Abstract
An electromagnetic energy converter for a remote switch. The energy converter has an electrical coil and magnetic components, which comprise at least one permanent magnet and at least one ferromagnetic element. The permanent magnet and/or the ferromagnetic element are each movable between two extreme positions, where the movement of the permanent magnet and/or of the ferromagnetic element between the extreme positions leads to a directional reversal of a magnetic flux in the magnetic circuit. The magnetic flux is enclosed at least in part by the coil. At least one of the extreme positions is configured as a contactless extreme position at which at least two of the magnet components do not contact.
Claims
1. Electromagnetic energy converter for a remote switch, the energy converter having magnetic components for generating a magnetic circuit, the magnetic components comprising at least one permanent magnet and at least one ferromagnetic element, and wherein the energy converter comprises at least one electrical coil, wherein the permanent magnet and/or the ferromagnetic element are each movable between two extreme positions, wherein the movement of the permanent magnet and/or the ferromagnetic element between the extreme positions results in a directional reversal of a magnetic flux in the magnetic circuit, wherein the magnetic flux is at least partially enclosed by the coil, wherein at least one of the extreme positions of the permanent magnet and/or the ferromagnetic element is configured as a contactless extreme position, at which at least two of the magnetic components do not contact each other, so that the magnetic circuit is completely closed at at least one location via non-ferromagnetic matter, and one or more other extreme positions are configured which differ from the contactless extreme position and at which at least two of the magnetic components contact each other.
2. The electromagnetic energy converter of claim 1, wherein the contactless extreme position is formed by an air gap between the two non-contacting magnet components.
3. Electromagnetic energy converter according to claim 1, wherein the contactless extreme position is formed by a non-ferromagnetic material arranged at least partially between the two non-contacting magnet components.
4. Electromagnetic energy converter according to claim 1, wherein the movement is a rotation about an axis of rotation with a defined angle of rotation defining the extreme positions.
5. Electromagnetic energy converter according to claim 4, wherein the angle of rotation is less than 30?, or less than 10?.
6. Electromagnetic energy converter according to claim 1, further comprising a spring element that is force-coupled to the ferromagnetic element and/or to the permanent magnet, wherein, by actuating the spring element, a spring force can be generated for the respective release of the ferromagnetic element and/or the permanent magnet against a magnetic holding force from one of the two extreme positions.
7. Electromagnetic energy converter according to claim 1, wherein the ferromagnetic element is configured as first ferromagnetic element and the magnet components comprise a second ferromagnetic element, wherein the first ferromagnetic element comprises a base portion and two legs formed thereon and is magnetically coupled at the base portion to the coil, and wherein the second ferromagnetic element is magnetically coupled to the permanent magnet and extends in a region of the two legs of the first ferromagnetic element, wherein the second ferromagnetic element is longer than a distance between the legs of the first ferromagnetic element, wherein the second ferromagnetic element at least partially overlaps with the legs of the first ferromagnetic element in a respective overlapping region for magnetic coupling.
8. Electromagnetic energy converter according to claim 7, wherein the second ferromagnetic element projects toward the base portion of the first ferromagnetic element on a side facing the base portion of the first ferromagnetic element in the respective overlapping region.
9. Electromagnetic energy converter according to claim 7, wherein the second ferromagnetic element protrudes beyond the legs of the first ferromagnetic element in a region on a side remote from the base portion of the first ferromagnetic element and has truncated corners in this region.
10. Electromagnetic energy converter according to claim 7, wherein the magnet components comprise a third ferromagnetic element, wherein the third ferromagnetic element is magnetically coupled to the permanent magnet, wherein the first ferromagnetic element is movable between the two extreme positions, wherein said first ferromagnetic element strikes with one of the two legs against the second ferromagnetic element in one of the two extreme positions and a distance is formed between the other of the two legs and the third ferromagnetic element, and in the other of the two extreme positions, strikes with the other of the two legs against the second ferromagnetic element and a distance is formed between the one of the two legs and the third ferromagnetic element.
11. Electromagnetic energy converter according to claim 10, wherein a distance is formed between the third ferromagnetic element and the permanent magnet.
