EP2539912A1

EP2539912A1 - Circuit assembly for operating a household appliance and corresponding method

Info

Publication number: EP2539912A1
Application number: EP11703180A
Authority: EP
Inventors: Holger Helmschmidt; Günter GIETL; Martin Bischoff; Sebastian Evard; Lothar Knopp; Guido Sattler; Károly ZARUBA
Original assignee: BSH Bosch und Siemens Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2010-02-24
Filing date: 2011-02-02
Publication date: 2013-01-02
Anticipated expiration: 2031-02-02
Also published as: EA201290762A1; CN102770934B; WO2011104073A1; EA022259B1; CN102770934A; DE102010002277A1; EP2539912B1; PL2539912T3

Abstract

The present invention relates to a circuit assembly 2 for operating a household appliance 1, comprising: a circuit input 4 for applying an AC supply voltage U_v, a control device 3 for controlling operating processes of the household appliance 1, a voltage supply unit 10 coupled to the control device 3 for providing a DC operating voltage UB for the control device 3 from the AC supply voltage, an operator-actuatable pushbutton 18 by means of which the voltage supply unit 10 can be coupled to the circuit input 4, and an electric switch 11 connected in parallel to the pushbutton 18. The electric switch can be switched by the control device 3 between an electrically conductive switch state in which the voltage supply unit 10 is coupled to the circuit input 4 and an electrically disabling switch state, wherein the circuit assembly 2 comprises a state detection device 23 which is coupled to the pushbutton 18 and the control device 3 and is designed to detect a switch state of the pushbutton 18 and to output a state signal 26 that reflects the switch state of the pushbutton 18 to the control device 3, wherein the control device 3 is designed to switch the electric switch 11 in accordance with the state signal 26, and at least partially electrically decouples the state detection device 23 from the electric switch 11 by means of a decoupling device 12 connected between the electric switch 11 and the state detection device 23.

Description

Circuit arrangement for operating a household appliance and corresponding method

The invention relates to a circuit arrangement for operating a household appliance. It comprises a circuit input for applying an alternating supply voltage, a control device for controlling operating processes of the domestic appliance, as well as a voltage supply unit coupled to the control device - for example a power supply - for providing a DC operating voltage for the control device, namely from the AC supply voltage. The circuit arrangement also comprises an operator-actuatable push-button, via which the power supply unit can be coupled to the circuit input. The circuit arrangement also includes an electrical switch connected in parallel with the pushbutton. This can be switched by the control device between an electrically conductive switching state, in which the voltage supply unit is coupled via this switch to the circuit input, and an electrically blocking switching state. The invention also relates to a corresponding method for operating a domestic appliance.

Such circuit arrangements and methods are already known from the prior art, namely, for example, from the publications WO 2009/071412 A1 and DE 10 2007 058 380 A1. The first document describes an electronic circuit with a button, with the help of an operator can turn on the household appliance. A coil of an impulse relay is energized via the pushbutton, so that a power supply unit via the same relay is coupled after actuation of the pushbutton with a circuit input and thus with an electrical supply network. The relay can be opened by a control device again, by controlling a triac connected in parallel with the pushbutton. On the one hand, it is thus ensured that the domestic appliance can be switched off by the control device after completion of an operating process and thus can no longer absorb electrical energy; On the other hand, by using a bistable relay an already started operating process can be completed properly after failure and return of the mains voltage. In the subject matter according to DE 10 2007 058 380 A1, the power supply is even supplied with electrical energy via two separate electrical switches, which are actuated and closed after actuation of the button, namely by a control device. One of the electrical switches is a bistable relay and also serves to lock a door of the domestic appliance. The other switch is a monostable relay, which is closed by the controller immediately after pressing the button. Both switches can be opened after completion of an operation process of the domestic appliance, and the domestic appliance consumes no electrical energy. It is an object of the invention to show a way how the functionality of a circuit arrangement of the type mentioned can be extended in comparison to the prior art.

This object is achieved by a circuit arrangement as well as by a domestic appliance and by a method having the features of the respective independent claim. Advantageous embodiments of the invention are the subject of the dependent claims and the following description. Advantageous embodiments of the invention according to each of the categories of circuit arrangement, domestic appliance and method correspond to advantageous embodiments according to the respective other categories, even if this is not explicitly mentioned herein.

A circuit arrangement according to the invention for operating a domestic appliance comprises a circuit input for applying a supply alternating voltage, a control device for controlling operating processes of the domestic appliance, a voltage supply unit coupled to the control device for providing a DC operating voltage for the control device from the AC supply voltage, a pushbutton actuatable by an operator via which the voltage supply unit can be coupled to the circuit input, and an electrical switch connected in parallel with the switch, which can be switched by the control device between an electrically conductive switching state in which the voltage supply unit is coupled to the circuit input and an electrically blocking switching state. The circuit arrangement comprises a state detection device coupled to the pushbutton and the control device, which detects a switching state of the button and outputs a switching state reproducing this state signal to the control device. The control device can switch the electrical switch depending on the status signal. Furthermore, a decoupling device is connected between the electrical switch and the state detecting device. Such a decoupling device can serve to at least partially decouple the state detection device electrically from the electrical switch.

