Abstract:
A direct current driver circuit for driving a modulated direct current is disclosed. The direct current driver circuit uses a switched capacitor network to keep the circuit operating within carefully prescribed voltage levels in order to reduce energy losses.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to and the benefit of U.S. Provisional Application No. 62/267,852 filed Dec. 15, 2015, which is incorporated herein by reference in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The disclosure relates to the field of electronic circuits for driving modulated direct current particular, but not by way of limitation, the discussion discloses techniques for modulating direct current with zero voltage switching and switched capacitor modulation. 
       BACKGROUND 
       [0003]    Direct current (DC) loops are a type of electronic circuitry that provides certain advantages for many applications. Most digital electronic circuits operate with direct current circuits. With a modulated direct current loop, many independent individual direct current circuits can be supported. However, the field of electronic circuitry for generating modulated direct current loops is rather limited. Thus, it would be desirable to develop new and improved electronic circuitry for generating modulated direct current loops. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0004]    In the drawings, which are not necessarily drawn to scale, like numerals describe substantially similar components throughout the several views. Like numerals having different letter suffixes represent different instances of substantially similar components. The drawings illustrate generally, by way of example, but not by way of lip various embodiments discussed in the present document. 
           [0005]      FIG. 1  illustrates a diagrammatic representation of a machine in the example form of a computer system within which a set of instructions, for causing the machine to perform any one or more of the methodologies discussed herein, may be executed. 
           [0006]      FIG. 2  illustrates a block diagram of the overall architecture of a single-wire multiple-node direct current loop control system. 
           [0007]      FIG. 3  illustrates a timing diagram that shows show digital information may be modulated as current deviations from a nominal current value. 
           [0008]      FIG. 4  illustrates a direct current driver circuit that may include a switched capacitor network. 
           [0009]      FIG. 5A  illustrates a first embodiment of a switched capacitor network. 
           [0010]      FIG. 5B  illustrates a second embodiment of a switched capacitor network. 
           [0011]      FIG. 5C  illustrates a first embodiment of a switched capacitor network. 
           [0012]      FIG. 6  illustrates a direct current driver circuit that includes a switched capacitor network to manage voltage levels. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0013]    The following detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show illustrations in accordance with example embodiments. These embodiments, which are also referred to herein as “examples,” are described in enough detail to enable those skilled in the art to practice the invention. It will be apparent to one skilled in the art that specific details in the example embodiments are not required in order to practice the present invention. For example, although the example embodiments are mainly disclosed with reference to a system at efficiently transmits energy and control information to control Light Emitting Diodes (LEDs), the teachings of this disclosure can be used in any current loop circuit system. The example embodiments may be combined, other embodiments may be utilized, or structural, logical and electrical changes may be made without departing from the scope what is claimed. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope is defined by the appended claims and their equivalents. 
         [0014]    In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one. In this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated. Furthermore, all publications, patents, and patent documents referred to in this document are incorporated by reference herein in their entirety, as though individually incorporated by reference. In the event of inconsistent usages between this document and those documents so incorporated by reference, the usage in the incorporated reference(s) should be considered supplementary to that of this document; for irreconcilable inconsistencies, the usage in this document controls. 
       Computer Systems 
       [0015]    The present disclosure concerns computer systems since computer systems are generally used to control LED lighting and display systems.  FIG. 1  illustrates diagrammatic representation of a machine in the example form of a computer system  100  that may be used to implement portions of the present disclosure. Within computer system  100  there are a set of instructions  124  that may be executed for causing the machine to perform any one or more of the methodologies discussed herein. In a networked deployment, the machine may operate in the capacity of a server machine or a client machine in client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. The machine may be a personal computer (PC), a tablet PC, a set-top box (STB), a Personal Digital Assistant (PDA), a cellular telephone, a web appliance, a network router, switch or bridge, or any machine capable of executing a set of computer instructions (sequential or otherwise) that specify actions to be taken by that machine. Furthermore, while only a single machine is illustrated, the term “machine” shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein. 
         [0016]    The example computer system  100  includes a processor  102  (e.g., a central processing unit (CPU), a graphics processing unit (GPU) or both), a main memory  104  and a static memory  106 , which communicate with each other via a bus  108 . The computer system  100  may further include a video display adapter  110  that drives a video display system  115  such as a Liquid Crystal Display (LCD) or a Cathode Ray Tube (CRT). The computer system  100  also includes an alphanumeric input device  112  (e.g., a keyboard), a cursor control device  114  (e.g., a mouse or trackball), a disk drive unit  116 , an output signal generation device  118 , and a network interface device  120 . 
