EP2044683A1

EP2044683A1 - Control for electrically adjustable furniture

Info

Publication number: EP2044683A1
Application number: EP07787641A
Authority: EP
Inventors: Walter Koch
Original assignee: Logicdata Electronic and Software Entwicklungs GmbH
Current assignee: Logicdata Electronic and Software Entwicklungs GmbH
Priority date: 2006-07-20
Filing date: 2007-07-17
Publication date: 2009-04-08
Also published as: WO2008009679A1; US8072181B2; US20090185403A1; AU2007275167A1; CA2657889A1; DE102006033712A1

Abstract

The invention relates to a control for electrically adjustable furniture, comprising a mains voltage region (1) and a low voltage region (2), which are electrically separated. A rectifying power supply (10), arranged in the mains power region (1), generates a rectified voltage applied to supply terminals (11) from a mains alternating voltage. The rectified voltage at the supply terminals (11) may be supplied to a first motor connection (20), arranged in the mains voltage region (1), depending on a first control signal (MS1). The control further comprises a first control device (30), arranged in the mains voltage region (1), an operating connection (32) and a first control output (31), for providing the first control signal (MS1). An operating device (40), arranged in the low voltage region (2) is connected to the operating connection (32) by means of an electrically insulating coupling (50).

Description

description

Control for electrically adjustable furniture

The invention relates to a control for electrically adjustable furniture and a use of the controller

At present, many tables are offered, especially desks with tabletops, in which the height of the tabletop is adjustable via a special drive. Even beds, such as comfort beds or hospital beds, can be adjusted by electrical drives approximately in height or tilt angle of the bed.

It is possible to use DC motors for the drive, which are operated with a low voltage of about 12 V to 24 V. For this purpose, the mains voltage, usually in Europe at about 230 V lying, reduced via a transformer in the lower voltage range of the DC motors and converted via a rectifier circuit into a DC voltage. The motors can be controlled by a controlled connection of the motors with the low DC voltage. For this purpose, a control board coupled with operating elements can be used, which can be arranged, for example, together with the transformer and the rectifier circuit. However, for this type of control, it is necessary to provide one or more transformers, which are to be dimensioned correspondingly large because of the high power consumption of the electric motors and therefore represent a non-negligible cost factor for the production of such a control. Another possibility for a drive with electrically adjustable furniture is the use of AC motors that can be operated with the mains AC voltage. The AC motors are not regulated and only the supply voltage from the AC mains is switched through. This eliminates the possibility of regulating the drive. This is particularly problematic when multiple motors are to be controlled simultaneously and synchronized.

It is therefore an object of the invention to provide a controller for electrically adjustable furniture that can be produced inexpensively and with little effort and yet allows precise control of engines. It is a further object of the invention to provide a use for the controller.

These objects are achieved with the subject matters of the independent claims. Embodiments and developments of the invention are the subject of the dependent claims.

In an exemplary embodiment of the invention, an electrically adjustable furniture control includes a mains voltage range and a low voltage range that are galvanically isolated. A rectifying supply device, which is arranged in the mains voltage range, is used for

Generation of a voltage applied to supply terminals rectified voltage from an AC line voltage. At a first motor terminal, which is likewise arranged in the mains voltage range, the rectified voltage applied to the supply terminals can be output as a function of a first control signal. A first control device has an operating connection and a first control output for outputting the first control signal. The first tax The generating device is arranged in the mains voltage range. An operating device arranged in the low voltage range is connected to the operating connection of the first control device via a galvanically separating coupling.

By separating the controller into a mains voltage range and a low voltage range, it can be achieved that the operating device, which is accessible, for example, to a human user, can be operated at a voltage that is not dangerous for people and lies in the range of a few volts. This prevents the user with the higher voltage in the mains voltage range, which results in Europe, for example, from the approximately 230 volts and in North America from the approximately 115 volts of the respective mains AC voltage comes into contact and thus experiences an electric shock.

At the same time, the provision of the DC voltage at the supply terminals of the supply means enables precise control of a voltage delivered to a DC motor. In addition, it is possible to dispense with the use of a transformer designed for high power, since the supply device directly converts the AC mains voltage provided by an AC power supply network into the DC voltage or generates the DC voltage directly from the AC mains voltage.

