Resistive bypass for series lighting circuit

Abstract

A resistor bypass circuit for a series lighting circuit includes a plurality of serially connected light sources and a bypass resistor being connected in parallel with at least one of the respective light sources, each respective light source being low wattage and being capable operating on a one hundred percent duty cycle as desired.

Claims

1. A resistor bypass circuit for a lighting circuit comprising a plurality of serially connected LED light sources and a bypass resistor being connected in parallel with at least one of the respective light sources, said bypass resistor being in circuit and conducting current at all times across the light sources when current is flowing through the circuit regardless of whether the LED light sources are conducting current therethrough.

2. The resistor bypass circuit of claim 1, where the circuit is series-parallel connected.

3. The resistor bypass circuit of claim 1 wherein at least one of the light sources is a semiconductor providing a twinkling effect, and wherein the semiconductor light source utilizes electronic circuits that control the flashing rate of the light source.

4. The resistor bypass circuit of claim 1, wherein the LED light source uses 0.20 watts or less.

5. The resistor bypass circuit of claim 1, at least one of the light sources is a semiconductor light source providing a twinkling effect.

6. The resistor bypass circuit of claim 1, at least one of the light sources is a semiconductor light source utilizing electronic circuits that control the flashing rate of the light source, which would only affect the individual lighting element as the resistive bypass would allow current to continue to flow in remaining lighting elements in the series circuit.

7. The resistor bypass circuit of claim 1, wherein said light source is a blinking LED with a first state allowing current to flow through the device and a second state where the light source is an open circuit, whereby remaining light sources in the light string operate with current passing through the bypass resistor when the light source is in the second state.

8. The resistor bypass circuit of claim 1 being utilized in AC or DC circuits powered form a power source selected from the list consisting of batteries, step down transformers, AC utility power, or converters from AC to DC or DC to AC power, pulsed DC, and filtered or unfiltered DC, or partially filtered AC.

9. A resistor bypass circuit for a series lighting circuit comprising a plurality of serially connected LED light sources and a bypass resistor being connected in parallel with at least one of the respective light sources, said bypass resistor being in circuit and conducting current at all times when current is flowing through the circuit regardless of whether the LED light sources are conducting current therethrough and further including an LED flashing light source which includes a flashing circuit which causes the entire light circuit to flash.

10. A resistor bypass circuit for a lighting circuit comprising a plurality of serially connected LED light sources and a bypass resistor being connected in parallel with at least one of the respective light sources, said bypass resistor connected across the at least one light sources and being in circuit and conducting current at all times when current is flowing through the circuit regardless of whether the LED light sources are conducting current therethrough and wherein the resistance of the bypass resistor is equal to or greater than the inherent resistance of the light source to which the resistor is attached.

11. The resistor bypass circuit of claim 10, the light source being a semiconductor light source for providing color changing characteristics.

12. The resistor bypass circuit of claim 10, the semiconductor light source utilizing LED packages that incorporate two or more LED chips, and an integrated circuit (IC), the integrated circuit controlling each LED chip in respective LED packages independently.

13. The resistor bypass circuit of claim 12, the IC controlling the current and/or voltage to the individual LED chips in the LED package, the control providing for the mixing of the LED chip colors to get various resultant colors.

14. The resistor bypass circuit of claim 13, the control only affecting individual lighting element, the bypass resistor providing for current continuing to flow in remaining lighting elements in the series circuit.

15. A method of bypassing an LED light source, having a predetermined resistance to current flow, in a serially connected LED light string having at least one light source, the method comprising the steps of a. selecting a bypass resistor with the following characteristics: i. a resistance greater than or equal to the predetermined resistance of said LED light source; ii. the ability to carry all of the current in the light string; and iii. the ability to operate at 100% duty cycle; b. inserting said bypass resistor in parallel with said at least one LED light source.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a circuit diagram of one embodiment of the present invention where the lighting sources are incandescent bulbs;

(2) FIG. 2 is a circuit diagram of one embodiment of the present invention where the lighting sources include LEDs;

(3) FIGS. 2a-2c show various configurations and locations of the current limiting resistor and series and series-parallel configurations of FIG. 2;