12. Remote switch comprising an electromagnetic energy converter according to claim 1.
13. Remote switch according to claim 12, wherein the electromagnetic energy converter is embodied according to claim 6, wherein the remote switch comprises a release unit that is movably configured and coupled to the spring element of the energy converter for actuating the spring element.
14. Remote switch according to claim 13, further comprising a reset element for resetting the release unit to an initial position of the release unit.
15. Remote switch according to claim 12, further comprising one or more sensors for measuring measurement data of physical parameters from the environment.
Description
[0036] In the Figures:
[0037] FIG. 1A a schematic view of a top side of an exemplary embodiment of an energy converter according to the state of the art,
[0038] FIG. 1B schematized side view of the energy converter according to FIG. 1A in a first state,
[0039] FIG. 1C the energy converter according to FIG. 1B in a second state,
[0040] FIG. 2A a schematic view of a top side of a first exemplary embodiment of an energy converter according to the invention,
[0041] FIG. 2B schematized side view of the energy converter According to FIG. 2A in a first state,
[0042] FIG. 2C the energy converter according to FIG. 2B in a Second state,
[0043] FIG. 3 schematized view of a top side of a second exemplary embodiment of an energy converter according to the invention,
[0044] FIG. 4 schematized view of a top side of a third exemplary embodiment of an energy converter according to the invention,
[0045] FIGS. 5 to 8 each show a schematized view of a top side of the fourth to seventh exemplary embodiments of an energy converter according to the invention,
[0046] FIG. 9 perspective view of an exemplary embodiment of a remote switch according to the invention,
[0047] FIG. 10 an exploded view of the remote switch according to FIG. 9.
[0048] Firstly, with reference to FIGS. 1A to 1C, an exemplary embodiment of a prior art energy converter is explained.
[0049] FIG. 1A shows a schematized view of a top side of such an energy converter. The energy converter has a ferromagnetic element 1 which has a base portion 11 and legs 10a and 10b formed thereon in a U-shape. An electrical coil 9 is magnetically coupled to the base portion 11 with the ferromagnetic element 1. The electrical coil 9 is thereby wound around the base portion 11. The coil 9 is configured to generate, by magnetic induction, an electric voltage at two terminals. A spring element 3 is arranged on the right leg 10b, which is configured to actuate the energy converter, as will be explained in more detail below. The ferromagnetic element 1 is movably mounted about an axis of rotation A.
[0050] Furthermore, the energy converter comprises a second ferromagnetic element 2a. The second ferromagnetic element 2a is magnetically coupled to a permanent magnet 8 (see FIGS. 1B and 1C) and extends in a region of both legs 10a and 10b of the first ferromagnetic element 1. The second ferromagnetic element 2a is longer than a distance between the legs 10a and 10b of the first ferromagnetic element 1, wherein the second ferromagnetic element 2a partially overlaps with the legs 10a and 10b of the first ferromagnetic element 1 in a respective overlapping region for magnetic coupling.
[0051] Further, the energy converter has a third ferromagnetic element 2b (see FIGS. 1B and 1C) arranged on a side of the permanent magnet 8 opposite to the second ferromagnetic element 2a and magnetically coupled thereto. In this way, the ferromagnetic elements 2a and 2b are magnetically coupled to different magnetic poles of the permanent magnet 8. The permanent magnet 8 and the ferromagnetic elements 2a and 2b form a group of magnetic components for generating a magnetic circuit.
[0052] Hereinafter, the operation of this prior art energy converter is described with reference to FIGS. 1B and 1C, which respectively show a side view of the energy converter in various states. As explained above, the ferromagnetic element 1 is enclosed by the electrically conductive coil 9. Furthermore, the magnetic circuit is completed by the ferromagnetic elements 2a and 2b and the permanent magnet 8. According to the state in FIG. 1B, the first ferromagnetic element 1 touches, with its two legs 10a and 10b at two contact points 7, the second and third ferromagnetic elements 2a and 2b, which are magnetized via the permanent magnet 8 (magnetically opposite poles). The leg 10a touches the third ferromagnetic element 2b at a lower contact point 7 on the left side, and the leg 10b touches the second ferromagnetic element 2a at an upper contact point 7 on the right side.