In various embodiments of the invention, conventional rectifiers with rectifier diodes or controlled transistor bridges may be used for the rectifying supply device. - A -

In other embodiments of the invention, for example, additional sensors may be provided for detecting various states of a motor connected to the motor terminal, such as a motor current or an engine speed. This allows even more precise control or regulation of the connected motor.

The controller can also provide additional motor connections for other motors that can be controlled or controlled independently via the control unit.

Since strong electrical fields can occur at the high voltages in the mains voltage range, in particular the DC voltages of the controller, it is possible to provide shielding of the electrical fields for lines in the mains voltage range, which carry the high voltage, a shield, for example, as a foil shield with metallic foil or with a metallic network mesh is executed. When the controller is mounted in a housing, such as a plastic housing, a metal foil or plate connected to a reference potential terminal, such as a common ground terminal, may also be attached to at least one side of the housing, such as the interior of the housing Housing be attached to the top.

A controller according to the invention can be used for example in an electrically height-adjustable table, such as a desk or a workbench. Furthermore, a control according to the invention can also be used with electrically adjustable beds, such as in comfort beds or beds in the hospital or care sector. The invention will be explained in more detail below with reference to several embodiments with reference to FIGS. Functionally or functionally identical elements bear the same reference numerals.

Show it:

1 shows a first embodiment of a controller according to the invention,

2 shows a second embodiment of a controller according to the invention,

FIG. 3 shows a third exemplary embodiment of a controller according to the invention,

FIG. 4 shows a fourth exemplary embodiment of a controller according to the invention,

5 shows a fifth embodiment of a controller according to the invention,

6 shows a sixth embodiment of a controller according to the invention and

Figure 7 shows a seventh embodiment of a controller according to the invention.

Figure 1 shows an exemplary embodiment of an inventive control for electrically adjustable furniture. In this case, a rectifying supply device 10 is provided with four diodes D connected for a full-wave rectification and a smoothing capacitor C. The rectifier ter 10 is coupled on the input side with network connections 12. A motor terminal 20 is connected to one pole directly and to the other pole via a transistor 23 to supply terminals 11 of the rectifier 10. The negative pole of the supply terminals 11 is connected to a reference potential terminal GND.

A first control device 30 has a first control output 31 via which a first control signal MS1 can be delivered to the control terminal of the transistor 23. At the motor terminal 20, an electric motor 60 is connected, which is preferably designed as a DC motor. The rectifier 10, the first motor terminal 20 and the first control device 30 are arranged in a mains voltage range 1, which is designed for voltages in the range of about 100 to 400 volts.

An operating device 40, which is arranged in a low-voltage region 2, is connected to an operating connection 32 of the control device 30 via a galvanically separating coupling 50. The galvanically separating coupling 50 can be designed, for example, as an optocoupler but also as an infrared connection or radio connection. The galvanically separating coupling 50 is arranged in the illustrated embodiment in the mains voltage range 1. However, it can also be provided at one point between mains voltage range 1 and low voltage range 2. It should only be ensured that the extra-low voltage range 2 does not come into galvanic contact with the higher voltages of the mains voltage range 1.

The operating device 40 has a sensor means 41, via which a user can transmit control commands. The first te sensor means 41 is executed in this embodiment as a simple switch or pushbutton, but can be replaced by other sensors, without departing from the scope of the invention.

About the power terminals 12 of the controller or the rectifier 10 is a mains AC voltage, for example, fed from a conventional AC power supply. The rectifier 10 converts the mains AC voltage into a rectified and smoothed DC voltage and makes it available at the supply terminals 11. The full-wave rectification, which is embodied here as a bridge rectifier, can also be replaced by other rectifier circuits, for example, center rectifier or low-consumption half-wave rectifier.

The first control device 30 is set up to generate a first control signal MS1 for controlling the transistor 23 as a function of signals at the operating terminal 32, which are transmitted by the operating device 40. For example, the control device 30 generates a pulse-width-modulated signal which opens the transistor 23 periodically. As a result, a DC voltage which depends on the DC voltage provided at the supply terminals 11 and the pulse duty factor of the pulse-width-modulated control signal MS1 is applied to the motor terminal 20 on average over time. This leads to a rotation of the motor or a movement of the drive for an electrically adjustable piece of furniture.

The control shown thus offers both the possibility of exact control of an electric motor and a protection of a user from a dangerous voltage from the mains voltage range 1. In addition, can be dispensed with a designed for high power transformer for powering the motor.

