Patent Publication Number: US-11640885-B2

Title: Rotary switch

Description:
CROSS REFERENCE TO RELATED APPLICATION AND CLAIM FOR PRIORITY 
     This application claims priority pursuant to 35 U.S.C. 119(a) of Indian Patent Application No. 202011002501, filed Jan. 20, 2020, which application is incorporated herein by reference in its entirety. 
     TECHNOLOGICAL FIELD 
     Example embodiments of the present invention relate generally to switch systems and, more particularly, to improved rotary switch configurations. 
     BACKGROUND 
     Medical equipment, computing devices, industrial controls, vehicle instrumentation, and related devices may rely on various sensors and switches during operation. For example, vehicles may leverage rotary switches to enable changes to the vehicle&#39;s operating state (e.g., various speeds) and/or to adjust various vehicle functions (e.g., head light intensity, wiper speed, etc.). However, the inventors have identified numerous deficiencies with these existing technologies in the field, the remedies for which are the subject of the embodiments described herein. 
     BRIEF SUMMARY 
     Apparatuses, systems, and associated methods of manufacturing are provided for switch systems. An example rotary switch may include a substrate and a plurality of electrical contacts supported by the substrate. The rotary switch may also include a resistor network including a plurality of resistors in electrical communication with the plurality of electrical contacts. The rotary switch may further include a commutator configured to move relative to the substrate along the plurality of electrical contacts. The commutator may be configured to electrically connect a pair of adjacent electrical contacts so as to modify an output voltage of the rotary switch corresponding to a position of the rotary switch. 
     In some embodiments, each resistor of the resistor network may be positioned so as to electrically connect a respective pair of adjacent electrical contacts. In such an embodiment, each resistor in the resistor network may define a resistance value that is different from resistance values of other resistors in the resistor network. 
     In some embodiments, the plurality of resistors may be connected in series between an input connection and an output connection. 
     In other embodiments, the commutator may be configured to electrically connect the pair of adjacent electrical contacts such that a resistor positioned in electrical communication between the pair of adjacent electrical contacts is bypassed. 
     In some further embodiments, the rotary switch may include a microcontroller operably coupled to the resistor network configured to determine the position of the rotary switch based on the output voltage. 
     In some embodiments, the plurality of electrical contacts may include a first set of electrical contacts and a second set of electrical contacts. In such an embodiment, the commutator may be configured to electrically connect pairs of adjacent electrical contacts of the first set, and a second commutator may be configured to electrically connect pairs of adjacent electrical contacts of the second set. 
     In any embodiment, the substrate may be formed as a disk. As such, the plurality of electrical contacts may be positioned along a peripheral edge of the disk and/or the substrate may define an opening positioned at the center of the disk. 
     The above summary is provided merely for purposes of summarizing some example embodiments to provide a basic understanding of some aspects of the invention. Accordingly, it will be appreciated that the above-described embodiments are merely examples and should not be construed to narrow the scope or spirit of the invention in any way. It will be appreciated that the scope of the invention encompasses many potential embodiments in addition to those here summarized, some of which will be further described below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Having described certain example embodiments of the present disclosure in general terms above, reference will now be made to the accompanying drawings. The components illustrated in the figures may or may not be present in certain embodiments described herein. Some embodiments may include fewer (or more) components than those shown in the figures. 
         FIG.  1    is a perspective view of an example switch system for implementing some example embodiments described herein; 
         FIG.  2    is a perspective view of a rotary switch according to an example embodiment; 
         FIG.  3    is a portion of the rotary switch of  FIG.  2    according to an example embodiment; and 
         FIG.  4    is an example circuit diagram of the rotary switch of  FIG.  2    including a microcontroller according to an example embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Overview 
     The present invention now will be described more fully hereinafter with reference to the accompanying drawings in which some but not all embodiments of the inventions are shown. Indeed, these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout. As used herein, terms such as “front,” “rear,” “top,” etc. are used for explanatory purposes in the examples provided below to describe the relative position of certain components or portions of components. Furthermore, as would be evident to one of ordinary skill in the art in light of the present disclosure, the terms “substantially” and “approximately” indicate that the referenced element or associated description is accurate to within applicable engineering tolerances. 
     As used herein, the term “comprising” means including but not limited to and should be interpreted in the manner it is typically used in the patent context. Use of broader terms such as comprises, includes, and having should be understood to provide support for narrower terms such as consisting of, consisting essentially of, and comprised substantially of. 