For a complete electrical decoupling of the state detection device from the electrical switch, the decoupling device may preferably have a diode whose cathode is coupled to the electrical switch and whose anode is connected to the state detection device. Additionally or alternatively, the decoupling device may have an ohmic resistance.

The functionality of the circuit arrangement in comparison with the prior art is thus improved by a separate from the power supply unit state detection device which detects the respective instantaneous switching state of the probe and outputs a status signal to the control device. This status signal characterizes the switching state of the button. It is further ensured by the decoupling device that - when the electrical switch is closed - the state detection device of the electrical supply network is at least partially electrically decoupled and the state signal is thus not corrupted. There are thus a clear detection of the instantaneous switching state of the button and a clear detection of an actuation of the button possible.

An operator can thus operate the button to turn off the home appliance. The control device then receives quasi a switch-off and can bring the electrical load, as well as other components of the household appliance in a safe state and then open the electrical switch to disconnect the domestic appliance from the electrical supply network. The switching off of the domestic appliance is thus - in contrast to the subject matter in accordance with publication WO 2009/071412 A1 - via the control device; the electrical switch can not be independent of the Control device to be opened. This increases the reliability of the household appliance. Namely, the control device can bring the components of the domestic appliance to a safe state or switch them off properly before it disconnects itself and the entire household appliance from the supply network.

As a state signal, the state detection device can provide an electrical voltage and output to the control device. The electrical voltage may have at least a first property in an open switching state of the probe and at least one second property in a closed, ie actuated switching state of the probe. A property may be, for example, an amplitude value or a frequency value here. The state detection device may be coupled to an electrical contact element of the probe; then the state detection device is coupled in the closed switching state of the button to the electrical supply network, namely via the button. The state detection device can also be coupled to a DC voltage source, in particular to a DC voltage provided by the voltage supply unit, that is to say, for example, the DC operating voltage. The state detection device may include passive and / or active electronic components. It may have, for example, at least one diode and / or at least one transformer and / or at least one optocoupler and / or at least one ohmic resistor. In an embodiment of the invention, the state detection device may comprise, for example, an ohmic resistor or a series of resistors which are connected on the one hand to an electrical contact element of the probe and on the other hand to a detection input of the control device. The detection input may also be coupled via a parallel connection of an ohmic resistor and a first diode to a DC voltage source. Here, the cathode of the first diode may be coupled to the DC voltage source and its anode coupled to the detection input. The detection input may also be coupled via a parallel circuit to an ohmic resistance and a second diode to a reference potential, wherein preferably the cathode of the second diode are coupled to the detection input and its anode to the reference potential. In such an embodiment of the state detection device, a fraction of the DC voltage provided by the DC voltage source is present at the detection input of the control device in the open switching state of the button, namely, for example, two volts, three volts, four volts or five volts. In the closed switching state of the probe, the DC voltage of the DC voltage cases overlaps with a fraction of the AC supply voltage (mains voltage) and there is a pulsating electrical voltage at the detection input of the control device. This changes between two amplitude values, namely with the frequency of the alternating supply voltage. For example, this voltage may alternate between a first amplitude value of 2 volts and a second amplitude value of 5 volts.

By providing an electrical voltage as a state signal, which has at least a first and a second characteristic, the control device can clearly and without much computational effort recognize in which switching state the button is currently located. If the property of the electrical voltage changes, this can be detected directly at the detection input of the control device and the control device can close or open the electrical switch.

After detecting an actuation of the button on the basis of the state signal, the control device can change the switching state of the electrical switch. In particular, after detecting an actuation of the button in the conductive switching state of the electrical switch, the control device can switch the same switch into the electrically blocking switching state. This makes it possible to switch off the household appliance with the aid of the button. Before the control device opens the electrical switch, it can switch off at least one electrical consumer of the household appliance properly and thus bring it into a safe state. As already stated, faulty states of components of the domestic appliance are thus avoided.

In one embodiment, the control device opens the electrical switch after completing an operating process of the domestic appliance. It is thus possible to reduce the energy consumption of the household appliance as a whole to a minimum. The household appliance does not absorb any electrical energy after completing an operating process.

The electrical switch, with the aid of which the push button can be bridged, is preferably a bistable relay, that is to say, for example, an impulse relay, an adhesive relay or a similar relay. So the electrical switch is preferably one Switch, which has two mechanically stable switching states. He can thus maintain the conductive or blocking switching state, namely without a continuous control by the control device. The electrical switch is preferably switchable by applying a pulse of current between the conductive and the blocking switching state. By using a bistable relay, it is possible to properly complete an already started operating process of the domestic appliance even after such a power failure, which lasts a relatively long period of time. In an alternative embodiment, the electrical switch is a monostable relay or a semiconductor switch. In this embodiment, the electrical switch remains in its electrically conductive switching state only during the control or the energy supply from the side of the control device. The circuit arrangement can have an electrical energy store coupled to the electrical switch. Then, the electrical switch to maintain the conductive switching state can be supplied with electrical energy from the energy storage, namely in particular when the AC supply voltage (mains voltage) fails for a relatively short period of time. This embodiment proves to be particularly advantageous in particular in the embodiment in which the electrical switch is a simple, ie monostable relay or a semiconductor switch. If the AC supply voltage and thus also the DC operating voltage for the control device fails for a relatively short period of time, the electrical switch takes up the energy stored in the energy store in order to maintain its conductive switching state. The use of an energy storage also allows - especially in a monostable relay or a semiconductor switch - a safe shutdown of the household appliance in the event of a prolonged power failure and although the controller can turn off the component of the domestic appliance properly after detecting the failure of the AC supply voltage. Subsequently, the electric switch can also open, namely in particular by discharging the energy store. This can be achieved, for example, by short-circuiting the energy store to a reference potential. The control device can namely with electrical energy from the energy storage and / or energy from another energy storage, for example a DC link capacitor to be supplied after failure of the AC supply voltage.

