Patent Publication Number: US-2017350578-A1

Title: Light emitting diode lamp

Description:
BACKGROUND 
     Technical Field 
     The present disclosure relates to a light emitting diode (LED) lamp. More particularly, the present disclosure relates to an LED lamp which is used for replacing the high-pressure sodium lamp. 
     Description of Related Art 
     A sodium lamp is a gas-discharge lamp that uses sodium in an excited state to produce light. There are two varieties of such lamps: low pressure and high pressure. Low-pressure sodium lamps only give monochromatic yellow light, but their yellow light restricts applications to outdoor lighting such as street lamps. High-pressure sodium lamps have a broader spectrum of light than the low-pressure lamps. They have been widely used for outdoor area lighting such as streetlights, freeway, airport, wharf, dock, railroad station, plaza, mining industry, park and courtyard. They are also common used as plant grow lights. 
     The high-pressure sodium light has advantages of allowing the light penetrate fog and rain with minimum of dispersion, and is less attractive to insects. However, the high-pressure sodium light is bulky, low luminous efficiency, and slow response time, and cannot provide a proper visible environment for driver since poorer color rendering than other types of lamps (such as LED lamps). 
     SUMMARY 
     According to one aspect of the present disclosure, a light emitting diode lamp connectable to a socket holder of a power conversion device includes a lamp shell, a socket, and an LED module. The socket and the LED module are respectively assembled with the lamp shell. The LED module includes a circuit board, a plurality of LEDs, and an electronic circuit. The circuit board is provided with conductive traces on a surface thereof. The LEDs are mounted on the other surface of the circuit board and electrically connected to the conductive traces. The electronic circuit is mounted on the surface mounted with the LEDs and electrically connected to the conductive traces. The LEDs arranged at a center of the circuit board and surrounded with the electronic circuit are electrically connected to the electronic circuit via the conductive traces, and the electronic circuit is electrically connected to the socket for receiving electric power required by the LEDs. 
     In an embodiment of the present disclosure, at least one penetrating hole is formed on the circuit board, and the penetrating hole is applied to fasten the circuit board on the lamp shell. 
     In an embodiment of the present disclosure, the LED lamp further comprises an enclosure assembled with the lamp shell and encloses the LED module. 
     In an embodiment of the present disclosure, the electronic circuit comprising an input terminal, a rectifying unit, a filtering unit, and an output terminal. The input terminal is electrically connected to the socket. The rectifying unit is electrically connected to the input terminal and configured to converting an electric power entering the rectifying unit into a direct current (DC) electric power. The filtering unit is electrically connected to the rectifying unit and configured to filter ripple existing in the DC electric power. The output terminal is electrically connected to the filtering unit and the LEDs, and the LEDs are driven to light by the DC electric power which the ripple is filtered. 
     In an embodiment of the present disclosure, the rectifying unit comprising a plurality of rectifying diodes electrically connected to each other. 
     In an embodiment of the present disclosure, the filtering unit is a capacitor. 
     In an embodiment of the present disclosure, the power conversion device comprising a transformer and a current-limiting unit electrically connected to an output of the transformer, and an output of the current-limiting unit is electrically connected to the socket. 
    
    
     