FIG. 2 shows a further exemplary embodiment of a control according to the invention, in which the rectifying supply device 10 comprises a transistor bridge with transistors T1, T2, T3, T4. A first path with the transistors Tl, T3 and a second path with the transistors T2, T4 are connected between the mains terminals 12 for supplying the AC line voltage. The control terminals of the transistors Tl, T2, T3, T4 are coupled to a first control output 31 of the first control device 30. Connection nodes of each two series-connected transistors Tl, T2, T3, T4 form the supply terminals 11 of the rectified voltage. Furthermore, the supply device 10 comprises an AC voltage sensor 14, which is coupled to an AC voltage sensor input 38 of the first control device 30.

As a result of a mutual activation of the transistors T 1, T 2 or of the transistors T 3, T 4, the AC line voltage is output as a rectified, unipolar voltage at the supply terminals 11 or the motor terminal 20. In order to make this synchronous to the phase position of the mains AC voltage, the phase position can be detected via the AC voltage sensor 14. For example, the transistors Tl, T2 are driven during a positive half cycle and the transistors T3, T4 during a negative half cycle. In order to change the polarity of the voltage at the motor terminal 20 and thus the direction of rotation of the motor, the drive is reversed, so that the transistors T3, T4 during a positive half cycle and the transistors Tl, T2 are driven during a negative half cycle. A current path for the current via the motor terminal 20 is thus formed alternately by the transistors Tl, T2 and the transistors T3, T4.

The activation can also be carried out only during a section of a half-wave in order to set the effective voltage at the motor connection.

In one embodiment of the embodiment, a smoothing capacitor C is connected between the supply terminals 11.

FIG. 3 shows a further exemplary embodiment of a controller according to the invention. In this case, in addition to the first motor terminal 20, a second motor terminal 20a is provided which serves to supply power to a second motor 61. Analogously to the first motor terminal 20, the second motor terminal 20a is coupled to the supply terminals 11 via a transistor 23a. Furthermore, in the current paths of the motors 60, 61 current sensors 21, 21 a are connected, which are designed here as special resistors for current measurement, which are also referred to as a shunt. The first current sensor 21 or the second current sensor 21a are configured to measure a motor current via the first motor connection 20 or via the second motor connection 20a and via a measuring line to a first or second current sensor connection 33, 33a of the first control device 30. The first control device has an analog / digital converter 35 for converting the analog signals of the current sensors 21, 21a into digital signals.

The second transistor 23a is coupled to a second control output 31a of the first control device 30. At the second control output 31a, a second control signal MS2 for controlling the transistor 23a is emitted in the same way as in the first control output 31, which can differ from the first control signal MS1. Instead of the transistors 23, 23a, other controllable switching elements can be used.

Furthermore, a first and a second rotational speed sensor 22, 22 a are provided which are set up for measuring a rotational speed of the motors 60, 61 connected to the motor terminals 20, 20 a. The speed sensors 22, 22a each have a Hall sensor in this embodiment. However, it is also possible to provide further Hall sensors for the rotational speed sensors 22, 22a, which are used, for example, for determining the direction of rotation.

By the feedback of information about the currents flowing through the motors 60, 61 and the speeds of the motors 60, 61, a control loop can be formed, which allows an exact control of the movement of the drives. Thus, for example, the drive of motors that are theoretically the same design but production-related slight deviations have controlled synchronized. Likewise, different movements or deflections due to different mechanical loads of the motors can be compensated. In addition, a first and a second switching device 24, 24 a are provided for changing a polarity of the DC voltage which can be output at the first and second motor connection 20, 20 a, which are each coupled to a first or second polarity output 36, 36 a of the first control device 30. In this case, the switching devices 24, 24a each comprise switches 241, 242 and 241a, 242a which can each be switched jointly and thus can influence a voltage or current direction through the motors 60, 61. This makes it possible, for example, to set the direction of rotation of the motors 60, 61.

In the exemplary embodiment shown, a voltage supply device 70 is also provided for supplying the operating device 40 with a rectified low voltage. The voltage supply device 70 in this case comprises a transformer 71, which converts the AC line voltage into a low voltage, which is required for the operation of the operating device, as well as a rectifier 72. The transformer 71 has only a low power to transmit and is therefore small and inexpensive. The voltage supply device 70 may also be provided for supplying power to the first control device 30. In this case, the transformer 71 can be set up for the electrically separate delivery of a first and a second low voltage, whereby the electrical isolation of the mains voltage area 1 and the low voltage area 2 is ensured.