The electrical switch, namely its control input - can be coupled to the power supply unit and / or with the button. Then, when the button is pressed by an operator, the electrical switch is almost automatically closed. Thus, the closing of the electrical switch is independent of the control device, the control device does not have to be "started up" so that the electrical switch is closed, the electrical switch is thus switched much faster than by means of the control device in its electrically conductive switching state For example, the switch can be coupled to that output of the voltage supply unit to which the operating DC voltage for the control device or a further DC voltage is provided a rectifier - in particular a rectification diode - and / or at least one ohmic resistor and / or at least one capacitor Circuit arrangement or a preferred embodiment of this circuit arrangement.

A household appliance is understood to mean a device that is used for household management. This may be a large household appliance, such as a washing machine, a tumble dryer, a dishwasher, a cooking appliance, a cooker hood, a refrigerator, a Kühlgefrier combination or an air conditioner. But this can also be a small household appliance, such as a coffee machine or a food processor. In a method according to the invention for operating a domestic appliance with a circuit arrangement, operating processes of the domestic appliance are controlled by a control device. An AC supply voltage is applied to a circuit input of the circuit arrangement. A voltage supply unit coupled to the control device is connected to the circuit input via a Button coupled. The voltage supply unit provides a DC operating voltage for the control device from the AC supply voltage. It is connected in parallel to the switch electrical switch between an electrically conductive switching state, in which the power supply unit is coupled to the circuit input, and an electrically blocking switching state by the control device. A switching state of the button is detected by means of a coupled to the button and the control device state detection device, and the switching state of the button reproducing state signal is output by the state detection device to the control device. The control device switches the electrical switch depending on the status signal. Furthermore, the state detection device is at least partially electrically decoupled from the electrical switch by means of a decoupling device connected between the electrical switch and the state detection device. The preferred embodiments presented with reference to the circuit arrangement according to the invention and their advantages apply correspondingly to the domestic appliance according to the invention and to the method according to the invention.

Further features of the invention will become apparent from the claims, the figures and the description of the figures. All the features and feature combinations mentioned above in the description as well as the features and feature combinations mentioned below in the description of the figures and / or shown alone in the figures can be used not only for the respectively specified combination but also in other combinations or also alone.

The invention will now be explained in more detail with reference to individual preferred embodiments, as well as with reference to the accompanying drawings.

Show it:

1 shows a schematic representation of a domestic appliance with a circuit arrangement according to a first embodiment; 2 shows a schematic representation of a domestic appliance with a circuit arrangement according to a second embodiment;

3 to 8 each show in schematic representation an example of a control part of an electrical switch of the circuit arrangement;

9 is a schematic representation of another example of a control part of an electrical switch of the circuit arrangement;

10 to 12 in schematic representation in each case an example of a

Decoupling device of the circuit arrangement;

13 is a schematic representation of a state recognition device of

Circuitry;

14 is a schematic representation of a circuit arrangement according to a third embodiment with a further

State detecting means.

A domestic appliance 1 shown in FIG. 1 comprises a circuit arrangement 2. The circuit arrangement 2 serves to operate a household appliance 1. It comprises a control device 3 which serves to control operating processes of the domestic appliance 1. For example, the controller may control the operating processes in accordance with stored operating programs. In the control of the operating processes, the control device 3 controls at least one electrical load of the domestic appliance 1. The control device 3 may include a microcontroller and / or a digital signal processor and / or a memory.

The circuit arrangement 2 comprises a circuit input 4 with a first input connection 5 and a second input connection 6. A supply alternating voltage U _{v can be} applied between the input connections 5, 6. The AC supply voltage U _v is the mains voltage of an external electrical supply network. The circuit input 4 can be coupled to the electrical supply network, namely via a mains filter and a cable. Of the first input terminal 5 is connected to a phase conductor 7, and the second input terminal 6 is connected to a neutral conductor 8 (zero conductor).

By contrast, the control device 3 is connected to a reference potential 9, which is galvanically isolated from the circuit input 4. The reference potential 9 is thus a different potential from the potential provided at the neutral conductor 8.

The circuit arrangement 2 comprises a voltage supply unit 10, which may comprise a power supply unit. It may, for example, have a switched-mode power supply and / or a capacitor power supply. The voltage supply unit 10 serves to provide from the AC supply voltage U _v a DC operating voltage U _B , namely with respect to the reference potential 9. The amplitude of the DC operating voltage U _B may, for example, in a range from 2 volts to 9 volts. It can be for example 5 volts.

The power supply unit 10 is connected to the neutral conductor 8. In addition, the voltage supply unit 10 can be coupled to the first input terminal 5, namely via an electrical switch 1 1. Between the electrical switch 1 1 and the power supply unit 10, a decoupling device 12 is integrated in the phase conductor 7.