[0053] A magnetic flux thus propagates, starting from the permanent magnet 8, through the ferromagnetic elements 2a and 2b that are in contact with it, and then passes through the two contact points 7 into the ferromagnetic element 1, where it closes. The two contact points 7 thereby allow a reduction of the magnetic resistance in the magnetic circuit, wherein a comparatively high magnetic flux can be achieved. In addition, the two contact points 7 allow an abrupt and strong change of the magnetic flux upon opening and closing of the contact points 7, which will be explained in more detail below.
[0054] As explained above, in this exemplary embodiment the ferromagnetic element 1 is movably mounted and pivotable about the axis of rotation A (see FIG. 1A) via a rotation 5 within a predetermined angle of rotation (e.g. <30? or <10?). The axis of rotation A goes into the drawing plane in FIGS. 1B and 1C. The ferromagnetic element 1 can be rotated in a seesaw-like manner by the application of force 4 to the spring element 3 through a certain angle of rotation, wherein the two end positions (extreme positions) shown in FIGS. 1B and 1C can be assumed. In these two end positions, the ferromagnetic element 1 alternately strikes corresponding points of the ferromagnetic elements 2a and 2b at the respective contact points 7 with the two legs 10a and 10b. Due to the application of force 4 to spring element 3, ferromagnetic element 1 is transferred from the position (state) in FIG. 1B to the position (state) in FIG. 1C.
[0055] The rotation 5 takes place abruptly due to magnetic holding forces in the contact points 7, wherein the spring element is initially deformed without any movement of the ferromagnetic element 1 taking place. The magnetic holding forces hold the ferromagnetic element 1 in one of the end positions. Only when the force 4 exerted by the spring element 3 exceeds the magnetic holding forces is there an abrupt flip to the other end position (extreme position) and two new contact points 7 (see transition from FIG. 1B to FIG. 1C and vice versa) through which the magnetic flux is now conducted. In both end positions (FIGS. 1B and 1C), the magnetic flux through ferromagnetic element 1 is at a maximum, but in each case in the opposite direction. This means that a reversal of the direction of the magnetic flux occurs, which causes the intended voltage induction in the electrical coil 9.
[0056] The energy converter according to the principle as shown in FIGS. 1A to 1C, has the following disadvantages: [0057] Mechanical overdetermination. This comes from the bearing position (axis of rotation) A of the movable ferromagnetic element 1 and from the respective two magnetic contact positions 7. Since all three positions ideally lie on a straight line, a consistently exact function can only be achieved by extreme precision of the parts and components used. Even very small deviations (tolerances), which are unavoidable in production, have a strong influence on the function of the energy conversion, which ultimately results in a poor production yield (energy conversion). [0058] Strong force peaks in the extreme positions. The force curve of the movable ferromagnetic element 1 is proportional to the cube of the distance between the contact points 7. Therefore, strong force changes occur in the boundary region to these contact points 7. These aggravate the problem of high tolerance requirements and lead to magnetic saturation of the ferromagnetic material in the contact points 7, which reduces the efficiency of the energy conversion. Furthermore, the force peaks occasionally cause the ferromagnetic element 1 to detach from each of the two contact points 7 non-simultaneously, which also has a negative effect on the efficiency of energy conversion. [0059] High noise generation. In the course of motion the force peaks also lead to high noise generation when the movable ferromagnetic element 1 hits the attachment positions at the contact points 7 with the ferromagnetic elements 2a and 2b. This is undesirable if the energy converter is used, for example, in remote switches in buildings.
[0060] These disadvantages are overcome by an energy converter according to the invention. With reference to FIGS. 2A to 2C, an exemplary embodiment of an energy converter according to the invention is explained.
[0061] The inventive energy converter of to the embodiment according to FIGS. 2A to 2C comprises the same components as the energy converter according to the embodiment of FIGS. 1A to 1C. The same components are marked with the same reference signs, and reference is made to the above explanations for corresponding functionalities. However, the energy converter of the embodiment according to FIGS. 2A to 2C has significant differences in its configuration compared to the energy converter of the embodiment according to FIGS. 1A to 1C. These differences will be explained below.