Both the operating device 40 and the first control device 30 can also be supplied with an operating voltage via other supply sources, for example via batteries, rechargeable batteries or others from the AC adapter. independent sources of supply. Similarly, switching power supplies can be used for supply.

The control device 40 comprises, in addition to the first sensor means 41 designed as a push button, a second pushbutton 42. The switching states of the pushbuttons 41, 42 are transmitted via optocouplers 51, 52 of the galvanically separating coupling 50 to the control connection 32 of the first control device 30.

The generation of the control signals MS1, MS2 takes place in the control device 30, which is embodied for example as a microcontroller. The operating device 40 is used in this embodiment only for the transmission of tactile commands of the user.

FIG. 4 shows a further exemplary embodiment of a controller according to the invention. In this case, a transistor bridge with transistors 231, 232, 233, 234 is provided in the mains voltage range 1, the two connected to the supply terminals 11 paths each having two connected in series

Transistors 231, 232, 233, 234 has. The control terminals of the transistors 231, 232, 233, 234 are coupled to the first control output 31. The connection nodes of the two series-connected transistors 231, 232 and 233, 234 form the first motor connection 20.

By a simultaneous activation of the transistors 231, 234 or the transistors 232, 233, the DC voltage of the rectifier 10 is output at the motor terminal 20. To change the polarity of the voltage at the motor terminal 20 and thus the direction of rotation of the motor, the drive is reversed, so that either the transistors 231, 234 or the transistors 232, 233 are driven. One Current path for the current through the motor terminal 20 is thus alternatively formed by the transistors 231, 234 or the transistors 232, 233. As the control signal MS1 as in the embodiment of Figure 1, a pulse width modulated signal can be used, which in each case alternatively the transistors 231, 234 or the transistors 232, 233 is supplied.

FIG. 5 shows a further embodiment of a controller according to the invention. In this case, the operating device 40 comprises a second control device 43, which is set up to control at least the first motor connection 20. A second motor connection 20a is shown only by way of example in FIG. 3. The speed sensors 22, 22a are connected via connections 44, 44a to the second control device 43, which is embodied for example as a microcontroller. The switching states of the buttons 41, 42 are received via the second control device 43.

The first and second control devices 30, 43 are coupled via a serial connection via the galvanically isolating coupling 50. The coupling 50 comprises a first optocoupler 51 for transmitting data from the second to the first control means 43, 30 and a second optocoupler 53 for transmitting data from the first to the second control means 30, 43. The coupling 50 thus provides a bidirectional connection between the control devices 30, 43. The connection may alternatively be designed as a unidirectional connection.

The current sensors 21, 21a are, as also shown in FIG. 3, coupled to the first control device 30. The information from the current sensors 21, 21a can thus be transmitted via the coupling 50 to the second control device 43. be telt. A regulation of the voltages at the motor terminals 20, 20a or the motors 60, 61 can thus take place completely in the second control device 43, while the first control device 30 generates the control signals MS1, MS2 as a function of the information transmitted by the second control device 43.

In the illustrated embodiment, the rectifier 10 is coupled via a power disconnect relay 13 to the power terminals 12 for supplying the AC line voltage. Since the power supply device 70 is fixedly coupled to the mains terminals 12, the second control device 43 remains supplied with voltage even if the rectifier 10 is disconnected from the mains terminals 12 via the mains disconnecting relay 13 ,

Due to the separation of the mains voltage range 1 of the AC mains voltage this is completely de-energized. This results in a higher level of electrical safety for the user. For example, the mains AC voltage is disconnected by the power disconnect relay 13 at standstill of the motors from the mains voltage range.

A power disconnect relay 13 can also be used in an embodiment according to one of the figures 1 to 4. In this case, there is a control of the power disconnect relay 13 for opening the relay, that is, for disconnecting the AC line voltage by the first control device. Since this may also be disconnected from the power supply after disconnection, for example, in the case of a supply from the mains voltage range 1, it is necessary in this case for the relay to close, that is to say to connect to the AC line voltage via a control voltage from the area of the operating device 40 is carried out.