(4) FIG. 2D shows a circuit diagram of one embodiment using a full wave rectifier with an optional filter capacitor;

(5) FIG. 3 is a diagram of a light string embodiment of the present invention where the lighting sources are incandescent bulbs and the lighting element is a filament;

(6) FIG. 4a is a front and side view of a light source assembly where the light source is an incandescent bulb;

(7) FIG. 4b is a front and side view of a light source assembly that includes an incandescent light bulb and a resistor;

(8) FIG. 4c is a front and side view of a light source assembly that includes an incandescent light bulb, a resistor, and a large-diameter lamp holder;

(9) FIG. 4d is a front and side view of a light source assembly showing the brass contacts of the light source assembly and an alternate resistor mounting position;

(10) FIG. 5 is a diagram of a light string embodiment of the present invention where the light sources LEDs and the lighting element is an LED semiconductor chip;

(11) FIG. 6 is a front view of a light source assembly where the light source includes an LED encased in an epoxy lens;

(12) FIG. 7 is a diagram of one embodiment of the present invention that produces a twinkling effect and includes a split construction of a full wave rectifier;

(13) FIG. 8 is diagram of another embodiment of the present invention that produces a twinkling effect and includes traditional full-wave rectification;

(14) FIG. 9 is a front and close-up view of the present invention embodied in a wire tree branch;

(15) FIG. 10 is a front view of a needless artificial tree as used in a lighted green goods system of the present invention;

(16) FIG. 11 is a front view of an artificial tree with needles as used in a lighted green goods system of the present invention;

(17) FIG. 12 is a front view of one embodiment of a lighted green goods system using bypass circuit light strings;

(18) FIG. 13 is a view of a flexible lighting system with a bypass circuit using incandescent light sources;

(19) FIG. 14 is a view of a flexible lighting system with a bypass circuit using LED light sources;

(20) FIG. 15 is an elevational view of a prior art bulb;

(21) FIG. 16 is an elevational view of a bulb of the present invention; and

(22) FIG. 17 is an elevational view of a bulb of a further embodiment of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

(23) The resistive bypass circuit 10, being a set or sting of lights, as shown in FIG. 1 includes a power source 12, light sources 14, and bypass resistors 16. Power source 12 is shown in FIG. 1 is a 120 volt alternating current (AC) power source, power source can be any voltage AC, direct current (DC), AC converted to DC, or DC converted to AC, both filtered or unfiltered DC, and pulsating DC or any other power source that can power the lighting sources. Light sources 14 may include incandescent bulbs, LEDs, or other lighting devices. Light sources 14 of FIG. 1 are incandescent bulbs.

(24) Bypass resistors 16 are configured in parallel with light sources 14, and combinations of bypass resistors 16 and light sources 14 are configured in series. Light sources 14 and bypass resistors 16 may be packaged together into light source assemblies 18. When all light sources 14 are operating properly, a portion of the total current flowing through bypass circuit 10 flows through light source 14, while the remainder flows through bypass resistor 16.

(25) In the event that a light source 14 ceases to conduct, and current flow is interrupted through that light source 14, the total current will flow through its corresponding bypass resistor 16. A missing, broken, or improperly connected light source 14 may cause a light source 14 to fail to conduct. In the case where light source 14 is an incandescent bulb, filament failure, or burnout, may be the cause of a light source failing to conduct. Without bypass resistors 16 operating in parallel with light sources 14, any failure in a light source 14 would interrupt power to all other light sources 14. The values of bypass resistors 16 are typically the same, and are chosen such that an appropriate current flows through light sources 14 when all light sources are operating properly.

(26) FIG. 2 illustrates another embodiment of the present invention that uses LEDs as a light source. Resistive bypass circuit 20 includes power source 12, light sources 26, optional current limiting resistors 24, and bypass resistor 28. Light sources 26, optional current limiting resistors 24, and bypass resistors 28 may be packaged together into light source assemblies 22. In the embodiment shown in FIG. 2, light source 26 is a single LED, preferably of equal to or less than 0.25 W. In other embodiments, light source 26 may be an LED chip that includes more than one LED. Those skilled-in-the-art will appreciate that the value of current limiting resistors 24 will be chosen based on the type of light source 26, the number of light sources 26, the number of bypass resistors 24, and the number and value of bypass resistors 28.

