WO2009121814A1

WO2009121814A1 - Circuit arrangement for operating at least two electric loads of a household appliance and corresponding method

Info

Publication number: WO2009121814A1
Application number: PCT/EP2009/053690
Authority: WO
Inventors: Guido Sattler; Hasan Gökcer ALBAYRAK
Original assignee: BSH Bosch und Siemens Hausgeräte GmbH
Priority date: 2008-03-31
Filing date: 2009-03-27
Publication date: 2009-10-08
Also published as: DE102008016475A1

Abstract

The invention relates to a circuit arrangement (1) for operating at least two electric loads (2, 2a, 2b, 2c,..., 2n) of a household appliance, wherein the at least two electric loads (2, 2a, 2b, 2c,..., 2n) are connected in series each with a separate switch (3, 3a, 3b, 3c,..., 3n) and are coupled to a connection (8) of an input (5) of the circuit arrangement (1) by way of a common terminal (6), and wherein a control and/or regulating unit (11) is designed to actuate the respective separate switches (3, 3a, 3b, 3c,..., 3n), wherein a current detection device (13) is coupled to the control and/or regulating unit (11), said detection device being designed to detect a total current flowing through a power line (7) coupling the common terminal (6) to the connection (8). The invention further relates to a corresponding method.

Description

Circuit arrangement for operating at least two electrical loads of a household appliance and corresponding method

The present invention relates to a circuit arrangement for operating at least two electrical loads of a domestic appliance, in which the at least two electrical loads each connected in series with a separate switch and coupled via a common pole to a terminal of an input of the circuit arrangement, and in which a Control and / or regulating unit is designed for driving the respective one separate switch. The present invention further relates to a corresponding method for operating at least two electrical consumers of a domestic appliance.

Circuit arrangements for operating at least two electrical consumers, and in particular for operating a plurality of electrical consumers, one

Domestic appliance are already known from the prior art. In a known, derived from the applicant circuit arrangement for operating a plurality of electrical loads, such as an electric motor, a heater and / or a pump, the electrical loads each have a separate switch assigned, via which the electrical loads are put into operation can. The electrical consumers are each with a separate

Switch connected in series, each with a separate switch from one side

Control and / or regulating unit can be controlled. In the known

Circuit arrangement, the at least two electrical loads are coupled via a common pole to a terminal of an input of the circuit arrangement.

In the present case, interest is directed to monitoring switching operations of the switches assigned to the at least two electrical consumers or monitoring proper operation of the switches and / or the electrical consumers. It is an object of the present invention to provide a circuit arrangement and a method for operating at least two electrical loads of a domestic appliance, in which and in which with little technical effort monitoring the proper operation of the electrical load and / or the switch is guaranteed.

This object is achieved by a circuit arrangement and by a method having the features of the respective independent claim. Advantageous embodiments and embodiments of the invention are specified in the dependent claims.

In a circuit arrangement according to the invention for operating at least two electrical consumers of a domestic appliance, the at least two electrical consumers are each connected in series with a separate switch and coupled via a common pole to a terminal of an input of the circuit arrangement. In the circuit arrangement, a control and / or regulating unit is designed for driving the respectively one separate switch. An idea of the invention is that a current detection device is coupled to the control and / or regulating unit, which is designed to detect a summation current which flows via a current line coupling the common pole to the connection.

In other words, the present invention is based on the recognition that for monitoring a proper operation of the electrical loads and / or the respective separate switch, a current detection device can be used, which is coupled to the control and / or regulating unit and which for detecting a is formed over a the common pole to the terminal coupling power line flowing sum current. In this way, it is advantageously achieved that the proper function of the electrical consumers and / or the respectively one separate switch can be ascertained on the basis of the detected summation current. The term "domestic appliance" is understood here in particular as a domestic appliance for the care of laundry items, such as preferably a washing machine, a dryer or a washer-dryer.