FIG. 6 shows an alternative exemplary embodiment of a control according to the invention, in which the rectifier 10 is coupled via a network disconnecting relay 13 to the mains connections 12 for supplying the mains alternating voltage. The control unit 130 has a first input 131 for supplying a control signal for closing the relay 13 and a second input 132 for supplying a control signal for opening the relay 13. The second input 132 is coupled to a relay control output 37 of the control device 30, so that a power-off of the mains voltage range 1 by the first control device 30 can take place. The first input 131 is coupled to the output of an OR gate 45 of the operating device 40, to which the input side, the buttons 41, 42 are connected. Thus, the power disconnect relay 13 can be controlled by an OR circuit of signals of the buttons 41, 42 and turn on the power supply for the mains voltage range 1.

FIG. 7 shows a further embodiment of a controller according to the invention. In this case, the mains voltage range 1 and the low voltage range 2 are arranged in a housing 100, wherein for mains voltage range 1 and low voltage range 2 also separate housing can be provided. The voltage supply device 70 comprises a transformer 71 having a first and a second secondary winding, to each of which a rectifier 72 is connected downstream, so that supply voltages for the operating device 40 and the first control device 30 can be electrically safely separated from each other. The lines from the mains rectifier 10 to the motor terminals 20, 20a, to which the usually relatively high rectified mains alternating voltage is applied, are provided with a shield SH. More generally, it is advantageous if the lines from the rectifier 10 to the supply terminals 11 and / or the lines from the supply terminals 11 to the motor terminals 20, 20a have a shield SH. The shield may comprise a metallic mesh or a metallic foil. However, such shielding can basically be provided for all lines in the mains voltage range 1.

In addition, on at least one side of the housing 100, a metallic foil 110 is attached, which is connected to a reference potential terminal GND. The metallic foil or alternatively a metallic plate should in this case be arranged so that an electric field, which is possibly generated during operation by the lines in the mains voltage range 1, is shielded towards the user. Therefore, as shown in the embodiment, it may be sufficient to mount the metallic foil 110 exclusively in the mains voltage region. The foil 110 can also extend over the entire area of the housing, comprising the mains voltage range 1 and the low voltage range 2.

With the film 110 can be limit values of the electric field, which are defined for example by regulations for electrically adjustable furniture comply. The lines from the motor terminals 20, 20a to the motors 60, 61, not shown here, should have a corresponding shielding.

In addition to the possibilities shown in the embodiments to control one or two motors, other motors can be controlled with a controller according to the invention. If the motors are mounted, for example, on a table with four legs each on a height-adjustable table leg, the four motors required, for example, can be controlled simultaneously via the control according to the invention. Advantageously, a feedback of engine data takes place, for example via respective rotational speed sensors and / or current sensors. This in turn allows a synchronous control of the motors and thus a uniform lifting of the table.

When using the control with electrically adjustable beds, it is possible to control different directions of movement or setting options of the bed via different motors. Also, it is possible that several motors or a group of motors are controlled simultaneously.

LIST OF REFERENCE NUMBERS

1: mains voltage range

2: low voltage range

10: rectifying supply device

11: Supply connections

12: Power connections

13: Mains isolation relay

14: AC voltage sensor

20, 20a: Motor connection

21, 21a: current sensor

22, 22a: Speed sensor

23, 23a: transistor

231, 232, 233, 234: transistor

T1, T2, T3, T4: transistor

24, 24a: switching device

241, 242: switch

242a, 242a: switch

30, 43: Control device

31, 31a: control output

32: Operating connection

33, 33a: current sensor connection

34, 34a: speed sensor connection

35: analog / digital converter

36, 36a: polarity output

37: relay control output

38: AC voltage sensor input

40: Operating device

41, 42: sensor means

44, 44a: Speed sensor connection

45: Or gate

50: coupling

51, 52, 53: Optocouplers - I 9 ^¬

60, 61: Engine

70: Power supply device

71: Transformer

72: Rectifier 100: Housing

110: foil

130: relay control

131, 132: Relay control input

C: smoothing capacitor D: rectifier diode

MSl, MS2: control signal

SH: Shielding

Claims

claims

1. Control for electrically adjustable furniture, comprising - a mains voltage range (1) and a low voltage range (2), which are galvanically isolated; a rectifying supply device (10) which is arranged in the mains voltage range (1) and generates a rectified voltage applied to supply terminals (11) from an AC line voltage; a first motor terminal (20) which is arranged in the mains voltage range (1) and on which the rectified voltage applied to the supply terminals (11) can be delivered as a function of a first control signal (MS1); a first control device (30) which is arranged in the mains voltage range (1) and has an operating terminal (32) and a first control output (31) for outputting the first control signal (MS1); and - an operating device (40) arranged in the low-voltage region (2), which is connected to the operating connection (32) of the first control device (30) via a galvanically separating coupling (50).

