Patent Application
20130076256
1. Field of the Invention
The invention relates to a decorative light string, and more particularly to a decorative light string that is able to provide variable lighting effects without using a control box.
2. Description of Related Art
With reference to
The power plug 51 is adapted to connect to an AC power source to receive AC voltage.
The control box 52 is connected to the power plug to receive the AC voltage and has a circuit module for converting the AC voltage to DC voltage and outputting control signals to activate the lighting units 54. The control box 52 provides five wires, wherein three of them are connected to the lighting units 54 and others are connected to the tail socket 53.
The tail socket 53 is to be connected to a power plug 51 of another light string thus connecting different light strings in series to expand the number of the lighting units 54.
To control the lighting units 54 to generate different decorative effects, the control box 52 is an essential apparatus. However, the control box 52 will increase the complexity and the fabricating cost of the light string.
A main objective of the present invention is to provide a light string that provides variable lighting effects without using a control box to simplify the structure of the light string and reduce the manufacturing cost.
The light string in accordance with the present invention includes a plug, a tail socket and multiple LED lamps connected between the plug and the tail socket. The plug and tail socket respectively have a voltage converting circuit to commonly form a power converting circuit that converts AC voltage to DC voltage. The LED lamps include a primary LED lamp and multiple secondary LED lamps, wherein the primary LED lamp has a primary control chip for outputting control data to each LED lamp through a signal wire. The LED lamps receive the DC voltage and are connected in sequence by the signal wire. Therefore, the LED lamps are able to generate different lighting effects according to the received control data without using an additional control box.
Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
With reference to
One of the LED lamps is designated as a primary LED lamp 30a and others are secondary LED lamps 30b. The circuit module 31a of the primary LED lamps 30a is different from other circuit modules 31b of the secondary LED lamps 30b. As shown in
The primary control chip 32 has a data output terminal (DO) and outputs control data from the output terminal (DO). Each secondary control chip 33a, 33b has a data input terminal (DI) and a data output terminal (DO). The data input terminal (DI) of a secondary control chip 33b is connected to the data output terminal (DO) of the primary control chip 32 or a previous secondary control chip 33a, 33b. Therefore, the primary control chip 32 and the secondary control chips 33a, 33b are sequentially connected. The primary control chip 32 will outputs a command to all secondary control chips 33a, 33b to sequentially and respectively designate the addresses. For example, the addresses of the control chips 33a, 33b can be 0001, 0002, 0003 . . . etc.
The LEDs 34 are connected to and controlled by the secondary control chips 33a, 33b based on the received control data from the primary control chip 32 to generate variable effects. For example, the LEDs 34 can emit light in different colors and produce a particular color by color mixing. The LEDs 34 also can be selectively or intermittently activated to generate twinkle effects. The activation of the LEDs 34 may be synchronous or asynchronous depending on the control data from the primary control chip 32.
With further reference to
The light string in accordance with the present invention only uses four wires 41-44 to transmit power and control data between the plug 10, the tail socket 20 and the LED lamps 30a, 30b. The four wires consist of a first AC wire 41, a second AC wire 42, a DC wire 43 and a signal wire 44. The first and second AC wires 41, 42 extend from the plug 10 to the tail socket 20 for transmitting AC voltage to a subsequent light string connected to the tail socket 20. The DC wire 43 is connected between the plug 10 and the tail socket 20 and also electrically extends to each LED lamp 30a, 30b to provide the DC voltage for driving the LED lamps 30a, 30b. The signal wire 44 is connected to all LED lamps 30a, 30b in series to transmit the control data from the primary LED lamp 30a to other secondary LED lamps 30b. The control data contains the addresses information to select LED lamps 30a, 30b to be activated. For instance, if the addresses information includes the odd addresses, only the first, third, fifth . . . etc LED lamps will be turned on.
In conclusion, the light string in accordance with the present invention controls the LED lamps 30a, 30b by a primary circuit module 31a without using an additional control box and lowers the number of the wires connected among the plug 10, the tail socket 20 and the LED lamps 30a, 30b. Therefore, the fabricating cost and the possibility of light string breakdown resulted from the control box are reasonably reduced.
It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