(27) In the embodiment shown in FIG. 2, power source 12 provides power to bypass circuit 20. When all light sources 26 are operable, current flows through the circuit, with a portion of the total current flows through the path containing current limiting resistor 24 and light source 26, while the remainder flows through bypass resistor 28. When current flow is interrupted through a light source 26, total current flows through the corresponding bypass resistor 28, allowing the remaining light sources 26 to operate.

(28) Resistive bypass circuits 10 and 20 may be used with any series, or series-parallel connected lighting device where failure of the bulb or its connection will turn off some or all of the bulbs. This includes mini-bulb lighting strings used for Christmas and other holiday decorative lighting, rope lights (also known as flexible lighting) and other general lighting applications that use series connected lamps or LEDs, such as a LED desk lamp, or under-counter light.

(29) Power source 12 is shown in FIG. 2 is a 120 volt alternating current (AC) power source, power source can be any voltage AC, direct current (DC), AC converted to DC, or DC converted to AC, both filtered or unfiltered DC, and pulsating DC, or any other power source that can power the lighting sources.

(30) FIGS. 2a-2c show various configurations and locations of the current limiting resistor and series and series-parallel configurations of FIG. 2. FIGS. 2a and 2b, show light source assemblies, 22, that contain only the light source, 26, and the bypass resistor, 28, with the current limiting resistor located outside of the light source assembly 22.

(31) FIG. 2D shows a circuit diagram utilizing a filtered full wave rectifier, 82 with an optional filter capacitor 84. The full wave rectifier could be replaced by a single rectifier diode, 76, to produce ½ wave rectification, and can be optionally filtered by capacitor 84. If a large enough capacitor 84 is selected, utilizing a single diode, 76, it could simulate full wave rectification to the circuit.

(32) It was desired to utilize incandescent bulbs with the resistive bypass circuit 10 as shown in FIG. 1. In order to make the resistor set 10 work with modern, high temperature materials, it was needed to reduce the wattage of the bulbs to at least 0.25 W (standard bulbs in the industry are either the common 0.425 W bulb, or the less common 0.35 W bulb, as noted in prior art FIG. 15), but it is preferable to use 0.20 Watts. Sets using 0.25 W bulbs are on the edge of passing ANSI/UL standards, a critical condition for placing such sets in the marketplace. The 0.20 W bulbs, on the other hand, more safely allow the set to operate, however, either could be used.

(33) While the 0.25 W bulbs (2.5V, 100 mA) were close in brightness to the 0.425 W bulbs (2.5V, 170 mA) that are commonly used, by using a thinner filament wire or other techniques to compensate for lumen output, the brightness of the 0.25 watt bulb is substantially equal to the standard 0.425 bulb. A conventionally constructed 0.20 W bulb (2.5V, 80 mA) bulb is even dimmer than the 0.35 W bulb (2.5V, 140 mA), and in the holiday market, the market demands bright bulbs.

(34) To make up for the shortcomings of a conventionally constructed 0.20 W bulb, the bulbs of the present invention, noted generally at 600 in FIGS. 16 and 17, employ a higher purity tungsten filament, along with a tighter coil of the filament 602. Further, the filament 602 is disposed higher into the bulb canopy 608 by the dimension H, noted in FIG. 15. The filament 602 is connected by relatively longer leads 604 than the leads 504 of the prior art that support the prior art filament 502. An advantage of such disposition is that losses from the plastic bulb adaptor 606 at the bottom of the bulb 600 did not absorb as much light. Such disposition of the filament 602 provides for a measurably brighter bulb 600, and also, as viewed by the human eye, an even brighter bulb 600 is perceived as compared with the prior art construction of FIG. 15, as the filament 602 is higher up into the bulb canopy 608, a construction that hasn't been done in the industry.

(35) Further, to enhance the brilliance of the reduced wattage, one version of the low energy bulb 600 of the present invention, the filament 602 is formed of a purer form of tungsten and is of thinner construction as compared to the prior art bulb 500. Additionally, the filament 602 is wound tighter than the filament 502 of the prior art. However, one skilled in the art would recognize that if brighter bulbs were not desired, standard bulb construction could be utilized.

