Decorative light string with a screw head

A light string with a screw head is provided, including a light string and a screw head. The light string includes a plurality of LEDs connected in series by a plurality of wires. The wires connected to the screw head. The screw head further includes an insulating body, a screw shell and a contacting end. The insulating body further includes a circuit to regulate the current before providing to the LEDs. The light string with a screw head of the present invention can be used with conventional light string to extend the use of the conventional light string and provide more varieties for decorative and lighting purposes.

FIELD OF THE INVENTION

The present invention generally relates to a light string, and more specifically to a light string with a screw head able to draw power from a conventional socket for a screw-on light bulb.

BACKGROUND OF THE INVENTION

The LED provides many advantages over the conventional tungsten light bulb, such as longer life span, power efficiency, durability, reliability, smaller size, and shorter reaction time, and so on. The LED has been widely used in decorative light string, especially with the recent choices of color varieties. However, conventional LED light strings are seldom compatible with the other types of light strings in terms of the voltage, current and the electrical connections. To improve the usability of the LED light string, it is imperative to develop LED light strings that can be used in conjunctions with conventional tungsten light-bulb light strings.

The conventional light strings made with larger tungsten light bulbs are brighter and popular among many consumers. Each tungsten light bulb is with a screw head to screw on the sockets in the light string. The advantage is that each light bulb can be replaced when necessary. The present invention is designed to be compatible with the light bulb with a crew head. In other words, the light string of the present invention can be used to replace the tungsten light bulb with screw head to provide the conventional light strings more varieties of decorative choices.

SUMMARY OF THE INVENTION

The primary object of the present invention is to provide a light string that can be used with the conventional light strings, including a plurality of LED lights strung together with a screw head on one end of the string. The screw head matches the conventional socket for tungsten light bulbs used in a light string. Therefore, the light string of the present invention can be used to replace a tungsten light bulb to provide additional decorative choice to the conventional light string with tungsten light bulbs. In addition, the light string of the present invention can help to simplify the wiring of the light string.

Another object of the present invention is to provide a light string with screw head that is safe to use with the conventional light string. The light string of the present invention includes a well-hidden circuit for controlling the voltage of the current, and a fuse is also included to guarantee the safety of use in case of overloading. The light string can be varied to become fish-net, curtain type or other three dimensional decoration item. Additional control box can be included to control the lighting, such as blinking, light intensity change, for various lighting and decorative purposes and occasions.

To achieve the aforementioned objects, the present invention provides a light string with a screw head. The screw head includes an insulating body, a screw shell, and a contacting end. The inside of the insulating body includes a circuit to regulate the input alternating current to a pre-determined direct current to drive the LED light string. The screw shell can be used in a conventional light bulb socket so that the contacting end is electronically connected to the input alternating current power source.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1shows a three-dimensional schematic view of the present invention. The present invention includes a light string1and a screw head2. Light string1includes a plurality of LEDs11. Each LED11is connected in series by at least two wires12. Wires12are connected to screw head2. Screw head2includes an insulating body21, a metal screw shell22and a contacting end23. Contacting end23is not directly in contact with screw shell22, which is the standard screw head design. The size of the screw head can be varied to match the different sizes of the standard socket. The inside of insulating body21includes a circuit. The input ends of the circuit are connected to the inner wall of screw shell22and contacting end23, respectively. Inside of insulating body21is the insulating, thermal-endurable, and non-flammable material to seal the circuit for water-proof. Therefore, light string1can be used for outdoor conditions. The shape of insulting body21is not limited to any specific shape. Wires12are connected to the output ends of the circuit inside insulting body21. The circuit is for regulating the current and lowering the voltage so that the alternating current from the input ends can be transformed to the low voltage direct current that is suitable for LED. The present invention uses screw head2to draw power from conventional light-bulb socket. Therefore, the present invention can extend the usage of the conventional light string, and provide more varieties for lighting and decorative purposes.

As the current from the conventional light-bulb socket from the conventional light string is alternating current, and the LED uses low-voltage direct current, the circuit inside insulating body21of screw head2of the present invention must regulate the current and lower the voltage. There are many ways to implement the circuit. The present invention describes a few embodiments for explanation, but the scope of the present invention is not limited to the embodiments described here.FIG. 2shows a schematic view of the first embodiment of the circuit of the present invention. As shown inFIG. 2, circuit24includes a regulating circuit240formed by a plurality of diodes. The alternating current drawn from input ends241is transformed into direct current. If the number of LEDs246is small, the large current may damage LEDs246. It is, therefore, preferably to have more than 50 LEDs246in a light string of the present invention. In other words, screw head2is preferably connected to a light string with at least 50 LEDs. To further improve the safety, a fuse243may be included close to input ends241to open the circuit when the circuit is overloaded.

FIG. 3shows a schematic view of the second embodiment of the circuit of the present invention. As shown inFIG. 3, when the number of LEDs246is less than 5, circuit24further includes a first auxiliary circuit244and a second auxiliary circuit245in addition to regulating circuit240. First auxiliary circuit244is a filter circuit, and is connected in series with input end241, and second auxiliary circuit245is a resistor, and is connected in series with one of output ends242. The resistance of the resistor must match the number of LEDs246so that circuit24can lower the current supply to the light string with less than 50 LEDs.

FIG. 4shows a schematic view of the application of the present invention. As shown inFIG. 4, string light1can use screw head2to screw into light-bulb socket41of conventional light string4. By screwing off a light-bulb from light-bulb socket41and screwing screw head2into light-bulb socket41, an LED light string of the present invention can be used to replace a light bulb in a conventional light string and extend the use of the conventional light string.FIG. 4only depicts an embodiment of light-bulb socket41. The shape of light-bulb socket41can have different shape or sizes, and screw head2can be made to match the shape and the size of light-bulb socket41. Similarly, the circuit inside the screw head may also have a different implementation due to the different voltage in different areas of the world.

FIG. 5shows another application of the present invention. This embodiment uses a larger conventional light seat5with a screw socket51at the top for screw head2of the present invention to screw into. As the output voltage is higher in this type of light seat, the circuit inside screw head2must also be adjusted to take this into account in order to transform the alternating current into the appropriate direct current for the LEDs. Therefore, the light string of the present invention can be used with any type of conventional light seat with a screw socket.

FIG. 6shows another embodiment of the present invention. In this embodiment, wire12connected to screw head2is connected to a control box6. Control box6includes a plurality of wires12extending to connect LEDs11. When in use, screw head2draws on the power from the conventional light-bulb socket, and control box6can be designed to control the lighting of the LEDs, such as blinking, dimming, and other effects.

FIG. 7shows yet another embodiment of the present invention. In this embodiment, light string1can be assembled into various shapes, such as drape1A, fish net1B, or a wrapping around an object7, such as a star1C. Object7is not limited to any specific shape.

FIG. 8shows a light string of the present invention used in a Xmas tree. As shown inFIG. 8, a Xmas tree9is decorated with a conventional light string4. To further improve the decorative effects, the user can replace some light bulbs in conventional light string4with the light string of the present invention.

In summary, the light string of the present invention includes a screw head that can be used to draw power from a light-bulb socket in a conventional light string, and can be used with conventional light strings to improve decorative effects.