US 20100045186A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2010/0045186A1 Janning (43) Pub. Date: Feb. 25, 2010

(54) DUAL BRIGHTNESS TWINKLE INA Publication Classification MINATURELIGHT BULB (51) Int. Cl. HOI. I. 7/34 (2006.01) (76) Inventor: obs L. Janning, Bellbrook, OH (52) U.S. Cl...... 315/73 (57) ABSTRACT Correspondence Address: A circuit for high-low flashing in a series-wired light string DCKSTEIN SHAPRO LLP circuit. The series-wired light string includes miniature 1825. EYE STREET NW incandescent bulbs disposed in respective light Sockets. A Washington, DC 20006-5403 (US) resistive element connected in series with a bi-metallic ther mal Switching element is mounted—as a —either inside (21) Appl. No.: 12/611,656 the light socket or inside the bulb, so as to be connected in parallel with the bulb filament. The bi-metallic thermal (22) Filed: Nov. 3, 2009 Switching element, in series with the resistive element, elec trically switches the resistive element off and on across the Related U.S. Application Data bulb filament. The bi-metallic thermal switching electrical contacts are in the normally closed position. Because the (63) Continuation-in-part of application No. 1 1/687,882, resistive element is in parallel with the bulb filament when the filed on Mar. 19, 2007, Continuation-in-part of appli- bi-metallic Switching element is in its normally closed posi cation No. 12/247,975, filed on Oct. 8, 2008, which is tion, the bulb filament brightness is at its low state. As current a continuation-in-part of application No. 12/029,329, flows through the resistive element and the bi-metallic ther filed on Feb. 11, 2008, which is a continuation-in-part mal Switching element, the bi-metallic Switching element is of application No. 1 1/542,184, filed on Oct. 4, 2006, warmed and activated and moves from its normally closed now Pat. No. 7,342,327. position to an open position. The shunt is now removed from across the bulb filament and the bulb illuminates brighter. (60) Provisional application No. 61/271,539, filed on Jul. Since the resistive element no longer passes current through it 22, 2009, provisional application No. 61/273,887, when it opens, it cools. When it cools sufficiently, the bi filed on Aug. 10, 2009, provisional application No. metallic Switching element moves back to its normally closed 61/276,846, filed on Sep. 17, 2009. position. The cycle is repeated.

Bulb

Fiament

3.5 W 170 mA

Thermal Non-Illuminated Element filament ~24 WG) 80 mA

pI

Patent Application Publication Feb. 25, 2010 Sheet 1 of 4 US 2010/004S186 A1

Figure 1

Frt 25 A 3 with A sw it is C. A s: gulls is

Shirt ir

Figure 2 Patent Application Publication Feb. 25, 2010 Sheet 2 of 4 US 2010/004S186 A1

Bulb

Fiament 3.5 W 170 mA

Non-Illuminated LLI(12 E {i} Π4 filament ~24 WG) 80 mA

Figure 3 Patent Application Publication Feb. 25, 2010 Sheet 3 of 4 US 2010/004S186 A1

2, W if fei, WTO is: 3W i. 5 it tra SW 17. A it. s 3.

WAC

35W t? A b

Figure 4 Patent Application Publication Feb. 25, 2010 Sheet 4 of 4 US 2010/004S186 A1

