Abstract:
According to one exemplary embodiment, an electromechanical relay may be described. The relay can be constructed using printed circuit board (PCB) construction, and can have at least a pair of coils, for example one on the top of or above the PCB, the other on the bottom of or below the PCB, at least two ferromagnetic cores, one of which can be set at the center of each coil, at least a set of contacts which can be on the surface of the printed circuit board, a spacer which can be set between the coils, and a magnet which can be set within the spacer.

Description:
RELATED APPLICATIONS 
     This application is a Divisional of U.S. patent application Ser. No. 13/193,093, filed Jul. 28, 2011, which claims the benefit of U.S. Provisional Patent Application No. 61/368,411, filed on Jul. 28, 2010, and entitled, “Printed Circuit Board Embedded Relay”, the contents of which are incorporated herein by reference in their entirety. 
    
    
     BACKGROUND 
     A relay is a switch which is operated electromechanically. One common example of a relay consists of an electromagnet, an armature that is held in place by a spring, and a set of electrical contacts. When the electromagnet is energized, it attracts the armature, pulling it into the contacts, completing an electrical circuit. When current is no longer supplied to the electromagnet, the spring pushes the armature away from the contacts, breaking the circuit. Relays are useful in that they provide isolation between a controlling circuit and the circuit being controlled. This allows, for instance, a low-power circuit to safely control a high-power circuit, or to control several circuits at once. 
     Typically, relays are relatively large discrete components that must be attached individually to printed circuit boards (PCBs), which can be expensive and cumbersome. 
     SUMMARY 
     According to one exemplary embodiment, an electromechanical relay may be described. The relay can be constructed using printed circuit board (PCB) construction, and can have at least a pair of coils, for example one on the top of or above the PCB, the other on the bottom of or below the PCB, at least two ferromagnetic cores, one of which can be set at the center of each coil, at least a set of contacts which can be on the surface of the printed circuit board, a spacer which can be set between the coils, and a magnet which can be set within the spacer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Advantages of embodiments of the present invention will be apparent from the following detailed description of the exemplary embodiments. The following detailed description should be considered in conjunction with the accompanying figures in which: 
         FIG. 1  is an exploded view of an exemplary embodiment of a relay device. 
         FIG. 2  is an cross-sectional view of an exemplary embodiment of a relay device in a first position. 
         FIG. 3  is an cross-sectional view of an exemplary embodiment of a relay device in a second position. 
         FIG. 4  is an cross-sectional view of a second exemplary embodiment of a relay device in a first position. 
         FIG. 5  is an cross-sectional view of a second exemplary embodiment of a relay device in a second position. 
     
    
    
     DETAILED DESCRIPTION 
     Aspects of the present invention are disclosed in the following description and related figures directed to specific embodiments of the invention. Those skilled in the art will recognize that alternate embodiments may be devised without departing from the spirit or the scope of the claims. Additionally, well-known elements of exemplary embodiments of the invention will not be described in detail or will be omitted so as not to obscure the relevant details of the invention. 
     As used herein, the word “exemplary” means “serving as an example, instance or illustration.” The embodiments described herein are not limiting, but rather are exemplary only. It should be understood that the described embodiments are not necessarily to be construed as preferred or advantageous over other embodiments. Moreover, the terms “embodiments of the invention”, “embodiments” or “invention” do not require that all embodiments of the invention include the discussed feature, advantage or mode of operation. 
     Generally referring to  FIGS. 1-5 , an electromechanical relay that is built using printed circuit board construction is shown. The relay can be built by itself, in a switching array with other similar relays, or embedded within a printed circuit board (PCB) accompanied by other electronic components. 
     In  FIG. 1 , an exemplary embodiment of a relay device  100  can be shown. Relay device  100  may include coil  102 , which can be contained in coil layer  104 , and coil  106 , which can be contained in coil layer  108 . Coil  102  and coil  106  can be wired in series, in parallel, or operated independently, for example, at different current levels or energized in time in a staggered manner. 
     Coil layer  104  and coil layer  108  can contain one or more sublayers in a manner of accommodating the windings of coil  102  and coil  106  respectively. Coil layer  104  and coil layer  108  can be constructed in such a way that the central via, or through-connection, that passes through each sublayer may only connect one sublayer with the next. Coil layer  104  and coil layer  108  can further be constructed so that more than one sublayer is laminated together in such a way that epoxy resin or other pre-impregnated composite flows over the edges of the central hole, which can insulate vias above one another from each other. 
     A magnet  110  can be located between coil  102  and coil  106 . Magnet  110  can be cylindrical in shape and can be polarized along its axis. Magnet  110  can be coated in a conductive material, for example gold, which can facilitate electrical conduction. Magnet  110  can be contained within a spacer  112 . Additionally, magnet  110  can be any size or shape, as desired. In one exemplary embodiment, magnet  110  can be between about 1.5 mm and 1.6 mm in diameter and between about 0.7 mm and 0.8 mm in length. 