(36) In addition, as noted with respect to FIG. 2 above, resistor sets 10 may be employed with light sources 26 being LEDs. Such LEDs typically operate at much lower current (20 mA) with a power draw of 0.08 W or less, and therefore allow for very cool operation of the resistor bypass circuit 28, even when the bypass resistor 28 is continually conducting. In either case, there is substantial energy savings. In another embodiment, higher power LEDs or several LEDs in parallel may be employed across the bypass resistor.

(37) The above noted features allow the resistor bypass circuit 10 to operate as a twinkling set by inserting a flasher bulb into any part of the circuit or, if provided, into a socket socket. Flasher bulbs are bulbs where a bimetallic strip heats, and open circuits the bulb (see for example, Fisherman), where a normal holiday light set that creates a twinkling effect has to use twinkling bulbs, where when the bimetallic strip is heated by the filament, it shorts out the bulb, allowing the remaining bulbs to light. In such sets where the bulbs short, ANSI/UL has very stringent requirements for construction and operation. In contrast however, in the resistor bypass set 10 of the present invention, use of a flasher bulb is not restricted, nor does it pose any additional safety concerns, as when the flasher bulb open circuits, it allows the resistor bypass set to work as it would normally, and actually reduces the current to the remaining bulbs, allowing the remaining bulbs to run cooler, as compared to the twinkle bulb set where it operates hotter when one or more bulbs is in the shorted condition.

(38) The resistor bypass set 10 also has the advantage of being a safer set than the standard mini light sets that commonly use a shunt wire inside the bulb to allow the current to continue flowing, as sets containing shunted bulbs create short circuits across the bulb, further dividing the input voltage by the remaining bulbs, increasing the power drop across each bulb. The increased power drop increases the surface temperature of the bulb, and causing the remaining bulbs in the set to burn out faster. This repeated action causes the bulbs to become very hot, where as the resistor bypass set 10 of the present invention operates such that every bulb failure, places a higher resistance into the set than the bulb it replaces, causing the remaining bulbs to proportionally dim, causing them to increase their life, and to run cooler. However, the resistor could be sized such that the current is not reduced, and may remain relatively constant, or even slightly increase, depending on the effect desired.

(39) FIG. 3 is an embodiment of the present invention in the form of a series-connected decorative light string 30. Decorative light string 30 includes power plug 32, optional light source assemblies 34, incandescent bulbs 36 and bypass resistors 16. Power plug 32 may directly plug into utility power (120V, 208V, 220V, 240V, 280V, etc), connect to a step down power supply (such as a Class 2 power supply) or may be omitted for direct connection to a power source. As shown in FIG. 3, incandescent bulbs 36 may be a miniature bulb-type (mini bulb) operating on 2.5 VAC at 70-120 mA, or some other low current draw bulb. Resistors 16 may be in the range of 30 ohms to 60 ohms, though the value of resistors 16 will vary according to the total current flow desired, as well as according to other factors mentioned above. Resistors 16 are configured in parallel with light sources 36. Light source assemblies 34, if provided, are configured electrically in series with each other. As indicated earlier, when a light source assembly 36 fails, total system current will flow through the corresponding bypass resistor 16, allowing the other light sources 36 to remain lit.

(40) In one embodiment of the decorative light string 30 includes one or more light source assemblies 34 that includes a flashing device, but does not include a bypass element 16 in parallel, causing all of the remaining light source assemblies 34 in the series circuit of decorative light string 30 to flash.

(41) Some methods of making light source assemblies 34 are further described in FIGS. 4a-d, but the present invention is not limited to the embodiments depicted in the figures. FIG. 4a illustrates a light source assembly 34a including a light source 36a in the form of a mini bulb, and a lamp holder 35a. FIG. 4b illustrates a light source assembly 34b that includes a light source assembly 34b, a light source 36b in the form of a mini bulb, a bypass resistor 16, and a lamp holder 35b. Lamp holder 35b may be larger than lamp holder 35a to accommodate bypass resistor 16. Bypass resistor 16 is connected across light source 36b in parallel. The connection may be accomplished by soldering, crimping, friction fit, compression fit, or other means, including connecting to a pair of brass contacts (not shown), to the leads of light source 26b, or to other conductors.