It has proved to be advantageous that the current detection device is designed for inductive current detection. Thus, in particular, the current detection device can have an induction coil in which current is induced as a function of the total current flowing via the current line coupling the common pole to the connection. Alternatively it can be provided that the current detection device comprises a Hall sensor. In order to provide a cost-reduced circuit arrangement, it can be provided in another alternative embodiment that the current detection device has a current detection resistor (shunt resistor), and the total current is detected by measuring a voltage drop across the current detection resistor.

Preferably, the control and / or regulating unit is designed to control the respective separate switch for the simultaneous monitoring of a proper operation of the at least two electrical loads and to evaluate the total current. In particular, the activation of the respectively one separate switch or the simultaneous monitoring of the proper operation of the at least two electrical consumers takes place before the electrical consumers are put into operation. In this embodiment, it is preferably provided that the control and / or regulating unit is designed to monitor the proper operation of the electrical loads in groups. In other words, the control and / or regulating unit may be capable of simultaneously monitoring a predetermined group of the electrical consumers or the switches associated with the predetermined group of electrical consumers. Furthermore, it can be provided that by controlling a single switch, the proper function of the individual switch and / or a single electrical load is checked.

It has proven to be advantageous that a desired current characteristic is stored in the control and / or regulating unit, and the control and / or regulating unit is designed to compare the detected total current with the desired characteristic. In particular, summation current setpoints may be in the control and / or regulation unit be stored, and the detected total current can be compared with the stored summation current setpoints. In particular, it is provided in this embodiment that the summation current setpoint values are defined as a function of switching states of the switches, wherein the switch can be closed by comparing the summation current with the stored summation current setpoint values to the current switching state.

In a preferred embodiment, it is provided that admissible total current value ranges or permissible windows for the total current are predefined, and the control and / or regulating unit is designed to adopt a safe operating state when a faulty operation of a switch and / or an electrical load is detected , The safe state can be, for example, an opening of all switches and / or opening of a common switch for all electrical consumers. Furthermore, it can be provided that when an erroneous operation of a switch and / or an electrical consumer is detected, an error message is output for a user of the domestic appliance.

Preferably, the control and / or regulating unit is designed to evaluate a DC component of the total current. This embodiment is particularly advantageous when operated with direct current. Even when operating with alternating current, the evaluation of the direct current component of the summation current or the detection of a direct current component in an alternating current curve can be used to conclude a faulty operation or a malfunction of an electrical load. As a result, a safe operation of the electrical consumers is achieved.

In a preferred manner, the control and / or regulating unit is designed to evaluate a phase position of the total current. In particular with regard to the operation of an electric motor, the evaluation of the phase position of the summation current ensures that faulty operation of the electric motor can be detected. Thus, a load of an electric motor is not only a function of the current, but is also dependent on the phase angle of the current. By evaluating the phase position of the total current thus an invalid load on the electric motor can be detected. Preferably, the control and / or regulating unit is designed to evaluate an alternating current component of the total current. In particular, in the case of operation with alternating current, faulty operation can be detected by the evaluation of the alternating current component or by the detection of a current intensity or a current amplitude of the summation current of a defective operation of a switch and / or an electrical consumer.

Preferably, each of a separate switch as an electronic switching unit, in particular as a triac, is formed. In this embodiment it can be provided that the respective one, designed as an electronic switching unit separate switch as a bipolar transistor with an insulated gate electrode (IGBT, "Insulated Gate Bipolar Transistor") is formed by use of an electronic switching unit, such as a triac or a bipolar transistor In addition, the electronic switching units are characterized by relatively high blocking voltage as well as by high robustness and reliability.In particular, it can be provided that the one, designed as an electronic switching unit separate switch one If the switch is actuated by the control and / or regulating unit via the control connection or is located at the control connection, the control connection is provided via which the switch can be actuated by the control and / or regulating unit an electrical voltage, so the associated electrical load can be put into operation.