In principle, the electrical switch 1 1 may be a semiconductor switch. In the exemplary embodiment, the switch 1 1 is a relay, so for example a bistable relay or a simple monostable relay. The switch 1 1 comprises two contact elements, namely a movable contact element 13, as well as a stationary contact element 14. If the movable contact element 13 brought into contact with the stationary contact element 14, an electrical connection between the first input terminal 5 and the power supply unit 10 is made , The electrical switch 1 1 also comprises a control part 15, which is coupled in the exemplary embodiment via a first control line 16 and a second control line 17, each with a control output of the control device 3. Via the control lines 16, 17, the control device 3, the electric switch 1 1 drive. The circuit arrangement 2 also has a button 18, which can be actuated by an operator of the domestic appliance 1. The button 18 includes an operating element 19, as well as in the embodiment of FIG. 1, two electrical switches 20, 21st If the operating element 19 is actuated by an operator, the switches 20, 21 are closed for the duration of the actuation. The switches 20, 21 thus remain in the closed switching state during the actuation of the operating element 19. Via the switch 21, the voltage supply unit 10 can be coupled to the first input terminal 5, namely via the decoupling device 12. Namely, the switch 21 is connected firstly to the first input terminal 5 and on the other hand connected via the decoupling device 12 to the power supply unit 10.

Via the switch 20, the first input terminal 12 can be coupled to an input 22 of a state detection device 23. An output 24 of the state detection device 23 is connected to a detection input 25 of the control device 3.

The state detection device 23 has the functions of detecting a switching state of the button 18. Namely, the input 22 via the switch 20 of the button 18 to the circuit input 4 can be coupled. Thus, when the button 18 is actuated, the supply AC voltage U _v is applied to the input 22. The state detection device 23 converts this alternating supply voltage U _v into a state signal 26 and outputs the state signal 26 to the control device 3, namely at its detection input 25. The state signal 26 can have different properties, for example, depending on whether the button 18 is currently actuated or not. In the non-actuated state of the button 18, ie in the open state of the switch 20, the status signal 26 may have a first property, such as a first amplitude value and / or a first frequency value. In the actuated state of the button 18, the status signal 26 may have at least one second property, such as a second amplitude value and / or a second frequency value.

Based on the status signal 26, the control device 3 can detect whether an actuation of the button 18 is present or not. If the button 18 is turned off State of the domestic appliance 1 - so when the electric switch 1 1 is open - operated, the control device 3 closes the electrical switch 1 1. This bypasses the button 18, which can be released by the operator. The power supply unit 10 generates the DC operating voltage U _B and the domestic appliance 1 is turned on. The control device 3 can control the operating processes of the domestic appliance 1. After completion of an operating process, the control device 3 finds the switch 1 1, so that the voltage supply unit 10 is decoupled from the circuit input 4. The household appliance 1 is switched off. If the button 18 in the on state of the domestic appliance 1 - that is, when the switch 1 1 is closed - operated, so detects the control device 3 selbige actuation. After detecting the operation, the control device 3 brings all electrical consumers of the domestic appliance 1 in a safe state; namely the electrical consumers are switched off properly. The control device 3 then opens the electric switch 1 1, and the domestic appliance 1 is turned off.

In Fig. 13, an example of the state detecting device 23 is shown. Between the input 22 and the output 24, a series of resistors 27 is connected, namely, for example, a series of three ohmic resistors 27. The output 24 is also coupled via a parallel circuit of an ohmic resistor 28 and a diode 29 to a DC voltage source. In the example, this is the voltage supply unit 10, so that the output 24 is coupled via the said parallel circuit with the operating DC voltage U _B. On the other hand, the output 24 is coupled via a parallel connection of a second diode 30 and a further ohmic resistor 31 to the reference potential 9. The cathode of the first diode 29 is connected to the DC voltage source and the anode of the first diode 29 to the output 24; the cathode of the second diodes 30 is connected to the output 24 and its anode to the reference potential 9. The status signal 26 is in the example an electrical voltage U _z . The voltage U _z may have the following properties: If the button 18 is not actuated, then the input 22 is free of the supply alternating voltage U _v - At the output 24 is a fraction of the DC operating voltage U _B on. In the non-actuated state of the probe 18, the amplitude of the voltage U _{z is} equal to a fraction of the amplitude of the DC operating voltage U _B and may for example be two volts or three volts. In the non-actuated state of the button 18, the voltage U _{z is} a DC voltage. in the actuated state of the probe 18, however, is applied to the input 22, the AC supply voltage U _v , and a fraction of it is superimposed with the DC operating voltage U _B. The voltage U _z thus alternates between a first and a second amplitude value, namely for example between two volts and five volts. The voltage U _z changes with the frequency of the supply AC voltage U _v - In such a manner, the controller 3 can reliably, clearly and quickly recognize whether the button 18 has been pressed or not. The detection can be in both an open as well as closed switch 1 1, as at the input 22 only when pressed button 18 via the then closed contact element 20, a signal is applied, ie there is no repercussions on this signal when the contact element 13 is closed.