     As used herein, the phrases “in one embodiment,” “according to one embodiment,” “in some embodiments,” and the like generally refer to the fact that the particular feature, structure, or characteristic following the phrase may be included in at least one embodiment of the present disclosure. Thus, the particular feature, structure, or characteristic may be included in more than one embodiment of the present disclosure such that these phrases do not necessarily refer to the same embodiment. 
     As used herein, the word “example” is used herein to mean “serving as an example, instance, or illustration.” Any implementation described herein as “example” is not necessarily to be construed as preferred or advantageous over other implementations. Although described herein with reference to a rotary switch, the features, configurations, and devices of the present application may also be applicable to other switch devices, applications, and circuits. 
     Switch System 
     With reference to  FIG.  1   , an example switch system  100  is illustrated. As shown, the switch system  100  may include a rotary switch  200  enclosed or otherwise supported by housing elements  104 . As shown, the switch system  100  may also include a plurality of electrical connections  102  (e.g., wires, wire harness, cables, etc.) configured to transmit electrical signals to the switch system  100  and/or receive electrical signals from the switch system  100 . Furthermore, the electrical connections  102  may be configured to supply power to the switch system  100  via providing electrical communication between the switch system  100  and an external power source (e.g., battery, wired power connection, etc.). 
     As shown, the switch system  100  may include a rotary switch  200  as described hereafter that is configured to rotate about an axis A. A rotary switch may refer to a mechanical or electronic switch that is operated by rotation (e.g., user inputted rotation or otherwise) in that the rotary switch  200  may be rotated about axis A to various positions. As described above, some vehicles (e.g., tractors, golf carts, lawn mowers, or the like) may use rotary switches as a mechanism for altering an operating state or function of the vehicle. By way of example, a vehicle may use a rotary switch to allow for changing of the vehicle&#39;s operating state (e.g., various speeds) and/or to adjust various vehicle functions (e.g., head light intensity, wiper speed, etc.). Although described herein with reference to a rotary switch and associated switch systems  100  implemented in vehicle applications, the present disclosure contemplates that the rotary switch features and configurations described herein may also be applicable to medical equipment, computing devices, industrial controls, consumer products, appliances, and/or the like. 
     Conventional rotary switches, however, rely on common contacts to facilitate electrical communication within the switch. For example, conventional rotary switch designs use rows of electrical contacts and dedicated common contacts that serve as shorted electrical commons. In operation, a commutator may move within the switch such that the commutator contacts an electrical contact and an electrical common (e.g., dedicated neutral contact). In this way, the electrical common only operates to close the circuit for the electrical contact (e.g., via the commutator). Given that each electrical contact and associated position within the rotary switch requires an associated common contact, electrical commons occupy additional space within a rotary switch (e.g., of a printed circuit board (PCB)) without providing increased functionality. As such, the switch systems  100  of the present application may employ rotary switch  200  configurations with resistor networks that allow for a commutator to electrically connect a pair of adjacent electrical contacts so as to modify an output voltage of the rotary switch corresponding to a position of the rotary switch without relying on electrical commons. In doing so, the rotary switch  200  of the present application as described hereafter may operate to (1) reduce material costs associated with printed circuit board (PCB) assemblies due to reduced electrical components (e.g., no electrical commons), (2) to increase space on PCB assemblies for other components, and/or (3) to increase the reliability of the rotary switch by reducing the number of components required for operation. 
     Rotary Switch 
     With reference to  FIG.  2   , an example rotary switch  200  is illustrated. As shown, the rotary switch  200  may include a substrate  202  supporting a plurality of electrical contacts  204 ,  208 . The substrate  202  may comprise a printed circuit board (PCB) configured to provide electrical communication to various electrical components (e.g., electrical contacts  204 ,  208 ) supported thereon. As would be evident to one of ordinary skill in the art in light of the present disclosure, the substrate  202  may be formed via any process for creating substrates or PCBs (e.g., subtractive processes, additive processes, semi-additive processes, chemical etching, copper patterning, lamination, plating and coating, or the like). Furthermore, while the substrate  202  is illustrated herein as having a substantially circular or disk shape, the present disclosure contemplates that the substrate  202  may be dimensioned (e.g., sized and shaped) for use in any switch system  100  regardless of geometric constraints. As described above, the substrate  202  may be configured to support and facilitate electrical communication between various electrical components (e.g., electrical contacts  204 , resistor network  205 , etc.) connected thereto. As such, the plurality of electrical contacts  204  and one or more of the resistors (not shown) described hereafter may be secured to the substrate  202  (e.g., via an adhesive, soldering, etc.). 