The respective one separate switch may alternatively be designed as an electromechanical switching unit, in particular as a relay. As an electromechanical switching unit and contactors can be used. By using electromechanical switching units a cost-reduced circuit arrangement is created. In this embodiment, it can be provided, in particular, that the separate switch formed as an electromechanical switching unit comprises a switching element and a control element, wherein the switching element can be changed in its switching state by energizing the control element controlled by the control and / or regulating unit. In particular, the switching element is connected in series with the associated electrical load. Thus, if the control of the control and / or regulating unit controlled or energized, so can the electrical loads are put into operation via the switching element or turned off.

Preferably, the at least two electrical consumers comprise an electric motor and / or a pump and / or a heater and / or a fan and / or a light source for illuminating a drum interior of the domestic appliance. In one embodiment, it is preferably provided that the control and / or regulating unit is designed to monitor the proper operation of the heater and / or a switch associated with the heater as well as the proper operation of the fan and / or a switch associated with the fan. In particular, for this purpose, the total current flowing via the heater and the fan is detected by means of the current detection device and further evaluated by means of the control and / or regulating unit. In this case, for example, the current intensity and / or the phase position of the summation current can be evaluated and compared with stored summation current setpoint values. The summation current setpoints can be predefined for the considered combination of the electrical consumers, for the heating and for the fan. If, for example, a predefined window or a predetermined permissible sum-value setpoint range is exceeded, this indicates, in particular, a malfunction of the electrical consumers and / or the associated switches. In this case, the control and / or regulating unit preferably assumes a safe operating state in which the electrical consumers are decoupled from a supply network by opening all associated switches. In addition, an error message can be output to a user of the domestic appliance.

In a preferred embodiment, it is provided that the at least two electrical consumers are coupled to the terminal of the input via a common switch arranged on the power line. The common switch can be formed in a preferred manner as an electronic switching unit, in particular as a triac, wherein alternatively it can be provided that the common switch is designed as an electromechanical switch unit, in particular as a relay. In particular, the common switch on the part of the control and / or regulating unit can be controlled so that it is achieved that the at least two electrical loads from the side of the control and / or regulating unit in a simple and reliable manner from the input of the circuit arrangement by driving only the common Switch can be decoupled. In particular, in the event that a malfunction of the electrical load and / or a switch is detected, by opening the common switch a safe operating condition can be taken by the control and / or regulating unit.

In an advantageous embodiment, it is provided that the current detection device is designed to pre-process the summation current to be evaluated. Alternatively, the pre-processing can be carried out by means of the control and / or regulating unit. In a further alternative embodiment, it is provided that the circuit arrangement comprises a current transformer, which is arranged between the current detection device and the control and / or regulating unit, and which is designed for pre-processing of the summation current to be evaluated. This ensures that the evaluated summation current can be converted in a suitable form and evaluated by the control and / or regulating unit.

A method according to the invention is designed for operating at least two electrical consumers of a domestic appliance with the aid of a circuit arrangement. In this case, the at least two electrical consumers are each connected in series with a separate switch and coupled via a common pole to a terminal of an input of the circuit arrangement. In the method, the respective one separate switch is controlled by means of a control and / or regulating unit. A basic idea in the method according to the invention is that a summation current flowing via a current line coupling the common pole to the connection is detected by means of a current detection device coupled to the control and / or regulating unit.

In the method, a DC component of the total current is preferably evaluated by means of the control and / or regulating unit.

In particular, a phase position of the mute current is evaluated by means of the control and / or regulating unit. Preferably, an alternating current component of the total current is evaluated by means of the control and / or regulating unit.

In the method, the respective separate switch is preferably activated for the simultaneous monitoring of a proper operation of the at least two electrical consumers and the summation current is evaluated.

In particular, in the method, a desired current characteristic is predetermined, wherein the total current is compared with the desired characteristic by means of the control and / or regulating unit.

Advantageous embodiments of the circuit arrangement according to the invention are to be regarded as advantageous embodiments of the method according to the invention.

Further advantages, features and details of the invention will become apparent from the following description of individual preferred embodiments and with reference to the drawings. Showing:

1 shows a circuit arrangement for operating a group of electrical consumers of a domestic appliance according to an embodiment of the present invention.