[0062] One significant difference is that the magnetic circuit is not completely closed in said end positions (compare FIGS. 2B and 2C with FIGS. 1B and 1C) of the ferromagnetic element 1. In contrast to the energy converter according to the embodiment of FIGS. 1A to 1C, the energy converter according to the embodiment of FIGS. 2A to 2C has defined distances 6, 16 at predetermined locations between the magnetic components involved in the magnetic circuit at the respective end positions. As can be seen from FIG. 2B, in this end position the ferromagnetic element 1 touches the ferromagnetic element 2a only with its leg 10b on the right side at the upper contact point 7. The other leg 10a of the ferromagnetic element 1 is spaced apart from the ferromagnetic element 2b by a distance 6 on the left side in this end position. As can be seen from FIG. 2C, in this end position the ferromagnetic element 1 touches the ferromagnetic element 2a only with its leg 10a on the left side at the upper contact point 7. The other leg 10b of the ferromagnetic element 1 is spaced apart from the ferromagnetic element 2b by a distance 6 on the right side in this end position.
[0063] In addition, a distance 16 is also configured between the permanent magnet 8 and the ferromagnetic element 2b by way of example. In alternative embodiments, the distance 16 is omitted or is configured between the permanent magnet 8 and the ferromagnetic element 2a or between the permanent magnet 8 and the ferromagnetic elements 2a and 2b, respectively. In the embodiment according to FIGS. 2A to 2C, the explained distances 6, 16 are air gaps. In alternative embodiments, the distances are realized via non-ferromagnetic material introduced between the respective magnet components. Via the explained distances 6, 16, contactless extreme positions of the ferromagnetic element 1 are realized with respect to its leg 10a in FIG. 2B and with respect to its leg 10b in FIG. 2C.
[0064] These measures at first seem absurd in the sense of the most efficient and effective utilization of a magnetic flux for the (in any case difficult) object of efficient energy conversion. This is because these measures initially lead to a weakening of the magnetic flux and are thus detrimental to the energy density and efficiency of the energy converter.
[0065] However, it has been found that the configuration of the energy converter, as exemplified in the embodiment shown in FIGS. 2A to 2C, has the following advantages: [0066] Definiteness of the mechanical system. Due to the fact that the movable ferromagnetic element 1 now has only two instead of three mechanical determinations in the respective end positions (the axis of rotation A and one of the contact points 7 in each case), the mechanical system is precisely determined. Small tolerances of the parts and magnet components, which are unavoidable in production, can be tolerated without loss of function or reduction in yield. The non-simultaneous detachment of two contact points 7 is avoided. [0067] Avoidance of extreme force peaks. Distance 6 permits linearization of the force curve. Extreme force gradients in the vicinity of contact points 7 can be avoided. [0068] Furthermore, the saturation tendency of the ferromagnetic elements at contact points 7 can be reduced. [0069] Lower noise generation. The moderate magnetic forces which act on the movable ferromagnetic element 1 have a positive effect on noise generation.
[0070] FIGS. 3 and 4 show a schematic view of a top side of a second and third exemplary embodiment of an energy converter according to the invention, respectively. In FIGS. 3 and 4, the energy converter is constructed analogously to the energy converter according to the embodiment of FIGS. 2A to 2C. The same components are marked with the same reference signs, and reference is made to the above explanations for corresponding functionalities. However, the energy converter in the embodiments according to FIGS. 3 and 4 has differences in the geometry of the ferromagnetic element 2a compared to the configuration according to FIGS. 2A to 2C.
[0071] While the exemplary embodiment of the ferromagnetic element 2a in FIG. 2A is rectangular, more complex geometries are realized in the embodiments of FIGS. 3 and 4. In particular, in both embodiments of FIGS. 3 and 4, the overlaying surface areas in a respective overlapping region between the legs 10a and 10b of the ferromagnetic element 1 and the ferromagnetic element 2a are enlarged. This is achieved by projecting the second ferromagnetic element 2a toward the base portion 11 of the first ferromagnetic element 1 on a side facing the base portion 11 of the first ferromagnetic element 1 in the respective overlapping region. For this purpose, the second ferromagnetic element 2a has corresponding projections 12a and 12b. This has the advantage that the effective magnetic flux is increased.