Bulb

Filament 3.5 W 170 mA

Non-luminated Filament 24 V G) 80 mA Chip

2. Shunt ...... C. Wiring

US 2010/004S186 A1 Feb. 25, 2010

DUAL BRIGHTNESS TWINKLE INA lamp is that it is normally in the brightest state, and if the MINATURELIGHT BULB thermal element fails, the lamp remains in the highest output state, which is dangerous. The high-low twinkle flasher bulb CROSS-REFERENCE TO RELATED of Davis, Jr. also relies upon radiant heat from the filament to APPLICATIONS activate and deactivate the thermal element, rather than pro 0001. This application claims the benefit of Provisional viding a thermal element that is more reliably heated directly No. 61/271.539, filed Jul. 23, 2009, Provisional Application by current passing through the element. No. 61/273,887, filed Aug. 10, 2009, and Provisional Appli 0007. The present invention overcomes the disadvantages cation No. 61/276,846, filed Sep. 17, 2009. noted above by providing a circuit for dual brightness twinkle 0002 This application is a continuation-in-part of appli in which the bulb is normally in the low brightness state, and cation Ser. No. 12/247,975, filed Oct. 8, 2008, which is a which includes a thermal element that is activated by current continuation-in-part of application Ser. No. 12/029.329, filed passing through the thermal element to switch the bulb to a Feb. 11, 2008, which is a continuation-in-part of application high brightness state. Ser. No. 1 1/542,184, filed Oct. 4, 2006, now U.S. Pat. No. 7.342.327, all of which are incorporated herein by reference. SUMMARY OF THE INVENTION BACKGROUND OF THE INVENTION 0008. In accordance with the present invention, current 0003. One of the most common uses of light strings is for passes through a resistive element connected in series with a decoration and display purposes, particularly during Christ bi-metallic thermal Switching element which is mounted—as mas and other holidays, and more particularly for the deco a shunt—either inside the light Socket or inside a miniature ration of Christmas trees, and the like. Probably the most lightbulb, so as to be connected in parallel with the miniature popular light set currently available on the market, and in light bulb filament. The bi-metallic thermal switching ele widespread use, comprises one or more strings of fifty min ment, in series with the resistive element, electrically iature light bulbs each, with each bulb typically having an switches the resistive element off and on across the bulb operating rating of 2.5 volts, and whose filaments are filament. The bi-metallic thermal switching electrical con connected in an electrical series circuit arrangement. tacts are in the normally closed position. Because the resistive 0004. Often, in holiday lighting, flasher bulbs are incor element is in parallel with the bulb filament when the bi porated in the series-wired string of lights in order for the metallic Switching element is in its normally closed position, entire light string to go off and on. Recently, Christmas light the bulb filament brightness is normally in its low state. As strings have become available with miniature lightbulbs that current flows through the resistive element and the bi-metallic flash off and on individually without the entire light string thermal Switching element, the bi-metallic Switching element flashing off and on. The parent patents of the present appli is warmed and activated and moves from its normally closed cation, upon which priority is claimed, teach Such a circuit, position to an open position. The shunt is now removed from which is shown in FIG. 1. A microchip or other voltage across the bulb filament and the bulb illuminates brighter. responsive shunt 22-31 in the sockets of the flasher bulbs Since the resistive element no longer passes current through it 12-21 continues the current through the series-wired light when it opens, it cools. When it cools sufficiently, the bi string when the flasher bulb in the socket goes off and the metallic Switching element moves back to its normally closed circuit opens. The off-on action of the flasher bulbs 12-21 is position. The cycle is repeated. Thus, the present invention controlled by a bi-metallic switching element inside the bulb. provides dual brightness from a single filament. Initially, current flows through the bi-metallic element en 0009. In another embodiment of the invention, a Triac or route to the bulb filament. In doing so, it warms and pulls SCR is used in place of the bi-metallic switching element, i.e., away from a contact that connects it to the bulb filament, thus a Triac or SCR in series with a resistive element is connected opening the circuit and extinguishing the bulb. Upon cooling, in parallel with the bulb filament and acts as a shunt, switch the bi-metallic Switching element resumes contact and the ing the resistive element on and off across the bulb filament at bulb lights again. The cycle is repeated. a rate of approximately 10 to 20 times a minute as the Triac or 0005 Random twinkling of is a desirable SCR switches on and off. feature in decorative lighting, including the series-wired light 0010. The brightness levels in the dual brightness twinkle strings with flashers described above. However, it would be bulb of the present invention are determined by the bulb desirable to provide random twinkling at various levels of parameters and the resistive shunt. For example, to achieve a illumination—i.e., high-low twinkling in a series-wired light “twinkle-bright' type of operation, where the bulb would get String. brighter than the other bulbs in the light string, a bulb with a 0006 U.S. Pat. No. 2,235,360 to Davis, Jr. teaches a higher Voltage rating but the same current rating is used flasher lamp with dual series connected filaments, and with a for the dual brightness bulb. Suchabulb would dissipate more thermal element permanently connected at one side to a lead power and give off more light in the unshunted state. The low to a first one of the filaments. As the thermal element is heated end brightness is controlled by the resistive element used to by the first filament, it moves into contact with a dummy lead shunt the main filament. The lower the resistance, the lower wire connected to a point between the two filaments, thereby the bulb brightness will be in the dual brightness operation. shorting out the first filament, and diminishing the light out 0011 Advantageously, since the high-low lightbulb of the put by the bulb. As the first filament cools, the thermal ele present invention is normally in the minimum brightness State ment cools, whereby it moves back out of contact with the and as the bi-metallic Switching element is activated, the dummy lead wire, thereby allowing current to pass again brightness increases to its maximum state. Thus, if a bulb fails through the first filament, and increasing the light output from to flash, it is not a problem, as the bulb remains in the safe, low the bulb. The problem with such a high-low twinkle flasher brightness state. US 2010/004S186 A1 Feb. 25, 2010