Fig. 2 shows a circuit arrangement for operating a group of electrical

Consumers of a household appliance according to a second embodiment of the present invention;

Fig. 3 shows a circuit arrangement for operating a group of electrical

Consumers of a household appliance according to a third embodiment of the present invention.

The embodiments described in more detail below represent preferred embodiments of the invention. The invention is not limited to the exemplary embodiments illustrated in the drawings. All described below and in The features illustrated in the drawings can be combined with each other in a variety of ways.

In the figures, the same or functionally identical elements are provided with the same reference numerals.

A circuit arrangement 1 according to a first embodiment is shown in FIG. The circuit arrangement 1 is for operating a plurality of electrical

Consumers 2, 2a, 2b, 2c 2n formed a domestic appliance. In the present example, the domestic appliance is a domestic appliance for the care of laundry items, such as a washing machine, a dryer or a washer-dryer. The majority of electrical

Consumers 2, 2a, 2b, 2c 2n here comprise a first electric motor 2, which in the example is designed to drive a drum of the domestic appliance, a second electric motor 2a, a first and a second heater 2b, 2c, and a light source 2n Illumination of a drum interior of the household appliance. The electrical consumers 2, 2a, 2b, 2c 2n are each provided with a separate switch 3,

3a, 3b, 3c 3n connected in series and in the example on each one separate

Switch 3, 3a, 3b, 3c 3n with a first terminal 4 of an input 5 of

Circuit arrangement 1 can be coupled. In this case, the circuit arrangement 1 via the input 5 to a supply network, in particular with a supply voltage of 230 V, are connected.

The electrical consumers 2, 2a, 2b, 2c 2n are coupled via a common pole 6 and a power line 7 to a second terminal 8 of the input 5 of the circuit arrangement 1. In this case, a common switch 9 is provided on the power line 7, by means of which the electrical load from the second terminal 8 of the input 5 can be decoupled together.

The separate switches 3, 3a, 3b, 3c and 3n common switch 9 are formed in the present example as a relay. The separate switches 3, 3a, 3b, 3c 3n are each assigned a control element 10, 10a,... 10n, via which the separate

Switch 3, 3a, 3b, 3c 3n are changeable in their switching states. These are the

Control elements 10, 10a 10n coupled to a control and / or regulating unit 1 1 and controlled by this. The control and / or regulating unit 11 is formed, the Switching states of the separate switches 3, 3a, 3b, 3c 3n by an energizing or by a current application of the associated control element 10, 10a 10n to change.

Further, the common switch 9, which is formed in the present example as a relay, associated with a control element 12, by means of which the common

Switch 9 is changeable in its switching state. For this purpose, the control element 12 is coupled to the control and / or regulating unit 11 and can be controlled by it. One

Bestromen or a current application of the control 12 from the side of the

Control and / or regulating unit 1 1 causes a switching of the common switch 9.

In the present case, the interest is directed to the supervision of a proper

Operating both the electrical loads 2, 2a, 2b, 2c 2n, as well as the separate

Switch 3, 3a, 3b, 3c 3n with regard to a safe operation of the domestic appliance. For this purpose, the circuit arrangement 1 comprises a current detection device 13, which is designed to detect a current flowing through the power line 7 total current. For this purpose, the current detection device 13 in the present example comprises an induction coil 14 in which a current characterizing the current flowing through the current line 7 can be induced. This inductive current detection allows a simple yet accurate detection and evaluation of the current flowing through the power line 7 total current. The current detection device 13 also has a current transformer 15, which is designed for pre-processing of the detected total current. The current detection device 13 is connected to a current detection input 16 of the control and / or regulating unit 1 1, whereby a transmission of the detected total flow to the control and / or regulating unit 1 1 and a further evaluation of the total current are possible.