         [0017]    The disk drive unit  116  includes a machine-readable medium  122  on which is stored one or more sets of computer instructions and data structures (e.g., instructions  124  also known as ‘software’) embodying or utilized by any one or more of the methodologies or functions described herein. The instructions  124  may also reside, completely or at least partially, within the main memory  104  and/or within the processor  102  during execution thereof by the computer system  100 , the main memory  104  and the processor  102  also constituting machine-readable media. Note that the example computer system  100  illustrates only one possible example and that other computers may not have all of the components illustrated in  FIG. 1 . 
         [0018]    The instructions  124  may further be transmitted or received over a computer network  126  via the network interface device  120 . Such transmissions may occur utilizing any one of a number of well-known transfer protocols such as the File Transport Protocol (FTP). 
         [0019]    While the machine-readable medium  122  is shown in an example embodiment to be a single medium, the term “machine-readable medium” should be taken to include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) that store the one or more sets of instructions. The term “machine-readable medium” shall also be taken to include any medium that is capable of storing, encoding or carrying a set of instructions for execution by the machine and that cause the machine to perform any one or more of the methodologies described herein, or that is capable of storing, encoding or carrying data structures utilized by or associated with such a set of instructions. The term “machine-readable medium” shall accordingly be taken to include, but not be limited to, solid-state memories, optical media, and magnetic media. 
         [0020]    For the purposes of this specification, the term “module” includes an identifiable portion of code, computational or executable instructions, data, or computational object to achieve a particular function, operation, processing, or procedure. A module need not be implemented in software; a module may be implemented in software, hardware/circuitry, or a combination of software and hardware. 
         [0021]    In the present disclosure, a computer system may comprise a very small microcontroller system. A microcontroller may comprise a single integrated circuit that contains the four main components that create a computer system: an arithmetic and logic unit (ALU), a control unit, a memory system, and an input and output system (collectively termed I/O). 
         [0022]    Microcontrollers are very small and inexpensive integrated circuits that are very often used in digital electronic devices. 
       Multiple-Node Power and Control System Overview 
       [0023]    To power and control multiple circuit nodes, a single-wire direct current loop control system may be used. Specifically, individually circuit nodes are arranged in a series configuration that is driven by a head-end control unit located at the head of the series. The series of separate individually controlled circuit nodes may be referred to as a “line” or “string” of nodes devices. The head-end control unit for the string of nodes may be referred to as the “line driver” or “string driver” since the head-end control unit provides the electrical power and control signals that drive all of the individually controlled circuit nodes on the line or string. 
         [0024]    Although the present disclosure will be disclosed with circuit nodes for driving Light Emitting Diodes (LEDs), the teachings of the present disclosure may be used to control circuit nodes driving any other type of electronic circuits such as sound systems, motors, sensors, cameras, Liquid Crystal Displays (LCDs), etc. 
         [0025]      FIG. 2  illustrates a block diagram of the overall architecture of the single-wire direct current loop control system that drives several circuit node units ( 250 - 1  to  250 -N). 
         [0026]    Specifically, a line driver circuit  220  is situated at the head of a series of individually controlled circuit node units ( 250 - 1  to  250 -N). In the particular embodiment of  FIG. 2 , each of the individually controlled circuit node units ( 250 - 1  to  250 -N) are used to drive Light Emitting Diodes (LEDs). Since this specific application is for driving LEDs, the line driver circuit  220  is referred to as the LED line driver circuit  220 . But as stated earlier, the line driver circuit  220  can be used to drive any other type of electrical circuit. 
         [0027]    In the embodiment of  FIG. 2 , the LED line driver circuit  220  receives electrical power from an external power supply circuit  210 . The LED line driver circuit  220  also receives LED control data from a master LED controller system  230 . The master LED controller system  230  provides detailed control data describing how the various LEDs on the individually controlled LED units ( 250 - 1  to  250 -N) on the string should be powered on or off and the brightness of each powered on LED. The master LED controller system  230  can be any type of digital electronic system that provides LED control data the appropriate format to the LED line driver circuit  220 . 
         [0028]    The master LED controller system  230  may range from a simple single chip microcontroller to a sophisticated computer system that drives many different LED strings in a coordinated manner. For example, in a relatively simple embodiment, the nit components of a microcontroller-implemented master LED controller system  230 , the power supply  210 , and the LED line driver  220  may be combined into a single small LED Driver System  239  that controls an entire long string of LED units  250 . In a more sophisticated embodiment, an external computer system, such as computer system  100  illustrated in  FIG. 1 , can be programmed to output appropriate LED control data signals  231  to the LED line driver circuit  220  using signal generation device  118  or any other appropriate data output system. 
         [0029]    It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.