FIG. 2 shows the domestic appliance 1 with the circuit arrangement 2 according to a further embodiment of the invention. The circuit arrangement 2 according to FIG. 2 substantially corresponds to that according to FIG. 1 - in the following, only the differences will be discussed in greater detail. The circuit arrangement 2 comprises an electrical energy store 32, which can be used functionally. The energy store 32 may comprise, for example, a capacitor which is connected between the control line 16 and the reference potential 9. So the energy storage 32 is coupled to the switch 1 1. In addition, the circuit arrangement 2 according to FIG. 2 comprises a branching unit 33, which is connected between the energy store 32 and the control device 3 and is additionally coupled to the voltage supply unit 10. The branching unit 33 can, for example, include a circuit node which connects the control device 3, the energy store 32 and the voltage supply unit 10 to one another. The branching unit 33 thus picks up the DC operating voltage U _B.

In the example of FIG. 2, a single control line 16 is provided between the switch 1 1 and the control device 3.

Another difference is that the button 18 comprises a single switch 20, via which both the state recognition device 23 and the decoupling device 12 are coupled to the first input terminal 5 can. For this purpose, the decoupling device 12 is connected directly to the input 22 of the state recognition device 23.

The features and feature combinations referred to in FIG. 1 as well as the features and feature combinations mentioned in relation to FIG. 2 can be combined as desired.

By using the energy storage 32, the switch 1 1 can also be kept in the closed switching state when the AC supply voltage Uv fails. With electrical energy from the energy storage 32, the closed state of the switch 1 1 can be maintained for a certain period of time. This proves to be particularly helpful in a monostable relay as well as a semiconductor switch. If necessary, the control device 3 can also be supplied with electrical energy from the energy store 32, namely after a failure of the supply alternating voltage U _v . For this purpose, however, a further store can also be used.

By tapping the operating DC voltage U _B or another DC voltage through the branching unit 33, the electrical switch 1 1 can be spent immediately after pressing the button 18 in its electrically conductive switching state. This is then done independently of the control device 3. After pressing the button 18, the branching unit 33 accesses namely the DC operating voltage U _B or the other DC voltage to the power supply unit 10 and the control part 15 of the switch 1 1 is energized without it being driven by the control device. 3 requirement. Thus, the switch 1 1 is closed much faster than without the connection to the power supply unit 10th

The circuit arrangement 2 according to the embodiment shown in FIG. 2 can also be designed without an energy store 32 and the branching device 33. In this case, the control part 15 of the switch 1 1 is controlled by the control device 3.

An example of the decoupling device 12 is shown in FIGS. 10 to 12. It comprises a first connection 12a, which is connected to the pushbutton 18, one second terminal 12 b, which is connected to the switch 1 1, and a third terminal 12 c, which is connected to the power supply unit 10. As shown in Fig. 10, the decoupler 12 may include a diode 34 having its anode connected to the first terminal 12a and its cathode connected to the terminals 12b, 12c. In the example according to FIG. 12, the decoupling device 12 additionally comprises a further diode 35 whose anode is connected to the second terminal 12b and whose cathode is connected to the cathode of the diode 34 and the third terminal 12c. In the example according to FIG. 11, the diode 34 is replaced by an ohmic resistor and / or an NTC (Negative Temperature Coefficient) and / or a PTC (Positive Temperature Coefficient) 36. Such an embodiment of the decoupling device 12, as shown in FIGS. 10 to 12, enables an electrical decoupling of the state detection device 23 from the switch 1 1. Thus, the supply AC voltage U _v does not affect the state signal 26 in the closed state of the switch 1 1 so that an actuation of the button 18 can be clearly recognized. This applies in particular to the circuit arrangement 2 according to FIG. 2, in which the decoupling device 12 is connected directly to the input 22 of the state detection device 23. In the circuit arrangement 2 according to FIG. 1, the switch 21 of the button 18 also takes over the decoupling of the state detection device 23 from the switch 1 1. The decoupling device 12 according to FIGS. 11 and 12, namely with the diode 35, also serves to rectify the AC supply voltage U _v .

In FIGS. 3 to 8, examples of the control part 15 of the switch 11 are shown. As already stated, the switch 1 1 may be a bistable relay, a simple monostable relay or a semiconductor switch. FIG. 3 shows a control part 15, as can be used in the circuit arrangement 2 according to FIG. 1. In this example, the switch 1 1 is a bistable relay, ie it has two mechanically stable switching states. The control part 15 comprises a first coil 37 and a second coil 38. The first coil 37 is connected via the control line 16 to the control device 3; On the other hand, the first coil 37 is connected to the reference potential 9. The second coil 38 is on the one hand connected to the control device 3, namely via the second control line 17; On the other hand, it is connected to the reference potential 9. By energizing the first coil 37 with a current pulse, the switch 1 1 can be closed, and the movable contact element 13 comes into contact with the stationary contact element 14. By applying the second coil 38 with a current pulse of the switch 1 1 is opened.

In the example of FIG. 4, the electrical switch 1 1 is a bistable latching relay. The control part 15 includes a single coil 39, which is coupled on the one hand via the control line 16 to the control device 3 and on the other hand to the reference potential 9. By applying the coil 39 with a current pulse, the switch 1 1 can be switched between the closed and the open switching state.