The operation of the circuit arrangement 1 will be explained in more detail below. The aim is already before a start-up of the electrical load 2, 2a, 2b, 2c 2n, as well as during operation, a malfunction of the electrical load 2, 2a, 2b,

2c 2n and the separate switch 3, 3a, 3b, 3c 3n to recognize or a

Monitoring the electrical loads 2, 2a, 2b, 2c 2n and the separate

Switch 3, 3a, 3b, 3c 3n to allow. Moreover, it is the goal of the current ones Operating conditions of the separate switches 3, 3a, 3b, 3c 3n and the electrical

Consumers 2, 2a, 2b, 2c 2n determine or capture. For this purpose, in the control and / or regulating unit 11 summation current setpoint values or a setpoint characteristic of the

Subtotal stored, wherein the control and / or regulating unit 1 1 is formed to compare the detected sum current, in particular its current strength and its phase position with the stored summation current setpoints. Thus, it can be closed directly on the current operating state of the individual electrical loads 2, 2a, 2b, 2c 2n and the separate switch 3, 3a, 3b, 3c 3n.

In the present example it is provided that the electrical consumers 2, 2a, 2b, 2c, ..., 2n and the separate switches 3, 3a, 3b, 3c 3n are monitored in groups.

For example, it can be provided that for checking a proper operation of the first and the second motor 2, 2a and the associated switches 3, 3a, the control and / or regulating unit 11 controls the associated switches 3, 3a. In this case, the remaining separate switches 3b, 3c 3n remain in their open states. Thus, flows over the power line 7, a total current, which is a sum of the currents flowing through the first and the second electric motor 2, 2a currents. The corresponding summation current setpoint values, which are to be compared with the detected summation current, are stored accordingly in the control and / or regulating unit 11. Thus, for example, it can be directly recognized that the first and the second electric motors 2, 2 a are in operation. If the detected summation current, for example the current intensity and / or a phase position, differs from the stored summation current desired values, this indicates a malfunction. In this case, the control and / or regulating unit 1 1 is designed to assume a safe operating state. In the present example, the control and / or regulating unit 1 1 for opening all separate switches 3, 3a, 3b, 3c 3n and to open the common

Switch 9 is formed to assume the safe operating condition. This ensures that the electrical consumers 2, 2a, 2b, 2c 2n on both sides of

Supply network remain decoupled.

Furthermore, it is provided, for example, that the first and the second heater 2b, 2c and the associated separate switches 3b, 3c are monitored simultaneously. If the two of the first and the second heater 2b, 2c associated separate switch 3b, 3c closed by the control and / or regulating unit 11, so flows over the first and second heaters 2b, 2c power. The summation current, which in the present case represents a sum of the currents flowing via the first and the second heater 2b, 2c, can now be detected by the current detection device 13, transmitted to the control and / or regulating unit 11 and by means of the control and / or regulating unit 11 are evaluated. In order to detect a malfunction of the first and / or the second heater 2b, 2c and / or the associated separate switches 3b, 3c or to monitor the proper operation, in the control and / or regulating unit 11, the summation current desired values for this combination the currents, ie for the sum of the currents flowing through the first and the second heater 2b and 2c, stored. When checking the first and the second heater 2b, 2c is also provided that a fan (not shown) is turned on as an electrical consumer with. Accordingly, in the control and / or regulating unit 1 1, the summation current setpoints are stored, which correspond to a summation current, which represents a sum of the currents flowing through the first and the second heater 2b, 2c and beyond the fan. If now a malfunction of the first and / or the second heater 2b, 2c and / or the fan and / or the associated separate switch 3b, 3c detected, so the control and / or regulating unit 11 assumes the safe operating state, in which both the separate switches 3b, 3c, as well as the common switch 9 remain in their open switching states.