(42) FIG. 4c illustrates yet another light source assembly, light source assembly 34c, which includes a light source assembly 34c, a light source 36c in the form of a mini bulb, a bypass resistor 16, and a lamp holder 35c. In this embodiment, lamp holder 34c is even larger than lamp holder 35b.

(43) FIG. 4d illustrates another light source assembly, light source assembly 34d, which includes a light source assembly 34d, a light source 36d in the form of a mini bulb, a bypass resistor 16, and a lamp holder 35d. In this embodiment, lamp holder 34d may be longer than lamp holder 35b. In the embodiment shown in FIG. 4, one lead of bypass resistor 16 can be crimped to the brass contact. The other lead of bypass resistor 16 may be crimped to a second brass contact 17, or connected by other means, such that it is electrically in parallel with light source 36d. Other means includes being connected to the leads of light source 36. In addition to crimping, soldering, friction fit, compression, and other common connection means may be employed.

(44) In yet another embodiment, light sources 36 may be mini bulbs filled with an inert gas. Since the use of a bypass resistor 16 has the potential to decrease current flow through light sources 36, an inert gas, such as Krypton, can be used in place of a vacuum to allow for the bulb filament to burn whiter and maintaining the same bulb life expected from mini bulbs and get even closer to a standard mini bulb brightness.

(45) Lamp holders 35 of light source assemblies 34 may include molded lamp holders, assembled-on lamp holders, heat-shrink formed lamp holders, and other types of lamp holders. Light sources 36 may be removable, or non-replaceable. In another embodiments, the light source assemblies 34 may by mounted on a rigid or flexible printed circuit board, or connected directly to conductors or wires.

(46) Another embodiment of the present invention is a light string 40 as shown in FIG. 5. Light string 40 includes an optional power plug 42, light sources 26, current-limiting resistors 24, and bypass resistors 28. Light sources 26, current limiting resistors 24, and bypass resistors 28 may be packaged together into light source assemblies 44. The embodiment as shown works substantially as described above.

(47) One embodiment of light source 44 is shown in FIG. 6. Lamp holder base 33 houses bypass resistor 28, brass contacts 17, and the ends of wires 45. Bypass resistor 28 is connected to brass contacts 17 or other contact material to create a parallel configuration. Brass contacts 17 may be crimped on to wires 45 or other conductors. The optional lamp holder adapter 48 attaches to epoxy or some other material lens 46. The lens 46 encases light source 26, where light source 26 in this embodiment is an LED.

(48) In another embodiment, the bypass resistor 28, may be located directly across the LED leads 49 outside of any optional lens material, 46.

(49) In an alternate embodiment, the bypass resistor 28 may be located within the LED lens material 46 in parallel with the LED, or even inside the glass bulb envelope for incandescent bulbs.

(50) FIG. 7 illustrates another embodiment of the present invention, light string 50, that utilizes partial rectification and blinking LEDs inside the epoxy lens. Light string 50 includes a power plug 52, end connect 53, and light source assemblies 54 and 56. Light source assemblies 54 are connected in a series configuration. Light source assemblies 56 are connected to the series-connected light sources 54 as shown in FIG. 7.

(51) Light source assemblies 56 includes a bypass resistor 58, optional current limiting resistor 60, light source 62, which in this embodiment is an LED, and diode 64. Light source assembly 56 may also includes a lamp holder (not shown), similar to the ones described above.

(52) Light source assemblies 54 includes a bypass resistor 58, optional current limiting resistor 60, and light source 62 or light source 66. In this embodiment, light source 62 is an LED chip, and light source 66 is a “blinking” LED that incorporates a chip that turns the LED on and off for a blinking or flashing effect. Operation of light source 66 is independent of the other light sources 62 due to the bypass resistor 58. Light source assembly 54 may also includes a lamp holder (not shown), similar to the ones described above. Circuit 50 may utilize more than one blinking LED 66, per circuit, or may only include blinking LED 66 as its light source.