In the example of FIG. 5, the control part 15 includes a single coil 40. Here, the switch 1 1 is a simple monostable relay. The movable contact element 13 is thus only in contact with the stationary contact element 14 when electrical current flows through the coil 40. The coil 40 is thus continuously energized by means of the control device 3 for maintaining the closed switching state of the switch 1 1. Especially in this embodiment, the use of energy storage 32 (FIG. 2) is particularly advantageous. Electric current also flows through the coil 40 when the alternating supply voltage U _v fails for a short period of time. The closed switching state of the switch 1 1 can thus be maintained.

The switch 1 1 is a bistable relay with two coils 37, 38. The coils 37, 38 are here on the one hand with the DC operating voltage U _B and on the other hand in each case with the collector an NPN bipolar transistor 41, 42 coupled. The respective emitters of the bipolar transistors 41, 42 are connected to the reference potentials 9. The base of the bipolar transistor 41 is coupled to the control device 3 via the control line 16, and the base of the bipolar transistor 42 is connected to the control device 3 via the control line 17. Thus, the control of the switch 1 1 using the bipolar transistors 41, 42 takes place.

The electrical switch 1 1 of FIG. 7 is also a bistable relay. It comprises a coil 43 which - depending on the current direction of a current pulse - attracts or pushes away the movable contact element 13. For this purpose, the coil 43 on the one hand with a Switch 44 and on the other hand connected to a switch 45. The switches 44, 45 can be realized as transistors. On both sides, the coil 43 via the respective switch 44, 45 either with the reference potential 9 or with a DC voltage - for example, the DC operating voltage U _B - are connected. Thus, the current direction can be controlled by the coil 43: If the coil 43 is coupled via the switch 45 with the DC operating voltage U _B and the switch 45 to the reference potential 9, the current flows in a first direction; however, if the coil 43 is coupled via the switch 44 to the reference potential 9 and via the switch 45 to the DC operating voltage U _B , then the current flows in the second direction. If the coil 43 is coupled to the reference potential 9 on both sides, then no current flows.

The switch 1 1 according to FIG. 8 substantially corresponds to that according to FIG. 6, wherein the base of the bipolar transistor 41 responsible for closing the movable contour element 13 is coupled via an ohmic resistor 46 to a DC voltage source which provides a DC voltage V. The DC voltage V can also be the DC operating voltage U _B or a separate DC voltage. The DC voltage V is provided by the power supply unit 10 (FIGS. 1 and 2). Such a design ensures that the switch 1 1 is automatically closed immediately after pressing the button 18, namely independently of the control device. 3

FIG. 14 shows a modification of the circuit arrangement 2 shown in FIG. 2 with a further state detection device 23 and with the decoupling device 12 shown in FIG.

In the state detecting device 23 of this modification, an ohmic resistor 27 and a diode 52 are connected in series between the input 22 and the output 24. Furthermore, the output 24 is coupled via a parallel connection of a further ohmic resistor 31 to the reference potential 9. The cathode of the diode 52 is connected to the ohmic resistor 27 and the anode of the diode 52 to the input 22. The ohmic resistors 27 and 31 represent a voltage divider and are designed such that at the output 24, the state signal 26 can not exceed a permissible for the input 25 of the control unit 3 maximum voltage. The diode 52 serves as a "one-way" rectifier circuit, ie that the negative Half-waves of applied to the inputs 5 and 6 AC voltage U _{v be} cut off. In this example, the status signal 26 is therefore always a positive electrical voltage U _z , which can be easily evaluated by the control unit 3, in particular by a microcontroller. Furthermore, this circuit arrangement has the decoupling device 12 shown in FIG. The diode 34 of the decoupling device 12 again causes no reaction to the status signal 26 in the case of a closed contact element 13 is possible. Thus, the position of the switch 20 of the button 18 can be detected by the control device 3 in the case of an open and closed contact element 13. The voltage U _z may have the following properties: If the button 18 is not actuated, the input 22 is free of the supply alternating voltage U _v . At the output 24 is no voltage. In the non-actuated state of the button 18, the voltage U _{z is} equal to zero. In the actuated state of the button 18, however, is located at the input 22, the AC supply voltage U _v and is rectified by the diode 52. The voltage U _z thus alternates between zero and an amplitude value, which results from the selection of the resistors 27 and 31, namely for example between zero volts and five volts. The voltage U _z changes with the frequency of the supply AC voltage U _v - In such a manner, the controller 3 can reliably, clearly and quickly recognize whether the button 18 has been pressed or not. The contact element 13 can, as in the above examples, be actuated via a control part 15, not shown in FIG. 14, which is connected to the control device 3 via control lines 16 and / or 17, not shown, for controlling the control part 15.

In this modification, the power supply unit 10 is designed as a switching power supply. Therefore, a rectifier circuit 53 is provided between the contact 14 and the contact 12b. For the circuit arrangement shown in Fig. 14, other embodiments of the power supply unit 10 may be provided, then, depending on the design, the rectifier circuit 53 may be omitted.