[0072] In addition, in the embodiment according to FIG. 4, the second ferromagnetic element 2a is reduced in area on a side remote from the base portion 11 of the first ferromagnetic element in a respective region in which it projects beyond the legs 10a and 10b of the first ferromagnetic element 1 This is achieved by the second ferromagnetic element 2a having angled corners on this remote side in the respective region. This has the advantage of reducing parasitic magnetic flux. In a centrally located region of the second ferromagnetic element 2a between the two legs 10a and 10b, however, the second ferromagnetic element 2a is not reduced in area in the embodiment according to FIG. 4. Rather, in this area a strong magnetic coupling with the permanent magnet 8 is realized over the largest possible area of the second ferromagnetic element 2a (compare above explanations).
[0073] The advantages of the more complex geometries of the second ferromagnetic element 2a shown in the embodiments of FIGS. 3 and 4 are thus to optimize the ratio of beneficial magnetic flux (through the ferromagnetic element 1) and parasitic magnetic flux (all magnetic fluxes originating from the permanent magnet 8 but not passing through the ferromagnetic element 1). This directly benefits the efficiency of energy conversion by reducing parasitic magnetic fields that do not contribute to induction through the coil but can cause forces.
[0074] FIGS. 5 to 8 respectively show schematic views of a top side of fourth to seventh embodiments of an energy converter according to the invention.
[0075] The embodiments of FIGS. 5 and 6 relate to the design of the overlapping regions or overlapping surfaces for magnetic flux between the first ferromagnetic element 1 and the projections 12a and 12b of the second ferromagnetic element 2a. The overlapping regions are each shown hatched in FIGS. and 6 for clarity. Otherwise, the second ferromagnetic element 2a has angled corners 13a and 13b, as explained with respect to FIG. 4.
[0076] In FIG. 5, the overlapping regions between the respective projection 12a and 12b and the respective leg 10a and 10b are equal in area or symmetrically arranged. Additionally, in this case, the second ferromagnetic element 2a is also symmetrically arranged with respect to the two legs 10a and 10b. This represents a difference to an arrangement of the second ferromagnetic element 2a slightly offset to the left with respect to the two legs 10a and 10b according to the embodiments of FIGS. 2A to 2C, 3 and 4.
[0077] In FIG. 6, both an arrangement of the second ferromagnetic element 2a that is slightly offset to the right with respect to the two legs 10a and 10b as well as an asymmetry of the overlapping regions between the respective projection 12a and 12b and the respective leg 10a and 10b are shown. In particular, the overlap in area between the projection 12a and the leg 10a is smaller than the overlap in area between the projection 12b and the leg 10b. The sizes of the respective overlapping regions for the magnetic flux in the region of the contact points 7 (compare FIGS. 2B and 2C) are essentially responsible for the breakaway forces. An asymmetrical design compensates for an inequality of the breakaway forces in the two directions of motion, which is caused by the one-sided mounting of the spring element 3 in interaction with the finite stiffness of the structure.
[0078] The embodiments of FIGS. 7 and 8 concern the design with respect to the spring element or elements 3. In the embodiment according to FIG. 7, two spring elements 3a and 3b are arranged on opposite sides respectively, i.e. on both legs 10a and 10b. This can be particularly advantageous when realizing a bistable concept, since in this case actuating forces can act on the spring elements 3a and 3b in one direction in each case (e.g. in each case from below or in each case from above).
[0079] In the embodiment according to FIG. 8, a spring element 3 is arranged on the left leg 10a and is designed as a leaf spring with a trapezoidal shape. The spring element 3 is a highly stressed component and must survive several million switching cycles in industrial applications of the energy converter. A trapezoidal design of the geometry of the spring element 3 has the advantage that the stress is distributed more evenly when the spring element 3 is bent, resulting in an increased service life.
