Patent Publication Number: US-10314127-B2

Title: Parallel-type light string

Description:
FIELD OF THE DISCLOSURE 
     The disclosure particularly relates to a new parallel-type light string. 
     BACKGROUND 
     As to a traditional parallel-type LED light string, positive and negative electrodes of a power supply both are connected to the first LED unit of the light string, because of the problem of voltage drop, the LED unit at the front of the light string and near power supply wires are relatively bright, the more backward in position of the LED unit, the darker the LED unit is, and when the number of the LED unit is more than 30, the brightnesses at the front and at the rear of the light string will be very different. If a supply voltage is attempted to be increased for the purpose of solving the problem of voltage drop, the LED unit at the most front of the light string will be burned out soon. 
     In another aspect, a “DCTD-protocol based LED” is also called as a “LED equipped with IC chip” and may be a monochromatic LED equipped with IC chip, a RGB LED equipped with IC chip or a W+RGB LED equipped with IC chip. 
     SUMMARY 
     An objective of the disclosure is to provide a new parallel-type LED light string with simple production process, uniform brightness and independently workable LED units, so as to solve the problem in the prior art. 
     In order to achieve the objective, the disclosure provides the following technical solutions. 
     I In particular, a new parallel-type LED light string includes multiple LED units connected in parallel to form a light string; the LED units are electrically connected to a first conductive wire and a second conductive wire, each of the LED units includes a first end and a second end, one end of the first conductive wire is connected to the first end of a first one of the LED units, and one end of the second conductive wire is connected to the second end of a last one of the LED units. 
     In an embodiment, each of the LED units includes one forward LED and one backward LED connected in parallel, and the other ends of the first conductive wire and the second conductive wire are connected to a light string controller. 
     In an embodiment, the light string includes DCTD-protocol based LEDs, the LED units and the DCTD-protocol based LEDs are alternately disposed and connected in parallel in the light string; and the other ends of the first conductive wire and the second conductive wire are connected to a DCTD-protocol based controller. 
     In an embodiment, the light string is a linear light string, a circular light string, or a semicircular light string. 
     The efficacy of the disclosure are that: 
     in one aspect, as to the LED equipped with IC chip: a DCTD-protocol based controller with a DCTD (DC Wire Transmit Data) protocol configured therein superimposes transmission slot pulse signals and delivers them to LEDs with respective decoding ICs through two power supply wires and thereby controls the changes of light colors and patterns of the LEDs while without affecting other common LED units, so that functions and patterns of the light string become more while only two wires are required; as a result, compared with other way of achieving the same function and effect, it requires less material as well as less manpower; 
     in another aspect, multiple LED units are connected in parallel to form the light string and a wire connection mode is that: the first conductive wire and the second conductive wire are respectively connected to the first one LED unit and the last one LED unit, so that voltages and currents of the respective LED units of the entire light string are consistent and thus uniform brightness is achieved, and moreover the number of 1-N LED units can be determined according to power of a power supply; and 
     in still another aspect, for such parallel-type LED light string, it is better than a serial-type LED light string (when the number of serially-connected LED units in the serial-type LED light string is more than 50, the light units respectively at the front and at the rear will have a more significant difference in brightness, and when one LED unit in a group is abnormal, the whole group does not light up), and in particular one abnormal LED unit in the parallel-type light string would not affect the other LED units, the production process is simple, the production cost is low and it is more suitable for decorative LED light string. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of a first embodiment of a new parallel-type light string. 
         FIG. 2  is a schematic view of a second embodiment of a new parallel-type light string. 
         FIG. 3  is a schematic view of a third embodiment of a new parallel-type light string. 
         FIG. 4  is a schematic view of a shape of a new parallel-type light string. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     In the following, technical solutions in embodiment of the disclosure will be described clearly and completely in accordance with the drawings in the embodiments of the disclosure. 
     Please referring to  FIG. 1 , in a first embodiment of the disclosure, a new parallel-type light string includes multiple (i.e., more than one) LED units  1  connected in parallel to form a light string. The LED units  1  are electrically connected to a first conductive wire  2  and a second conductive wire  3 . Each of the LED units  1  includes a first end and a second end. One end of the first conductive wire  2  is connected to the first end of the first one of the LED units  1 , and one end of the second conductive wire  3  is connected to the second end of the last one of the LED units  1 . Each of LED units  1  includes two individual light emitting diodes i.e., a forward LED and a backward LED, connected in parallel (between the first end and the second end). The other ends of the first conductive wire  2  and the second conductive wire  3  are connected to a light string controller  4 . The light string controller  4  may control DC positive electrode and negative electrode to repeatedly alternate, so that displays and flickers of the LED units are diversified. 
     Please referring to  FIG. 2 , in a second embodiment of the disclosure, a difference from the first embodiment is that: the light string includes DCTD-protocol based LEDs  6 , the LED units  1  and the DCTD-protocol based LEDs  6  are alternately disposed and connected in parallel in the light string, and the other ends of the first conductive wire  2  and the second conductive wire  3  are connected to a DCTD-protocol based controller  5 . The DCTD-protocol based controller  5  only controls the DCTD-protocol based LEDs  6 . 
     Please referring to  FIG. 3 , in a third embodiment of the disclosure, a difference from the first embodiment is that: the LED units  1  each are a single light emitting diode, the first conductive wire  2  and second conductive wire  3  are directly connected to a direct current (DC) power supply. The first conductive wire  2  is connected to a positive electrode of the direct current power supply, and the second conductive wire  3  is connected to a negative electrode of the direct current power supply. 
     In the above embodiments, the light string may be arranged into a variety of shapes such as: a linear light string, a circular light string, a semicircular light string (as show in  FIG. 4 ) and so on. 
     For one skilled in the art, apparently, the disclosure is not limited to the details of the foregoing exemplary embodiments, under the prerequisite of without departing from the spirit or essential characteristics of the disclosure, other specific forms may be used to achieve the disclosure. Therefore, no matter from what point of view, the described embodiments should be considered as illustrative and not restrictive, the scope of the disclosure is defined by the appended claims rather than by the foregoing description and thus is intended to encompass meanings of equivalent elements within the claims and all changes within the scope of the claims. Any reference numerals of accompanying drawings involved in the claims should not be construed as limiting the related claims. 
     In addition, it should be understood that although the specification is described in terms of the embodiments, not every embodiment includes only one independent technical solution. This description of the specification is merely for the sake of clarity and one person skilled in the art should take the specification as a whole. The technical solutions of the respective described embodiments can also be appropriately combined to form other embodiments that can be understood by one skilled in the art.