The circuit arrangement 2 according to this modification can also be combined with all the control parts 15 described above. Fig. 9 shows an alternative embodiment of the switch 1 1 and a circuit for driving it. The switch 1 1 is also a bistable relay, such as a surge relay. The control part 15 includes a coil 47; by energizing the coil 47 with a current pulse, the switching state of the movable contact element 13 changes. The coil 47 is coupled on the one hand with the DC operating voltage U _B or another DC voltage; on the other hand, it is connected to the collector of an NPN bipolar transistor 48. The emitter of the bipolar transistor 48 is connected to the reference potential 9. Its base is connected to the control input 1 1 a of the control part 15. In this embodiment, the control input 1 1 a of the switch 1 1 via an ohmic resistor 49 and a diode 50 is coupled to the button 18, namely, for example, with that contact element of the probe 18, which is also connected to the state detection device 23. The anode of the diode 15 is coupled to the push button 18 and its cathode to the control input 1 1 a. The control input 1 1 a is also coupled via a capacitor 51 to the reference potential 9. The diode 50, the resistor 49 and the capacitor 51 are all a small capacitor power supply. These components and the connection with the button 18 ensure that the switch 1 1 is closed immediately after pressing the button 18, regardless of the control device. 3 ,

The detection of the actuation of the button 18 with a closed contact element 13 can be done with the state detection devices 23 shown in FIG. 23 or 24. Since different types of bistable relay are used in terms of their performance, additional, designed for high-power operation relay can be used and indeed parallel to the switch 1 1, an additional switch - for example, a relay - are used, via which at least one electric Consumer of the household appliance 1 is supplied with electrical energy. The activation of the additional switch can be done in an analogous manner, as the control of the switch 1 1. Such an additional switch is then preferably designed for operation with currents up to 16 amps. The control device 3 may also be a plurality of microcontrollers which communicate with each other via an internal communication bus. For example, a first microcontroller may be connected to the state detection device 23 - it can then recognize the instantaneous switching state of the button 18. A second microcontroller can be used to control the switch 1 1. The first and the second microcontroller can exchange data with each other via the communication bus. Both microcontrollers may be coupled to the power supply unit 10.

Overall, a circuit arrangement 2 is provided with which a clear recognition of the actuation of the button 18 is made possible. The control device 3 can automatically detect whether the button 18 has been actuated by an operator in the switched-on state of the domestic appliance 1 and thus the domestic appliance 1 should be switched off safely. The control device 3 can also switch off the household appliance 1 automatically after completion of an operating process. Such an automatic switch-off is also possible after failure of the supply AC voltage U _v . This can detect the control device 3, for example, based on a reduced amplitude of the DC operating voltage U _B , when selbige voltage is provided to a capacitor of the power supply unit 10. So a safe switching off the household appliance is also possible in the case of failure of the AC supply voltage U _v . By using a bistable switch 11, an already started operating process can be properly completed even after a prolonged failure of the supply alternating voltage U _v . For the electrical supply of consumers, such as a heater or a motor, or sensors of the household appliance 1, the circuit arrangements described above 2, not shown, branch points. For example, the AC supply voltage U _v between the reference potential 9 and the contact element 14 can be tapped. Furthermore, the DC operating voltage UB can also serve to supply the consumers or the sensors of the domestic appliance 1. The branching points for the consumers or sensors are preferably incorporated in the circuit arrangement 2 in such a way that opening of the contact element 13 also interrupts the electrical supply of the consumers or sensors. LIST OF REFERENCE NUMBERS

1 household appliance

2 circuit arrangement

3 control device

4 circuit input

5, 6 input connections

7 phase conductors

8 neutral conductors

9 reference potential

10 power supply unit 11 electrical switch

12 decoupling device

12a, 12b, 12c connections

13 movable contact element 14 stationary contact element 15 control part

1 1 a, 1 1 b Control inputs

16, 17 control lines

18 buttons

19 control element

20, 21 switches

22 entrance

23 state detection device 24 output

25 detection input

26 status signal

27 resistors

28 resistance

29 diode

30 diode

31 resistance

32 energy storage 33 branching unit

34 diode

35 diode

36 resistance / NTC / PTC

37, 38 coils

39 coil

40 coil

41, 42 bipolar transistors

43 coil

44, 45 switch

46 resistance

47 coil

48 bipolar transistor

49 resistance

50 diode

51 capacitor

52 diode

53 rectifier circuit

U _v AC supply voltage

U _B DC operating voltage

Uz tension

V DC voltage

Claims

claims

1 . Circuit arrangement (2) for operating a household appliance (1), with:

a circuit input (4) for applying an alternating supply voltage (U _v ),

a control device (3) for controlling operating processes of the household appliance (1),

a voltage supply unit (10) coupled to the control device (3) for providing a DC operating voltage (U _B ) for the control device (3) from the alternating supply voltage (U _v ),

an actuatable by an operator button (18), via which the power supply unit (10) with the circuit input (4) can be coupled, and

a parallel to the switch (18) connected electrical switch (1 1), which by the control device (3) between an electrically conductive switching state, in which the power supply unit (10) is coupled to the circuit input (4), and an electrically blocking switching state switchable is

characterized in that

the circuit arrangement (2) comprises a state detection means (23) coupled to the pushbutton (18) and the control device (3), which is designed to detect a switching state of the pushbutton (18) and a state signal reproducing the switching state of the pushbutton (18) (26) to the control device (3) output, wherein the control device (3) is adapted to switch the electrical switch (1 1) depending on the state signal (26) and that the circuit arrangement (2) between the electrical switch ( 1 1) and the state detection means (23) connected decoupling means (12) which is adapted to the state detection device (23) at least partially electrically from the electrical switch (1 1) to decouple.