     Spacer  112  can be a layer of PCB material void of copper, which can contain a bore, hole or space  113 . Additionally, spacer can be any size or shape, for example between about 1.5 mm and about 1.6 mm thick. Bore  113  can be sized in such a way that magnet  110  can be contained inside with little freedom of movement laterally but some freedom of movement along its axis. 
     Disposed between coil layer  104  and spacer  112  may be contact layer  114 . Contact layer  114  can be constructed so as to contain an electrical contact structure  122  positioned in such a way that a circuit is closed when magnet  110  is positioned proximate to it. Disposed between coil layer  108  and spacer  112  may be contact layer  116 . Contact layer  116  can be constructed so as to contain an electrical contact structure  124  positioned in such a way that a circuit is closed when magnet  110  is positioned proximate to it. 
     The thickness of spacer  112  can be greater than the thickness of magnet  110  so that magnet  110  can move within hole  213  in spacer  112  to touch either contact layer  114  or contact layer  116 . For example, if spacer  112  is about 1.6 mm thick and magnet  110  is about 1.6 mm in diameter and about 0.8 mm in length, magnet  110  can be able to move with a stroke of about 0.8 mm within spacer  112 . 
     A ferromagnetic core  118  can be located inside coil  102 , and can be secured in place within coil layer  104  by glue, epoxy resin, or any other fastener. A similar core  120  can be located inside coil  106 , and can be similarly secured within coil layer  108 . Core  118  and core  120  can be made of steel, iron, or other similar material as desired and as known in the art. Core  118  can be positioned so that when it attracts magnet  110 , magnet  110  can be held in place against contact layer  114 . Similarly, core  120  can be positioned so that when it attracts magnet  110 , magnet  110  can be held in place against contact layer  116 . 
     Coil layer  104 , spacer  112 , and coil layer  108 , as well as contact layers  114  and  116 , can be fastened together through the use of screw  132 , screw  134 , screw  136 , and screw  138 . Alternatively, they can be secured with glue, epoxy resin, or in any other manner known in the art. For example, where it may be desirable to form a relay device, such as relay device  100 , in a compact fashion, an epoxy or other known adhesive may be used to couple coil layer  104 , spacer  112  and coil layer  108 , as well as contact layers  114  and  116 . However, it should be appreciated that different orientations, layouts, constructions and sizes of exemplary relay device  100  may be utilized as desired. 
     Turning to  FIGS. 2-3 , relay device  100  can operate in the following manner, although other manners of implementation may be utilized as desired. As relay  100  may be bi-stable, a current pulse can be used to set the relay  100  and a pulse of opposite polarity may reset the relay  100 . Therefore, coil  102  and coil  106  can be oriented so that when energized, the same magnetic polarity faces inward from each of coil  102  and coil  106 , respectively, toward magnet  110 . Then magnet  110  can be simultaneously attracted to one coil and repelled from the other. For example, if magnet  110  is attracted to coil  102 , it can then be held in place by core  118  against contact layer  114 . Magnet  110  can then form an electrically conductive bridge across the contacts  122 , which may be gold plated, located on contact layer  114 , completing a circuit. If the polarity of the current pulse is reversed, magnet  110  can be pushed away from coil  102  and may be pulled toward coil  106 , and then may be held in place by core  120  against contact layer  116 . Magnet  110  can then form an electrically conductive bridge across the contacts  124  located on contact layer  116 , for example, completing a different circuit. 
     In further exemplary embodiments, relay device  100  may be used in any manner desired. For example, relay device  100  may be used as a switching device. In other exemplary embodiments, relay device  100  may be used with any number of other relay devices, for example in a switching array with, for example, other similar relays. Additionally, relay device  100  may be embedded within a PCB and can be accompanied by any number of additional electronic components. 
     Turning to  FIGS. 4-5 , another exemplary embodiment of a relay device  200  can be disclosed. Relay device  200  can include most of the components of relay device  100 , which are referenced with identical numerals and can be understood to have substantially the same functionality. 
     Relay device  200  may further include a coil  202 , which can be contained in coil layer  204 . Coils  102 ,  106  and  202  can be wired in series, in parallel, or operated independently, for example, at different current levels or energized in time in a staggered manner. 
     Coil layer  204  can contain one or more sublayers in a manner of accommodating the windings of coil  202 . Coil layer  204  can be constructed in such a way that the central via, or through-connection, that passes through each sublayer may only connect one sublayer with the next. Coil layer  204  can further be constructed so that more than one sublayer is laminated together in such a way that epoxy resin or other pre-impregnated composite flows over the edges of the central hole, which can insulate vias located above one another from each other. 
     A magnet  210  can be located between coil  202  and coil  106 . Magnet  210  can be cylindrical in shape and can be polarized along its axis. Magnet  210  can be coated in a conductive material, for example gold, which can facilitate electrical conduction. Magnet  210  can be contained within a spacer  212 . Additionally, magnet  210  can be any size or shape, as desired. In one exemplary embodiment, magnet  210  can be between about 1.5 mm and about 1.6 mm in diameter and between about 0.7 mm and about 0.8 mm in length. 
