WO2017030498A1 - A press-type energy harvesting device for wireless smart switches - Google Patents

An energy harvesting device for converting mechanical energy to electrical energy, comprising a switch made of a permanent magnet sandwiched by yokes that act as flux guides, a magnetic core, an electrically conductive coil wound around the core, and a shielding enclosure. The core is magnetically coupled to the permanent magnet through the yokes; displacement of the magnet between two positions located opposite to each other changes the magnetization of the core and consequently induces a voltage in the coil according to Faraday's Law. When the switch is in a first position, a first yoke is in contact with the core and magnetizes the core in a first direction. Mechanical pressing of the switch displaces the switch away from the first position to a second position and brings the second yoke in contact with the core thereby reversing the direction of magnetization of the core and inducing a voltage in the electrically conductive coil. This miniature energy harvesting device is intended for use in self-powered wireless switches.

i e nergy arves ng ev ce or re ess n i

Background

In this application, the energy harvesting device is able to generate adequate electric power operate extra-low power consumption circuit. This technology will improve the flexibility of remote control.

With development of technology of Internet of Things, more commercial products embedded with wireless function modules, such as wireless switches. For these smart switches, they request either electrical wiring or battery to operate the circuits.

However, they are not environment friendly. Firstly, battery has limited capacity and it needs to be replaced. Secondly, waste batteries contain hazardous chemicals. Thirdly, it requires construction works to install electrical wirings.

A miniaturization energy harvesting device is optimal choice to solve the problem and become environment friendly.

i e nergy arves ng ev ce or re ess n

Summary

According to an embodiment, a press-type energy harvesting device could convert the mechanical energy to electric energy with a press action. The energy harvesting device comprises a straight iron core, a surround-type extension of the straight iron core, a copper coil, a strong NeFeB magnet, and two magnet yokes. The straight core is winded by the coil, of which one end is connected with the surround-type extension, and the other end is inserted between the two magnet yokes. The two yokes sandwich the strong NeFeB magnet, forming an integrated module named "U-type" magnet. This "U-type" magnet could move up and down relative to the straight core, changing the contact status of the straight core with either N pole or S pole of the magnet. Along with this movement, the direction of magnetic induction line inside the straight core will reverse, causing a significant change of the magnetic flux which will generate current in the coil winded on the straight core according to Faraday's law of induction. The surround-type extension of the straight core used here could reduce the resistance of the magnet loop, thus enhancing the induced electromotive force. The energy harvesting device presented here converts mechanical energy to electric energy by utilizing a standard press action of the switches. It has many advantages including simple structure, small size and environment friendly. Therefore, it could be used in various applications including wireless switches.

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Brief Description of the Drawings

In the drawings, they generally refer to the same parts throughout the different views. The drawings are to illustrate the principles of the invention. It should not be constrained to scale. Other equally effective embodiments are also in the scope of this invention. In the following description, various embodiments of the invention are described with reference to the following drawings, in which:

Figure 1 illustrates a schematic 3-D view of the overall structure of a press-type energy harvesting device, according to an embodiment.

Figure 2 illustrates a schematic lateral view of the movement of the "U-type" magnet comprised of the magnet and yokes relative to the straight core, according to an embodiment.

Figure 3 (a) and (b) illustrates schematic 3-D views of different two shapes of the surround-type extension of the straight core which are specifically called as left and right surrounding and four directions surrounding respectively, according to an embodiment.

In the drawings, the reference numbers are corresponding to: 1. a straight core, 2. a surround-type extension of the straight core, 3. copper coils, 4. a magnet, 5. a yoke, 6. a yoke. i e nergy arves ng ev ce or re ess n i

Detailed Description

The following detailed description refers to the accompanying drawings that show specific details and embodiments in which the invention will be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to apply the invention. The various embodiments are not necessarily mutually exclusive, because some embodiments could be combined with one or more other embodiments to form new embodiments.

Below are the further and detailed instructions about the embodiments of the invention in conjunction with the accompanying drawings.

As shown in Fig. 1 to 3, the press-type energy harvesting device includes a straight core 1, a surround-type extension 2 of the core 1, a copper coil 3, a strong NeFeB magnet 4, and two magnet yokes 5 and 6. The copper coil 3 is winded outside the straight core 1. The N pole and S pole of the magnet 4 are in contact with the magnet yokes 5 and 6, respectively. That is, the two magnet yokes 5 and 6 sandwich the magnet 4, in this way the magnet 4 and yokes 5 and 6 entirely form a special magnet with the shape of "U-type". One end of the straight core 1 is connected with the surround-type extension 2. And the other end is inserted between the two magnet yokes 5 and 6, in other words, in the groove of the special "U-type" magnet. The integrated special "U-type" magnet could move up and down relative to the straight core 1.

Figure 3 shows several embodiments of the surround-type extension 2 of the straight core 1. There are totally three main shapes, depending on how many directions of the straight core the surround-type extension will cover, to be specific, the surround-type extension may surround up and down, left and right, and all the four directions of the i e nergy arves ng ev ce or re ess n i

straight core, respectively. The surround-type extension 2 is capable of enhancing the magnetic induction intensity through the straight core 1.

Figure 2 shows a schematic of how the special "U-type" magnet, which is comprised of the magnet 4 and the magnet yokes 5 and 6, moves up and down relative to the straight core 1. The special "U-type" magnet will be the press button in a specific application. When the "U-type" magnet completes a movement between up and down, the magnetic flux through the straight core 1 will reverse its direction, which equivalently means the magnetic flux through the copper coil 3 will also change its direction, so that the induced electromotive force will be generated in the coil 3.

The assembly of the device is simple. The induced electromotive force could generate adequate electrical power to operate low power consumption circuit. The press-type energy harvesting device can be applied to wireless smart switches and other relative applications such as car keys and handheld remote control.

1. A press-type energy harvesting device, which is comprised of:

a straight core that is made of iron;

a surround-type extension of the straight iron core, which is also made of iron;

a copper coil;

a strong NeFeB magnet;

two magnet yokes that is made of wrought iron;

2. The energy harvesting device as claimed in claim 1, wherein the copper coil is winded outside the straight core;

3. The energy harvesting device as claimed in claim 1, wherein the N pole and S pole of the magnet are connected to the two magnet yokes respectively, in other words, the magnet is between the two magnet yokes;

4. The energy harvesting device as claimed in claim 3, wherein all of the three components compose an integrated module which is just like a "U-type magnet", and this module is the main moving part that would move due to a press action;

5. The energy harvesting device as claimed in claim 1, wherein one end of the straight core is connected to the surround-type extension, and the other end of the straight core is in the middle of the two yokes, namely in the groove of the "U-type magnet";

6. The energy harvesting device as claimed in claim 1, wherein the surround-type extension of the straight iron core has several embodiments, and there are totally three main shape, depending on how many directions of the straight core the surround-type extension will cover, to be specific, the surround-type extension may surround up and

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SUBSTITUTE SHEETS (RULE 26) down, left and right, and all the four directions of the straight core, respectively;

7. The energy harvesting device as claimed in claim 4, wherein there is a spring or shrapnel connected to the "U-type magnet" module, which could restore the module to its original place after its movement caused by a press action.

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SUBSTITUTE SHEETS (RULE 26)