2. Circuit arrangement (2) according to claim 1, characterized in that the state detection means (23) a rectifier, in particular a diode (52), which is connected to the probe (18) and to a voltage divider, and that the voltage divider the state signal (26) can be tapped.

3. Circuit arrangement (2) according to claim 1, characterized in that the state detection device (23) has a circuit arrangement in which between an input (22) and an output (24) of the state detection device (23) at least one resistor (27) is connected in that the output (24) is coupled via a parallel connection of a further resistor (28) and a diode (29) to a DC voltage source and wherein the output (24) via a parallel circuit of a second diode (30) and another Resistor (31) to the reference potential (9) of the circuit arrangement (2) is coupled.

4. Circuit arrangement (2) according to one of claims 1 to 3, characterized in that the decoupling device (12) has an ohmic resistance (36) and / or a first diode (34) whose cathode is connected to the electrical switch (1 1). and whose anode is coupled to the state detecting means (23).

5. Circuit arrangement (2) according to claim 4, characterized in that the decoupling device (12) has a second diode (35) whose anode with the switch (1 1) and whose cathode to the cathode of the first diode (34) and the Voltage supply unit (10) is connected.

6. Circuit arrangement (2) according to one of the preceding claims, characterized in that the state detection device (23) is adapted to the control device (3) an electrical voltage (U _z ) as a state signal (26) output, which in an open switching state of the pushbutton (18) has at least one first property and in a closed switching state of the pushbutton (18) at least one second property.

7. Circuit arrangement (2) according to one of the preceding claims, characterized in that the control device (3) is adapted to Recognizing an actuation of the button (18) based on the state signal (26) to change the switching state of the electrical switch (1 1), in particular after detecting an actuation of the button (18) in the conductive state of the electrical switch (1 1) seligen switch (1 1) in the electrically blocking switching state to switch.

8. Circuit arrangement (2) according to one of the preceding claims, characterized in that the control device (3) is designed to switch after completion of an operating process of the domestic appliance (1) the electrical switch (1 1) in the electrically blocking switching state.

9. Circuit arrangement (2) according to one of the preceding claims, characterized in that the electrical switch (1 1) is a bistable relay.

10. Circuit arrangement (2) according to claim 9, characterized in that the bistable relay has two coils (37, 38), wherein the coils (37, 38) on the one hand with a DC operating voltage U _{B of} the power supply unit (10) and on the other hand with each Are coupled to the collector of an NPN bipolar transistor (41, 42) whose respective emitter is connected to the reference potential (9) of the circuit arrangement (2), and that the respective base of the NPN

Bipolar transistors (41) via control lines (16) are coupled to the control device (3).

1 1. A circuit arrangement (2) according to claim 10, characterized in that the base of the closing of the switch (1 1) competent bipolar transistor (41) via an ohmic resistor (46) is coupled to a DC voltage source, which provides a DC voltage V. when the button (18) is pressed.

12. Circuit arrangement (2) according to claim 1 1, characterized in that the bistable relay comprises a coil (43), depending on the current direction of a

Current pulse, the switch (1 1) opens or closes and which is connected to a first switch (44) and with a second switch (45), wherein one side of the sink (43) via the first switch (44) and the other side of the Sink (43) via the second switch (45) with a DC voltage (V) or with a Reference potential (9) is connected, and that the first and the second switch (44, 45) via signal lines (16, 17) are controllable, which are connected to the control device (3).

13. Circuit arrangement (2) according to one of the preceding claims, characterized in that the circuit arrangement (2) with a control input (1 1 a, 1 1 b) of the electrical switch (1 1) coupled electrical energy storage (32) and the electrical switch (1 1) to maintain the conductive state switching with electrical energy from the energy storage device (32) can be supplied.

14. Circuit arrangement (2) according to one of the preceding claims, characterized in that a control input (1 1 a, 1 1 b) of the electrical switch (1 1) coupled to the power supply unit (10) and / or with the button (18) is, so that upon actuation of the button (18) by the operator of the electrical switch (1 1) is switchable from the electrically blocking in the electrically conductive switching state.

15. Domestic appliance (1) with a circuit arrangement (2) according to one of the preceding claims.

16. A method for operating a domestic appliance (1) with a circuit arrangement (2), wherein operating processes of the domestic appliance (1) are controlled by a control device (3), comprising the steps:

- Applying an AC supply voltage (U _v ) to a

Circuit input (4) of the circuit arrangement (2),

Coupling a voltage supply unit (10) coupled to the control device (3) to the circuit input (4) via a pushbutton (18),

- Providing a DC operating voltage (U _B ) for the control device

(3) from the AC supply voltage (U _v ) by the power supply unit (10), and

Switching an electrical switch (1 1) connected in parallel with the pushbutton (18) between an electrically conductive switching state in which the Voltage supply unit (10) is coupled to the circuit input (4), and an electrically blocking switching state by the control device (3),

characterized in that

a switching state of the pushbutton (18) is detected by means of a state detection device (23) coupled to the pushbutton (18) and the control device (3) in such a way that a state signal (26) reproducing the switching state of the pushbutton (18) is output to the control device (3) wherein the control device (3) switches the electrical switch (11) as a function of the status signal (26), and that the state detection device (23) is disconnected by means of a decoupling device (11) connected between the electrical switch (11) and the state detection device (23). 12) is at least partially electrically decoupled from the electrical switch (1 1).