumination device
24 light emitting diode
26 sensing device
26a, b contact
27 single printed circuit board
28 conductive tracks
29a-e electric contacts
30 transistor
31 wiring
32, 33 connector
50 recess
51 liner
52 aperture
53 device
54 cover
55 aperture
61 humidity sensor
71 electronic module
72 wiring
73 wiring
77 single printed circuit board
79a-f electric contact
A anode
B base
C cathode
E emitter
K collector
• output
l length
t1, t2 terminal
w, w’ width