     With continued reference to  FIG.  2   , the rotary switch  200  may also include a plurality of electrical contacts  204 ,  208 . The electrical contacts  204 ,  208  may be formed of an electrically conductive material (e.g., gold alloy, silver alloy, conductive polymers, and/or other metals) such that, when contact is made with the electrical contact  204 ,  208 , electric current may be passed via this contact. When the electrical contacts  204 ,  208  touch (e.g., via contact or the like) the commutator  206 ,  210 , respectively, as described hereafter, electric current may pass via this contact. In some embodiments, the plurality of electrical contacts may be formed and/or positioned as a single set of electrical contacts (not shown) such that a single commutator may travel along the single set of electrical contacts. As illustrated in  FIG.  2   , however, in some embodiments, the plurality of electrical contacts may include a first set of electrical contacts  204  and a second set of electrical contacts  208  each with respective commutators  206 ,  210 . As described hereafter, a first commutator  206  may be configured to electrically connect pairs of adjacent electrical contacts of the first set of electrical contacts  204 . Similarly, a second commutator  210  may be configured to electrically connect pairs of adjacent electrical contacts of the second set of electrical contacts  208 . 
     In some embodiments, the substrate  202  may be formed as a disk or equivalent shape with circular cross-section. In such an embodiment, the disk (e.g., plate or the like) may define an opening  212  located at the center of the disk. As described above, by providing a rotary switch  200  without centrally located electrical commons as found in conventional rotary switches, the rotary switch  200  described herein may be formed of a substrate  202  with less material. In other embodiments, the rotary switch  200  may be formed as a solid disk (e.g., a single piece of material) such that the substrate  202  includes additional space for supporting other electrical components. In embodiments in which the substrate  202  is formed as a disk, the plurality of electrical contacts may be positioned along a peripheral edge of the disk so as to further provide increased space on the substrate  202  or allow for further substrate  202  material to be removed. 
     With continued reference to  FIG.  2   , the rotary switch  200  may include a resistor network (e.g., resistor network  205  in  FIG.  4   ) that is formed of a plurality of resistors (not shown) in electrical communication with the plurality of electrical contacts  204 ,  208 . As would be evident to one of ordinary skill in the art in light of the present disclosure, a resistor may refer to a passive electrical component that creates electrical resistance as a circuit element. The plurality of resistors (not shown) may be fixed resistors (e.g., lead arrangement, carbon pile, carbon film, thick or thin film, metal fil, wire wound, foil resistor, etc.) or variable resistors (e.g., resistance decade boxes, potentiometers, or the like). As illustrated in  FIG.  4    hereafter, the resistor network is configured to provide electrical communication between each of the electrical contacts within a set of electrical contacts  204 ,  208 . By way of example, each resistor of the resistor network (not shown) may be positioned so as to electrically connect a respective pair of adjacent electrical contacts  204 . For example, each electrical contact  204 , as described hereafter with reference to  FIG.  3   , may be connected to an adjacent electrical contact  204  via a resistor of the resistor network (not shown). Said differently, the plurality of resistors that form the resistor network (not shown) may be connected in series, each positioned between electrical contacts  204 . As described hereafter with reference to  FIG.  4   , each resistor in the resistor network (not shown) may include a resistance value that is different from resistance values of other resistors in the resistor network. 
     Reference hereafter is made to the first set of electrical contacts  204  and associated commutator  206 ; however, operation of the second commutator  210  and associated second set of electrical contacts  208  may operate substantially the same as the electrical contacts  204  and first commutator  206 . With reference to  FIG.  3   , the rotary switch  200  may further include a commutator  206  configured to move relative to the substrate  202  along the plurality of electrical contacts  204 . As shown, the commutator  206  is configured to electrically connect a pair of adjacent electrical contacts, for example a third contact  306  and a fourth contact  308 . As would be evident to one of ordinary skill in the art in light of the present disclosure, the plurality of electrical contacts  204  may be supported by the substrate  202  such that positions at which the location of the commutator  206  contacts adjacent electrical contacts  204  may be defined. In  FIG.  3   , for example, the substrate may support a first electrical contact  302 , a second electrical contact  304 , a third electrical contact  306 , a fourth electrical contact  308 , a fifth electrical contact  310 , a sixth electrical contact  312 , and a seventh electrical contact  314 . As such, a first position may refer to the position at which the commutator  206  contacts the first electrical contact  302  and the second electrical contact  304 , a second position may refer to the position at which the commutator  206  contacts the second electrical contact  304  and the third electrical contact  306 , etc. 