       BRIEF DESCRIPTION OF DRAWING 
       The present disclosure can be more fully understood by reading the following detailed description of the embodiment, with reference made to the accompanying drawings as follows: 
         FIG. 1  is a top view of a light emitting diode (LED) module according to the present disclosure; 
         FIG. 2  is a circuit diagram of the LED module according to the present disclosure; 
         FIG. 3  is a schematic view of a LED lamp and a power conversion device according to the present disclosure; and 
         FIG. 4  is a circuit diagram of the LED lamp and the power conversion module according to the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     A preferred embodiment of the present disclosure will be described with reference to the drawings. 
     Reference is made to  FIG. 1 , which is a top view of a light emitting diode (LED) module of the present disclosure. In  FIG. 1 , the LED device  10  includes a circuit board  1 , a plurality of light emitting diodes (LEDs)  2 , and an electronic circuit  3 . The circuit board  1  is provided with conductive traces (not shown); the conductive traces are placed on a surface of the circuit board  1 . The circuit board  1  is further provided with at least one penetrating holes  11  applied to fasten the circuit board  1  on the lamp shell (not shown). The LEDs  2  and a plurality of electronic components  321  and  331  of the electronic circuit  3  are mounted on the other surface of the circuit board  1 , and the LEDs  2  and the electronic components  321  and  331  are electrically connected to the conductive traces. Specifically, the terminals (not shown) of the LEDs  2  and the electronic components  321  and  331  are respectively penetrated the circuit board  1  and connected to the conductive traces, thus the LEDs  2  can be electrically connected to the electronic components  321  and  331  by the conductive traces. The electronic components  321  and  331  are further electrically connected to a socket (not shown) assembled with the lamp shell for receiving an electric power required by the LEDs  2 . 
     Furthermore, the LEDs  2  are arranged at the center of the surface of the circuit board  1 . The electronic components  321  and  331  surrounds the LEDs  2 , as such light emitted from the LEDs cannot shield by the electronic components  321  and  331 . 
     Reference is made to  FIG. 2 , which is a circuit diagram of the LED module according to the present disclosure. The electronic circuit  3  includes an input terminal  31 , a rectifying unit  32 , a filtering unit  33 , and an output terminal  34 . 
     The input terminal  31  is electrically connected to the socket of the LED lamp. 
     The rectifying unit  32  is electrically connected to the input terminal  31  and configured to convert an electric power (such as an alternative current (AC) electric power) into a pulsating direct current (DC) electric power. The rectifying unit  32  includes a plurality of electronic components  321  electrically connected to each other, and the electronic components  321  are, for example, rectifying diodes. 
     The filtering unit  33  is electrically connected to the rectifying unit  32  and configured to remove the unwanted AC components (called ripple) of the rectifying unit  32  output, thus the filtering unit  22  can output a smooth and steady DC electric power. In  FIG. 2 , the filtering unit  33  includes the electronic component  331 , and the electrical component  331  is, for example, a capacitor  331 . 
     The output terminal  34  is electrically to the filtering unit  33  and the LEDs  2 , and the LEDs  2  are driven to light by the smooth and steady DC electric power outputted from the filtering unit  22 . 
     Reference is made to  FIG. 3  and  FIG. 4 .  FIG. 3  is a schematic view of a LED lamp and a power conversion device according to the present disclosure;  FIG. 4  is a circuit diagram of the LED lamp and the power conversion device according to the present disclosure. The LED module  10  is assembled with a lamp shell  20 . The lamp shell  20  is further assembled with a socket (such as E40 socket)  201 , wherein the LED module  10  and the socket  201  are arranged at opposite sides of the lamp shell  20 . An enclosure  202  is further assembled with the lamp shell  20  and encloses the LED module  10 . Thus an LED lamp is formed. In operation, the LED lamp is adapted to the power conversion device  30  used to provide electric power to conventional high-pressure sodium lamp. The power conversion device  30  includes a transformer  301  and a current-limiting unit  302 , and a socket adaptor  303 ; the current-limiting unit  302  is arranged between the transformer  301  and the socket adapter  303  and electrically connected thereto. The current-limiting unit  302  is configured to limit the current transmitted to the LEDs  2  for preventing the LEDs from over-current damage. 
     In operation, the socket  201  assembled with the lamp shell  20  of the LED lamp is installed in the socket holder  303  of the power conversion module  20 . An AC electric power enters the power conversion module  30  is converted by the transformer  310  and the current-limiting unit  302  accordingly, and then transmitted to the socket holder  303 . The AC electric power enters to the LED lamp thereafter. The AC electric power entering the LED lamp is first transmitted to the rectifying unit  32 ; the rectified unit  32  converts the AC electric power provided by the power conversion module  30  into the pulsating DC electric power, and the pulsating DC electric power is then transmitted to the filtering unit  33 . The rectifying unit  33  removes the ripple of the pulsating DC electric power, and output the smooth and steady DC electric power to the LEDs  2  for driving the LEDs  2  to light. 
     When the LED lamp  20  is failure or damage, the LED lamp  20 , a user can individually replace the LED lamp  20  by screwing the socket  201  from the socket holder  303  and install another LED lamp  20  onto the power conversion module  30 . 
     Although the present disclosure has been described with reference to the foregoing preferred embodiment, it will be understood that the disclosure is not limited to the details thereof. Various equivalent variations and modifications can still occur to those skilled in this art in view of the teachings of the present disclosure. Thus, all such variations and equivalent modifications are also embraced within the scope of the disclosure as defined in the appended claims.