A circuit arrangement 1 for operating at least two electrical consumers of a domestic appliance according to a second exemplary embodiment is reproduced in FIG. The circuit arrangement 1 according to the second embodiment essentially corresponds to the circuit arrangement 1 according to the first exemplary embodiment. In the present case, the differences between the exemplary embodiments will be discussed. The circuit arrangement 1 according to the second embodiment comprises a further group of separate switches 17, 17a, 17b,

..., 17n, which are associated with the electrical loads 2, 2a, 2b, 2c 2n in addition to the separate switches 3, 3a, 3b, 3c 3n. So are the electric ones

Consumer 2, 2a, 2b, 2c 2n via the other separate switches 17, 17a, 17b 17n and further coupled via the common pole 6 to the second terminal 8 of the input 5 of the circuit arrangement 1. Here, the first and the second heater 2b, 2c are summarized and have a common pole 18, via which the first and the second heater 2b, 2c with the other separate switch 17b, which is presently provided in common for the first and the second heater 2b, 2c, are coupled.

The further group of separate switches 17, 17a, 17b 17n have in the second

Embodiment, the task of the common switch 9 according to the first embodiment. Thus, the electrical loads 2, 2a, 2b, 2c 2n can be decoupled from both sides of the input 5 and thus from the supply network with regard to a safe operation of the domestic appliance. Also in the circuit arrangement 1 according to the second embodiment, individual electrical consumers 2, 2a, 2b, 2c 2n as well as grouped into electrical consumers 2, 2a, 2b, 2c 2n and correspondingly the associated separate switches 3, 3a, 3b, 3c 3n and 17, 17a, 17b 17n are monitored by means of the current detection device 13.

The circuit arrangement 1 according to the second embodiment accordingly comprises a further group of control elements 19,... 19n, which are assigned to the further separate switches 17, 17a, 17b..., 17n. The other controls

19 19n are coupled to the control and / or regulating unit 11 and controlled by this. If the other control elements 19 19n are energized by the control and / or regulating unit 1 1, the other separate switches 17, 17 a, 17 b 17 n are changed in their switching states. In the present case, it should be mentioned that the further separate switches 17, 17 a, 17 b 17 n with the corresponding

Control elements 19, ... 19n are designed as relays.

A circuit arrangement 1 according to a third embodiment is shown in FIG. The circuit arrangement 1 according to the third embodiment is designed to operate at least two electrical consumers 2, 2a, 2b, 2c,... 2n of a domestic appliance and essentially corresponds to the circuit arrangement 1 according to the first exemplary embodiment, so that the differences are discussed in detail here becomes. The circuit arrangement 1 according to the third exemplary embodiment comprises a switch 20 common to the control elements 10, 10a, which in the present case has a common disconnection path for the control elements 10, 10a and 10n and thus for the separate switches 3, 3a, 3b, 3c and 3n electrical load 2, 2a, 2b, 2c 2n represents. Accordingly, the

Circuit arrangement 1, an additional control element associated with the switch 20 21, which is coupled to the control and / or regulating unit 1 1 and controlled by this. Thus, the control and / or regulating unit 11 is able, by a current application of the additional control element 21 for the controls

10, 10a 10n common switch 20 to change in its switching state. For example, if a malfunction of the electrical load 2, 2a, 2b, 2c 2n and / or the separate switch 3, 3a, 3b, 3c 3n detected, the switch 20 is switched by a current application of the additional control element 21 in its open switching state, which the safe operating state of the control and / or regulating unit 11 corresponds.

Claims

claims

1. Circuit arrangement (1) for operating at least two electrical

Consumers (2, 2a, 2b, 2c 2n) of a domestic appliance, in which the at least two electrical consumers (2, 2a, 2b, 2c 2n) each with a separate

Switch (3, 3a, 3b, 3c 3n) connected in series and via a common

Pol (6) to a terminal (8) of an input (5) of the circuit arrangement (1) are coupled, and wherein a control and / or regulating unit (1 1) for driving the respective one separate switch (3, 3a, 3b , 3c 3n), characterized in that a current detection device (13) with the

Control and / or regulating unit (1 1) is coupled, which is designed for detecting a via the the common pole (6) to the terminal (8) coupling power line (7) flowing sum flow.