     Spacer  212  can be a layer of PCB material void of copper, which can contain a bore, hole or space  213 . Additionally, spacer  212  can be any size or shape, for example between about 1.5 mm and about 1.6 mm thick. Bore  213  can be sized in such a way that magnet  210  can be contained inside with little freedom of movement laterally but some freedom of movement along its axis. 
     Disposed between coil layer  108  and spacer  112  may be contact layer  116 . Contact layer  116  can be constructed so as to contain an electrical contact structure  124  positioned in such a way that a circuit is closed when magnet  110  is positioned proximate to it. Disposed between coil layer  108  and spacer  212  may be contact layer  216 . Contact layer  216  can be constructed so as to contain an electrical contact structure  224  positioned in such a way that a circuit is closed when magnet  210  is positioned proximate to it. It should be noted that the embodiment of relay device  200  does not include a contact layer  114  disposed between coil layer  104  and spacer  112 , nor is any contact layer disposed between coil layer  204  and spacer  212 . Therefore, magnet  110  can move within hole  113  in spacer  112  to touch either core  118  or contact layer  116 . 
     The thickness of spacer  212  can be greater than the thickness of magnet  210  so that magnet  210  can move within hole  213  in spacer  212  to touch either core  218  or contact layer  216 . For example, if spacer  212  is about 1.6 mm thick and magnet  210  is about 1.6 mm in diameter and about 0.8 mm in length, magnet  210  can be able to move with a stroke of about 0.8 mm within spacer  212 . 
     A ferromagnetic core  218  can be located inside coil  202 , and can be secured in place within coil layer  204  by glue, epoxy resin, or any other fastener. Core  218  can be made of steel, iron, or other similar material as desired and as known in the art. Core  218  can be positioned so that when it attracts magnet  210 , magnet  210  can be held in place against core  218 . Similarly, core  120  can be positioned so that when it attracts magnet  210 , magnet  210  can be held in place against contact layer  216 . 
     Fastening of coil layer  204 , spacer  212 , as well as contact layer  216  can be achieved in any desired manner, including, but not limited to, as described above for the embodiment of relay  100 . 
     Relay device  200  can operate in the following manner, as shown in  FIGS. 4-5 , although other manners of implementation may be utilized as desired. As relay  200  may be bi-stable, a current pulse can be used to set the relay  200  and a pulse of opposite polarity may reset the relay  200 . Therefore, coil  102  and coil  106  can be oriented so that when energized, the same magnetic polarity faces inward from each of coil  102  and coil  106 , respectively, toward magnet  110 . Similarly, coil  202  may be oriented so that when energized, the same magnetic polarity faces inward from each of coil  202  and coil  106 , respectively, toward magnet  210 . Then magnets  110 ,  210  can be simultaneously attracted to one coil of the corresponding pair of coils and repelled from the other. In other words, coils  102  and  202  may be oriented such that, when energized, the magnetic polarities generated by coils  102  and  202  are oriented in the same direction, while the magnetic polarity of coil  106  is oriented in a direction opposite to that of coils  102  and  202 . 
     For example, if magnet  110  is attracted to coil  102 , it can then be held in place by core  118  against core  118 . Simultaneously, magnet  210  may be attracted to coil  202 , and can then be held in place by core  218  against core  218 . In this configuration, magnet  110 ,  210  do not bridge any circuits. 
     If the polarity of the current pulse is reversed, magnet  110  can be pushed away from coil  102  and may be pulled toward coil  106 , and then may be held in place by core  120  against contact layer  116 . Simultaneously, magnet  210  can be pushed away from coil  202  and may be pulled toward coil  106 , and then may be held in place by core  120  against contact layer  216 . Magnet  110  can then form an electrically conductive bridge across the contacts  124 , which may be gold plated, located on contact layer  116 , for example, completing a first circuit, while magnet  210  can then form an electrically conductive bridge across the contacts  224 , which may be gold plated, located on contact layer  216 , for example, completing a second circuit. 
     It should be appreciated that the embodiment of relay  200  is not limited to solely three coil layers, two contact layers, two spacers and two magnets. Additional layer groups may be added as desired. For example, another exemplary embodiment of relay  200  may include five coil layers, four contact layers, four spacers and four magnets. 
     In a further exemplary embodiment of the above, if alternate side contacts of relay devices  100 ,  200  are not used for switching signals, they may be used to monitor a switching state of the relay devices  100 ,  200 . 
     In other exemplary embodiments, relay devices  100 ,  200  may be utilized in systems that have a need for many interconnected relays and where the interconnected relays may be desired to be formed on a single PCB. This may allow for a decrease in manufacturing expenses as the number of PCBs which are utilized may be decreased. 
     The foregoing description and accompanying figures illustrate the principles, preferred embodiments and modes of operation of the invention. However, the invention should not be construed as being limited to the particular embodiments discussed above. Additional variations of the embodiments discussed above will be appreciated by those skilled in the art. 
     Therefore, the above-described embodiments should be regarded as illustrative rather than restrictive. Accordingly, it should be appreciated that variations to those embodiments can be made by those skilled in the art without departing from the scope of the invention as defined by the following claims.