2. Control according to claim 1, wherein for coupling the first motor terminal (20) to the supply terminals (11), a transistor (23) is provided whose control terminal is coupled to the first control output (31).

3. Control according to claim 1 or 2, wherein a first switching means (24) for changing a

Polarity of the first motor connection (20) can be issued rectified voltage is provided, which is coupled to a first polarity output (36) of the first control device (30).

4. The controller of claim 1, wherein a first transistor bridge (231, 232, 233, 234) is provided, the two connected to the supply terminals (11) paths each having two series-connected transistors (231, 232, 233, 234) whose control terminals are coupled to the first control output (31), wherein connection nodes of the two series-connected transistors (231, 232, 233, 234) are connected to the first motor terminal (20).

5. The controller of claim 1, wherein the rectifying supply device (10) comprises a second transistor bridge (Tl, T2, T3, T4), the two connected to power terminals (12) for supplying the AC line voltage paths each having two series-connected transistors ( Tl, T2, T3, T4) whose control terminals are coupled to the first control output (31), wherein connection nodes of the two series-connected transistors (Tl, T2, T3, T4) form the supply terminals (11).

6. Control according to claim 5, wherein the rectifying supply device (10) comprises an AC voltage sensor (14) which is coupled to an AC voltage sensor input (38) of the first control device (30) for determining a phase position of the mains AC voltage.

A controller according to any one of claims 1 to 6, wherein there is provided a first current sensor (21) arranged to measure a motor current across the first motor terminal (20) and coupled to a first current sensor terminal (33) of the first controller (30) is.

8. Control according to claim 7, wherein the first control means (30) comprises an analog-to-digital converter (35) for converting a signal of the first current sensor (21).

9. Control according to one of claims 1 to 8, wherein a first speed sensor (22) is provided which is adapted for measuring a rotational speed of the first motor connection (20) connected to the motor (60).

10. The controller of claim 9, wherein the first speed sensor (22) has at least one Hall sensor.

11. Control according to one of claims 1 to 10, wherein a voltage supply device (70) for supplying the first control device (30) and / or the operating device (40) is provided with a rectified Niederspan- voltage.

12. The controller of claim 11, wherein the voltage supply means (70) comprises a transformer (71) which is adapted for the electrically separate output of a first and a second low voltage.

13. Control according to one of claims 1 to 12, in which the first control device (30) is set up to output the first control signal (MS1) as a pulse-width-modulated signal.

14. Control according to one of claims 1 to 13, wherein a second motor terminal (20a) is provided, which is arranged in the mains voltage range (1) and in response to a second control signal (MS2) with the supply terminals (11) can be coupled, and the first control device (30) has a second control output (31a) for outputting the second control signal (MS2).

15. Control according to one of claims 1 to 14, wherein the operating device (40) comprises a second control device (43) which is adapted to control at least the first motor terminal (20).

16. Control according to one of claims 1 to 15, wherein the electrically isolating coupling (50) comprises at least one optocoupler (51, 52, 53).

17. Control according to one of claims 1 to 16, wherein the rectifying supply device (10) via a power disconnect relay (13) with power terminals (12) is coupled.

18. The controller of claim 17, wherein the power disconnect relay (13) by the first control device (30) and / or the operating device (40) is controllable.

19. Control according to one of claims 1 to 18, in which lines from the rectifying supply device (10) to the supply connections (11) and / or lines from the supply connections (11) to the first motor connection (20) have a shield (SH). exhibit.

20. The controller of claim 19, wherein the shield (SH) comprises a metallic mesh or a metallic foil.

21. Control according to one of claims 1 to 20, wherein at least the mains voltage range (1) in a housing (100) is arranged and at least on one side of the housing (100) a metallic foil (110) is attached, which with a reference potential terminal (GND) is connected.

22. Control according to one of claims 1 to 21, wherein the operating device (40) has at least one first sensor means (41, 42).

23. Use of a controller according to one of claims 1 to 22 in an electrically height-adjustable table.

24. Use of a controller according to any one of claims 1 to 22 in an electrically adjustable bed.