     As described hereafter with reference to  FIG.  4   , the resistor network (e.g., resistor network  205  in  FIG.  4   ) may be configured to electrically connect each of the electrical contacts  204  such that a resistor having a unique resistance value is positioned between adjacent electrical contacts  204 . Said differently, each position (e.g., position of the commutator  206 ) may be associated with a resistor that is bypassed by the commutator  206  such that the commutator  206  modifies an output voltage of the rotary switch  200  corresponding to a position of the rotary switch  200 . As shown in  FIG.  3   , the commutator  206  is located in the third position between the third electrical contact  306  and the fourth electrical contact  308 . As such, the resistor of the resistor network (not shown) associated with the third position is bypassed. Said differently, the commutator may operate as the path of least resistance for electric current supplied to the rotary switch  200  (i.e., the resistance value of the commutator  206  is less than the resistance value of each resistor of the resistor network). In this way, the commutator  206  may reduce the resistance of the electric current in the rotary switch  200  by an amount equivalent to the total resistance value of each resistor in the resistor network less the resistance value for the resistor located at the position of the commutator  206 . Given that Ohm&#39;s law states that the current through a conductor between two points is directly proportional to the voltage across the two points (V=IR), the voltage output by the rotary switch  200  may be modified by the change in resistance. 
     With reference to  FIG.  4   , an example circuit diagram of the rotary switch  200  and associated resistor network  205  is illustrated. As shown, the resistor network  205  may include a plurality of resistors connected in series between an input connection  402  and an output connection  404 . The resistor network  205  may include a first resistor R 1  having a first resistance value and positioned between the first electrical contact  302  and the second electrical contact  304 . The resistor network  205  may include a second resistor R 2  having a second resistance value and positioned between the second electrical contact  304  and the third electrical contact  306 . The resistor network  205  may include a third resistor R 3  having a third resistance value and positioned between the third electrical contact  306  and the fourth electrical contact  308 . The resistor network  205  may include a fourth resistor R 4  having a fourth resistance value and positioned between the fourth electrical contact  308  and the fifth electrical contact  310 . The resistor network  205  may include a fifth resistor R 5  having a fifth resistance value and positioned between the fifth electrical contact  310  and the sixth electrical contact  312 . The resistor network  205  may include a sixth resistor R 6  having a sixth resistance value and positioned between the sixth electrical contact  312  and the seventh electrical contact  314 . In such an example embodiment, the resistance values for each of R 1 , R 2 , R 3 , R 4 , R 5 , and R 6  are unique (e.g., different from one another). 
     In operation, the input connection  402  may receive an electric voltage having a defined voltage (e.g., 3.3 V). The output connection  404  may be connected to a ground resistor  207  so as to complete an electric circuit. In this example as illustrated in  FIG.  4   , the rotary switch  200  includes a single ground resistor  207  (e.g., resistor R 7 ). The resistor network  205  and ground resistor  207  form a voltage divider network. In an instance in which the commutator  206  fails to contact any adjacent pairs of electrical contacts, the resistance value for the resistor network is equivalent to the sum of each resistor (e.g., the sum of resistances of R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 ). As the commutator  206  moves along the plurality of electrical contacts  204 , however, the commutator  206  may electrically connect a pair of adjacent electrical contacts  204 . In doing so, the resistance value between the input connection  402  and the output connect  404  is reduced by the resistance value of the resistor located between the pair of adjacent electrical contacts  204 . 
     By way of a particular example, in an instance in which the resistor network  205  includes resistors R 1 , R 2 , R 3 , R 4 , R 5 , and R 6  having resistance values as illustrated in Table 1 below, the total resistance for the resistor network  205  prior to electrical connection by the commutator  206  is 21 kΩ. In an instance in which the commutator  206  is located at position three providing electrical connection between the third electrical contact  306  and the fourth electrical contact  308 , the total resistance for the resistor network  205  is reduced by the resistance value of the resistor between the third electrical contact  306  and the fourth electrical contact  308  (e.g., 3 kΩ). Said differently, the electric current received by rotary switch  200  bypasses the resistor located at position  3 . As shown in Table 1, the resistance value between the input connection  402  and the output connection  404  is therefore 18 kΩ. By way of a further example, in an instance in which the input connection  402  receives 3.3 V, the output voltage of at the output connection  402  may be modified to approximately 1.179 V. Although described herein with reference to a rotary switch  200  having seven (7) electrical contacts  204  and, by association, a resistor network including six (6) resistors, the present disclosure contemplates that the rotary switch  200  may include any number of electrical contacts  204  and associated resistors based upon the intended application of the rotary switch  200 . 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Example voltage output based on commutator position. 
               