(53) In this embodiment, diodes 64 provide full-wave rectified power to light source assemblies 54, causing light sources 62 and 66 of light source assemblies 54 to remain lit throughout most of the AC power cycle. Light source assemblies 56 receive partial rectification due to the particular configuration of FIG. 7, causing light sources 62 of light source assemblies 56 to be powered throughout approximately half the AC power cycle.

(54) When light source 66 is a blinking LED chip as shown in FIG. 7, current is periodically interrupted to the LED on the chip. Without bypass resistors 58, this would cause all light sources in light string 50 to lose power due to an interruption of current flowing through the series-connected circuit. However, bypass resistor 28 allows current to continue flowing, maintaining power to other light sources 62 and 66. Under normal operation, light source 66 will cause its LED to blink on and off, creating a twinkling effect, while other light sources 62 remain powered and lit. The use of multiple light sources 66 in a light string 50 creates a desirable twinkling effect as light sources 66 turn on and off, while light sources 62 remain lit.

(55) In another embodiment, Light source 66 may be a multi LED chip configuration, programmed to change the light output color of the light source. Alternate embodiments may use a light source 66 where the bypass device 80 is an electronic circuit, or integrated circuit across the LED leads inside or outside of the epoxy housing/lens.

(56) FIG. 8 illustrates another embodiment where, a resistive bypass circuit 70 utilizes full-wave rectification to provide power to all light sources 62 and 66. Resistive bypass circuit 70 includes an AC power source 72, full-wave rectifier 74 with optional filter capacitor (not shown), main current limiting resistor 78, bypass resistors 80, light sources 66 and 62. Full-wave rectifier 74 includes four diodes 76. Full wave rectifier 74 may optionally employ one diode 76, and a sufficiently sized filter capacitor to simulate full wave rectification. The AC power source 72 may be any source voltage.

(57) In this embodiment, full-wave rectifier 74 provides DC power for bypass circuit 70. Main current limiting resistor 78 limits the total amount of current flowing through circuit 70 and is sized partially based on the number of light sources 62 and 66. The use of a single current limiting resistor 78 rather than multiple current limiting resistors simplifies design and manufacturing efforts, but may optionally be manufactured with multiple current limiting resistors as described in the embodiments above. Lights source 66 in the form of blinking LED chips, along with bypass resistors 80 create a twinkling effect when embodied in a light string. The size of bypass resistor 80 depends on the electrical characteristics of light source 66, but in one embodiment may be 300 to 600 ohms. In some embodiments, bypass resistor 80 may only be used in conjunction with light sources 66, and not with light sources 60. This configuration would enable the twinkling effect, but would eliminate the bypass function at light sources 62.

(58) Another embodiment is the use of circuit 70 in a DC-supplied circuit, such that full wave rectifier 74 is not required. Additional embodiments of circuit 70 are configured in a series-parallel configuration. In another embodiment, light source 66 may be a multi LED chip configuration, programmed to change the light output color of the light source.

(59) FIG. 9 depicts a decorative lighting sculpture 90 that includes an optional power plug 91, wires 98, optional connectors 96, main rod 92, branches 94, wires 100 and light source assemblies 102. Power plug 91 may be connected in one embodiment to a 45 VDC to 50 VDC class 2 transformer with an output of 1.2 A, though other voltage ranges and power sources may be used. Alternatively, light sculpture 90 may not include power plug 91 and may be directly connected a power source. Light source assemblies 102 may be similar in configuration to the other light source assemblies described above, utilizing incandescent bulbs, LEDs, or other light sources configured in parallel with a bypass resistor.

(60) In alternate embodiments, the bypass resistor may be replaced by bypass circuits utilizing transistors or other electronic active circuits.