2. Circuit arrangement (1) according to claim 1, characterized in that the

Control and / or regulating unit (1 1) is formed, each a separate

Switch (3, 3a, 3b, 3c 3n) for simultaneously monitoring a proper operation of the at least two electrical loads (2, 2a, 2b, 2c 2n) to control and evaluate the total current.

3. Circuit arrangement (1) according to claim 1 or 2, characterized in that a desired current characteristic in the control and / or regulating unit (1 1) is stored, and the control and / or regulating unit (1 1) for comparing the detected summed current is formed with the desired current characteristic.

4. Circuit arrangement (1) according to one of the preceding claims, characterized in that the control and / or regulating unit (1 1) is designed for evaluating a DC component of the total current.

5. Circuit arrangement (1) according to one of the preceding claims, characterized in that the control and / or regulating unit (1 1) is designed for evaluating a phase position of the summation current.

6. Circuit arrangement (1) according to one of the preceding claims, characterized in that the control and / or regulating unit (1 1) is designed for evaluating an alternating current component of the total current.

7. Circuit arrangement (1) according to one of the preceding claims, characterized in that each of a separate switch (3, 3a, 3b, 3c 3n) as an electronic switching unit, in particular as a triac, is formed.

8. Circuit arrangement (1) according to one of the preceding claims, characterized in that each of a separate switch (3, 3a, 3b, 3c 3n) is designed as an electromechanical switching unit, in particular as a relay.

9. Circuit arrangement (1) according to one of the preceding claims, characterized in that the at least two electrical consumers (2, 2a, 2b, 2c 2n) comprise an electric motor (2, 2a).

10. Circuit arrangement (1) according to one of the preceding claims, characterized in that the at least two electrical consumers (2, 2a, 2b, 2c 2n) comprise a pump.

1 1. Circuit arrangement (1) according to one of the preceding claims, characterized in that the at least two electrical consumers (2, 2a, 2b, 2c 2n) comprise a heater (2b, 2c).

12. Circuit arrangement (1) according to one of the preceding claims, characterized in that the at least two electrical consumers (2, 2a, 2b,

2c 2n) via a on the power line (7) arranged common

Switch (9) to the terminal (8) of the input (5) are coupled.

13. Circuit arrangement (1) according to claim 12, characterized in that the common switch (9) as an electronic switching unit, in particular as a triac, is formed.

14. Circuit arrangement (1) according to claim 12, characterized in that the common switch (9) is designed as an electromechanical switching unit, in particular as a relay.

15. A method for operating at least two electrical consumers (2, 2a, 2b, 2c 2n) of a domestic appliance with a circuit arrangement (1), wherein the at least two electrical loads (2, 2a, 2b, 2c 2n), each with a separate Switch (3, 3a, 3b, 3c 3n) connected in series and coupled via a common pole (6) to a terminal (8) of an input (5) of the circuit arrangement (1), and each having a separate switch (3, 3a, 3b, 3c 3n) is controlled by means of a control and / or regulating unit (1 1), characterized in that a summation current flowing via a common line (6) to the connection (8) coupling current line (7) by means of a with the control and / or regulating unit (1 1) coupled current detection device (13) is detected.

16. The method according to claim 15, characterized in that a DC component of the summation current by means of the control and / or regulating unit (1 1) is evaluated.

17. The method according to claim 15 or 16, characterized in that a

Phase position of the summation current by means of the control and / or regulating unit (1 1) is evaluated.

18. The method according to any one of claims 15 to 17, characterized in that an alternating current component of the summation current by means of the control and / or

Control unit (1 1) is evaluated.

19. The method according to any one of claims 15 to 18, characterized in that a desired current characteristic is specified, and the sum current with the desired current characteristic by means of the control and / or regulating unit (1 1) is compared.

20. The method according to any one of claims 15 to 19, characterized in that the respective one separate switch (3, 3a, 3b, 3c 3n) for simultaneous

Monitor proper operation of the at least two electrical

Consumer (2, 2a, 2b, 2c 2n) controlled and the total current is evaluated.