            
           
           
               
               
               
               
            
               
                   
                 Resistor  
                 Resistance  
                 Voltage 
               
               
                 Commutator  
                 Resistance 
                 value between  
                 at 
               
               
                 Position 
                 Value 
                 Input and Output 
                 Output 
               
               
                   
               
            
           
           
               
               
               
               
            
               
                 1 
                 1 kΩ 
                 20 kΩ 
                 1.100 V 
               
               
                 2 
                 2 kΩ 
                 19 kΩ 
                 1.138 V 
               
               
                 3 
                 3 kΩ 
                 18 kΩ 
                 1.179 V 
               
               
                 4 
                 4 kΩ 
                 17 kΩ 
                 1.222 V 
               
               
                 5 
                 5 kΩ 
                 16 kΩ 
                 1.269 V 
               
               
                 6 
                 6 kΩ 
                 15 kΩ 
                 1.320 V 
               
               
                   
               
            
           
         
       
     
     With continued reference to  FIG.  4   , in some embodiments, the rotary switch  200  may include a microcontroller  406  configured to receive a voltage output from the output connection  404  and determine the rotational position (e.g., degrees, radians, relative positioning, etc.) of the rotary switch  200 . In order to determine the rotational position, the microcontroller  406  may be embodied in any number of different ways and may, for example, include one or more processing devices configured to perform independently. By way of example, the microcontroller may be configured to execute instructions stored in a memory or otherwise accessible to one or more processors of the microcontroller  406 . Alternatively or additionally, the microcontroller  406  may be configured to execute hard-coded functionality. As such, whether configured by hardware or by a combination of hardware with software, the microcontroller  406  may represent an entity (e.g., physically embodied in circuitry) capable of performing operations according to an embodiment of the present invention while configured accordingly. In some embodiments, the rotary switch  200  may further include a level shifted instrumentation amplifier or equivalent circuitry, housed by the rotary switch  200 , the microcontroller  406 , or the like, to facilitate conversion of the output voltage from the rotary switch  200  to a corresponding position of the rotary switch  200 . In some embodiments, the rotary switch  200  may comprise the microcontroller and amplifier circuitry, while in other embodiments, the microcontroller  406  and/or the level shifted instrumentation amplifier may be housed separate from the rotary switch  200 . 
     Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.