(61) The circuits and light strings of the present invention as applied to artificial trees, wreaths, garlands, and other artificial greenery, or alternatively to medium to large decorative products, such as stars, figures, icons and other decorative products provide a number of advantages. Replacing light strings due to light sources that have failed on a light string that is attached to an artificial tree or other decorative product, can be a difficult task since the string is not easily removed from the tree or products and the use of electric testers is not practical due to the fields such products produce with the volumes of wires and optional metal support structures. The bypass circuits and light sets described herein ensure that the light string will continue to remain lit even in the event of a light source failure, meaning that the entire light string does not have to be removed from the tree or decorative product. The combination of circuits, light strings and tree make a reliable, convenient lighted green goods system. FIGS. 10-12 depict some of the artificial trees used in such a lighted green goods system.

(62) FIG. 10 shows one version of an artificial tree 140 that includes a tree trunk 148, branches 142, branch mains 144, and sub-branches 146. Artificial tree 140 may be constructed of a combination of many materials as described above. In this embodiment, artificial tree 140 is constructed primarily of painted metal, or in another embodiment made primarily of plastic, or a combination of plastic and metal.

(63) FIG. 11 shows another version of an artificial tree, 140′. Artificial tree 140′ includes tree trunk 148′, branches 142′, branch mains 144′, sub-branches 146′ and needles 149. Needles 149 are commonly derived from PVC, nylon, and/or PE and may be green in color to make artificial tree 140′ appear to be an evergreen or pine tree. In another embodiment it may use white needles and branches for different aesthetics.

(64) FIG. 12 light string, such as light string 30, 40, 50, 70, or a combination thereof, attached to branches 142 of tree 140 to form a pre-lit tree system 200. Light strings 30, 40, 50, 70, or other embodiments of the present invention, may be similarly attached to trees 140′. Light string 30, 40, 50, 70 is shown attached to tree 140 via clips 150. Clip 150 may include but are not limited to C clips, snap lock clips, and wire ties.

(65) FIGS. 13 and 14 depict the present invention in the form of flexible lighting, or rope lighting. Flexible lighting 300 as depicted in FIG. 13 includes an outer encasement 302, end cap 304, power cap 306, power cord 308, power plug 310, and one or more bypass circuits 312. Flexible lighting 300 may operate on 120 VAC, which is transmitted through power plug 310 and power cord 308, though other voltages may be used, and the input may be rectified or DC. Outer encasement 302 is typically made of a PVC material, and houses bypass circuit 312. Power cap 306 assists in attaching power cord 308 to bypass circuit 312 and may attach to outer encasement 302 by any number of known methods.

(66) Bypass circuits 312 are series circuits and each bypass circuit 312 is connected in parallel with the other. Bypass circuit 312 includes a plurality of light sources 314 electrically connected in parallel with bypass resistors 320. Light sources 318 may be incandescent bulbs, LEDs, or other light sources. As described in previous embodiments, bypass resistor 320 may be replaced with another active circuit device. Bypass circuit 312 may also include conductors 314 and 316 which extend the length of flexible lighting 300 and provide power to the bypass circuits 312 when more than one circuit 312 is employed.

(67) Operation of flexible lighting 300 is similar to those embodiments described above. During normal operation, current flows through both light source 318 and bypass resistors 320. If light source 318 fails, the entire bypass circuit 312 current flows through bypass resistor 320, allowing flexible lighting 300 to stay lit.

(68) FIG. 14 depicts a similar flexible lighting system that relies on LEDs, rather than incandescent bulbs. Flexible lighting 400 as depicted in FIG. 14 includes an outer encasement 402, end cap 404, power cap 406, power cord 408, power plug 410, and one or more bypass circuits 412. Flexible lighting 400 may operate on 120 VAC, which is transmitted through power plug 410 and power cord 408, though other voltages may be used, and the input may be rectified or DC. Outer encasement 402 is typically made of a PVC material, and houses bypass circuit 412. Power cap 406 assists in attaching power cord 408 to bypass circuit 412 and may attach to outer encasement 402 by any number of known methods.

(69) Bypass circuits 412 are series circuits and each bypass circuit 412 is connected in parallel with the other. Bypass circuit 412 includes a plurality of LEDs 414 electrically connected series with resistors 419. Series connected LEDs 414 and resistors 419 are electrically in parallel with bypass resistors 420. Light sources 418 may be LEDs, or other light sources. As described in previous embodiments, bypass resistor 420 may be replaced with another active circuit device. Bypass circuit 412 may also include conductors 414 and 416 which extend the length of flexible lighting 400 and provide power to the bypass circuits 412 when more than one circuit 412 is employed. The number or location of resistors 419 in each circuit 421 may vary based on circuit requirements, with some bypass circuits 412 not including a resistor 419. In other embodiments, resistor 419 may be located external to circuit 421, and in line with circuit Bypass circuit 412.