[0080] FIGS. 9 and 10 show a perspective view and an exploded view, respectively, of an exemplary embodiment of a remote switch 14 according to the invention. The remote switch 14 comprises an energy converter of the type explained above. In this way, the remote switch 14 can be constructed as an energy-autonomous remote switch 14. While FIGS. 2A to 8 are schematic representations, FIGS. 9 and 10 show views of an actual technical implementation.
[0081] For realization as an energy-autonomous remote switch it is useful to realize in the remote switch 14, in addition to the energy converter, a short-term storage device for electrical energy, a voltage converter and radio electronics in a compact module that has mechanical interfaces for force application as well as sensor interfaces with which it is possible to distinguish between several different positions of force application.
[0082] FIG. 9 shows the remote switch 14 in an assembled state. FIG. 9 shows one of two release units 15, by means of which the energy converter can be triggered.
[0083] FIG. 10 shows the internal structure of the remote switch 14 in exemplary detail. Components 17 and 22 are the respective upper and lower outer housing parts (top side 17 and bottom side 22). The component 23 shows the described electromagnetic energy converter with the spring element 3. A printed circuit board 24 carries at least the following components: voltage rectifier, short-time energy sensor, voltage regulator, microcontroller, radio unit and radio antenna 20. In addition to the radio antenna 20, a wireless interface 21 is configured for further communication. The wireless interface 21 is, for example, an NFC interface.
[0084] Furthermore, optionally there are one or more sensors 25a, 25b, 25c, 25d. These are exemplarily realized here as conductor tracks on the printed circuit board 24 and are bridged by the keypad mat 19, more precisely by its electrically conductive sections 26a to 26d, as soon as a force is applied to the sensor interfaces 27a to 27d mechanically connected thereto on the top side 17. The purpose of these sensors is to implement switches with multiple actuation interfaces, such as double rocker switches, which can be used to control multiple loads.
[0085] The release units 15 are levers which transmit the force to the spring element 3 when the remote switch 14 is actuated. The reset element 18 is a second spring element which returns the mechanism to its initial state as soon as the external force decreases sufficiently. A monostable mode of operation is implemented via the reset element 18. In alternative embodiments, the reset element 18 is not present, wherein a bistable mode of operation is realized.
[0086] The monostable and bistable modes of operation will be explained in more detail below.
[0087] The monostable mode of operation is shown in FIG. 10. Here, two spring elements 3 and 18 are always used. The first spring element 3 serves to accelerate the movement of the movable magnetic components of the energy converter 23. It ensures that a constant rapid movement of the movable magnetic components of the energy converter 23 is ensured regardless of the speed of the switch actuation. The second spring element 18 restores the initial state of the remote switch 14. Thus, as long as no external force is applied, the remote switch 14 only has a stable position.
[0088] Distinguished from this is an alternative, bistable system. In this case, the spring element 18 is omitted. The remote switch 14 flips to the respective other of two stable states when one of the release units 15 is actuated. The remote switch 14 is not reset until a new actuation takes place on one of the release units 15.
[0089] The geometries described here are shown only as examples and can also be designed differently. Likewise, in embodiments not shown, moving and stationary parts exchange roles, since only relative movement is important. All the embodiments explained have been chosen merely by way of example.
LIST OF REFERENCE SIGNS
[0090] 1 first ferromagnetic element (core) [0091] 2a second ferromagnetic element (armature) [0092] 2b third ferromagnetic element [0093] 3 spring element [0094] 3a, 3b spring element [0095] 4 application of force [0096] 5 rotation around an angle [0097] 6 distance [0098] 7 contact point [0099] 8 permanent magnet [0100] 9 electrical coil [0101] 10a, 10b leg [0102] 11 base portion [0103] 12a, 12b projections [0104] 13a, 13b angled corners [0105] 14 remote switch [0106] 15 release unit [0107] 16 distance [0108] 17 top side [0109] 18 reset element, spring [0110] 19 keypad mat [0111] 20 radio antenna [0112] 21 wireless interface [0113] 22 bottom side [0114] 23 module [0115] 24 printed circuit board [0116] 25a to 25d sensors [0117] 26a to 26d conductive sections [0118] 27a to 27d sensor interfaces [0119] A rotary axis