(70) Operation of flexible lighting 400 is similar to those embodiments described above. During normal operation, current flows through both light source 418 and bypass resistors 420. If light source 418 fails, the entire bypass circuit 412 current flows through bypass resistor 420, allowing flexible lighting 400 to remain lit.

(71) Other embodiments of flexible lighting 300 and 400 may incorporate twinkling, flashing and color changing properties as previously described above.

(72) It is desired to utilize incandescent bulbs with the embodiment of FIG. 1. In order to make the resistive bypass set 10 function with modern, high temperature materials, it was needed to reduce the wattage of the bulbs to at least 0.25 W (standard bulbs in the industry are the 0.30 W bulb). It is preferable to use bulbs of 0.20 Watts. Sets using 0.25 W bulbs are on the edge of passing ANSI/UL standards, a critical condition for placing the resistive bypass set 10 in the marketplace. The 0.20 W bulbs, on the other hand, safely allows the set to operate and readily meet ANSI/UL standards, however, either 0.25 W or 0.20 W bulbs could be used.

(73) In addition, the resistor sets with LED sources can also be employed, and as those typically operate at much lower current (20 mA) drawing approximately 0.08 W, those allow for very cool operation of the resistor bypass circuit. Additional embodiments may use a higher power LED or multiple LEDs connected in parallel across the resistive element.

(74) Both of these lighting changes (lower wattage/higher brightness bulbs, and LEDs) were not anticipated, or contemplated by Fisherman, therefore only restricting it to flasher bulbs, and the use in such a set where the bulbs are never fully off.

(75) In addition, this allows our resistor bypass set to operate as a twinkling set by inserting a flasher bulb into any circuit. Flasher bulbs are bulbs where the bimetallic strip heats, and open circuits the bulb, where a normal holiday light set that creates a twinkling effect has to use twinkling bulbs, where when the bimetallic strip is heated by the filament, it shorts out the bulb, allowing the remaining bulbs to light, however, in such sets where the bulbs short, ANSI/UL does not allow for such constructions in flexible (rope) lighting. However, in the resistor bypass set, use of a flasher bulb is not restricted, nor does it pose any additional safety concerns, as when the flasher bulb open circuits, it allows the resistor bypass set to work as it would normally, and actually reduces the current to the remaining bulbs, allowing to run cooler, vs. the twinkle bulb set where it operates hotter when one or more bulbs is in the shorted condition.

(76) The resistor bypass set also has the advantage providing a shunting circuit, as ANSI/UL standards do not allow for shunts that short circuit the bulb in rope (flexible) lighting, as the bulbs are not replaceable, and shorts caused by shunt wires in or out to the bulb would create an unsafe condition as more and more bulbs burn out. A shunt wire inside the bulb to allow the current to continue flowing, as those bulbs create short circuits, further dividing the input voltage by the remaining bulbs, increasing the power drop across each bulb, thereby increasing the surface temperature of the bulb, and causing the subsequent bulb to burn out faster, and this repeated action causing the bulbs to become very hot, where as the resistor bypass set operates such that every bulb failure, places a higher resistance into the set than the bulb it replaces, causing the remaining bulbs to proportionally dim, causing them to increase their life, and run cooler. However, the resistor could be sized such hat the current is not reduced, and may remain relatively constant.

(77) In addition to decorative lighting, the bypass circuits of the present invention may also be used in general lighting applications including portable lighting, auto lighting, traffic lights and the like.

(78) The invention addresses many of the deficiencies and drawbacks previously identified. The invention may be embodied in other specific forms without departing from the essential attributes thereof; therefore, the illustrated embodiments should be considered in all respects as illustrative and not restrictive. The claims provided herein are to ensure adequacy of the present application for establishing foreign priority and for no other purpose.