0012. Other features and advantages of the present inven power and give off more light in the unshorted state. The low tion will become apparent when the following description is end brightness is controlled by the resistive element used to read in conjunction with the accompanying drawings. shunt the bulb filament. The lower the resistance, the lower the bulb brightness will be in the dual brightness operation. In BRIEF DESCRIPTION OF THE DRAWINGS the preferred embodiment, the brightness is set in the low 0013 FIG. 1 is an electrical schematic diagram of a series illumination state to that of the other bulbs in the light string. wired light string employing a conventional flasher bulb., This is easily done by selecting the proper resistance value for 0014 FIG. 2 is electrical schematic diagram of a first the resistive element R. embodiment of the present invention with a resistive element 0020 While the example given is for 170 mA mini-light connected in series with a bi-metallic thermal Switching ele bulbs rated at 2.5 volts, other voltage bulbs with other current ment—as a shunt—mounted inside the light Socket, con rating values could be used as well. The preferred thermal nected in parallel with the miniature light bulb filament dis switching element TS is that of the reed type for fast acting posed in the Socket; performance. The bi-metallic element is selected so that the 0015 FIG. 3 shows a second embodiment of the present flashing of the bulb from the low brightness to the high invention with a resistive element connected in series with a brightness occurs at a rate of not more than 40 times per bi-metallic thermal Switching element—as a shunt— minute, preferably 10 to 20 times per minute. mounted inside the miniature lightbulb, connected in parallel 0021. Another embodiment of the invention with bulbs of with the miniature lightbulb filament. different voltage ratings is shown in FIG. 3. The main fila 0016 FIG. 4 is electrical schematic diagram of a third ment in this preferred embodiment of the twinkle bulb is embodiment of the present invention with a resistive element again rated higher (3.5 volt, 170 mA) than the other mini connected in series with a Triac or SCR-as a shunt— lights (2.5 volt, 170 mA) in the series-wired light string, but in mounted inside the light Socket, connected in parallel with the this embodiment, the twinkle bulb has a bypass non-illumi miniature light bulb filament disposed in the socket nated filament in the bulb connected in parallel with the main 0017 FIG. 5 shows a fourth embodiment of the present filament to partially shunt the main filament such that its invention with a resistive element connected in series with a brightness is normally comparable with the other (2.5 volt) Triac or SCR-as a shunt—mounted inside the miniature bulbs in the light string. As shown in FIG. 3, the bi-metallic lightbulb. element is positioned in close proximity to the non-illumi nated filament as well as from the current passing through the DESCRIPTION OF THE PREFERRED bi-metallic element. As current flows through the bi-metallic EMBODIMENT element and the non-illuminated element, the bi-metallic ele 0018. The random high-low twinkling of the present ment (Switch) moves from its normally closed position to an invention is provided by using bulbs of different voltage open position due to warming. Thus, the non-illuminated ratings. FIG. 2 shows a series-wired Christmas light string filament shunt is removed from being across the main fila containing mostly 2.5 volt 170 mA bulbs. In selected sockets ment and the main filament glows brighter. As the bi-metallic having a thermal shunt connected thereacross, consisting of a element cools, it goes back to its normally closed position resistive element Rand a thermal switch TS, the bulbs are of again which connects the non-illuminated filament across the a higher Voltage rating. In this case, they are shown to be 3.5 main filament again, reducing its brightness to that of the volt 170 mA bulbs. The voltage rating of the bulb is selected other bulbs in the light string. The bi-metallic element is for the high brightness point of the dual brightness lightbulb selected so that the flashing of the bulb from the low bright in the string. The current rating of the bulb should be the same ness to the high brightness occurs at a rate of not more than 40 as the other bulbs in the string. The resistive element R can be times per minute, preferably 10 to 20 times per minute. a resistor or it can be part of the thermal switch TS. A resis 0022. The non-illuminated filament does not illuminate tance value for the resistive element shunt across a bulb in a because it has a Voltage rating that is much higher that the light String having multiple 2.5 volt mini-lights wired in elec Voltage that would appear across the main filament. In this trical series, and operating at 120 volts AC and 170 mA, preferred embodiment, a 24 volt filament rated at 80 mA is would be between 50 and 100 ohms, with a typical value of 65 used as the shunt. ohms. This value might be chosen to set the low end bright 0023. In still further embodiments of the invention with ness of the dual brightness operation to that of the other bulbs bulbs of different voltage ratings, shown in FIGS. 4 and 5. in the String. In this manner, one sees the bulbs at normal current passes through a Triac or SCR shunt circuit connected brightness, and then, selected bulbs get brighter for a short in parallel with the bulb filament, either in the socket (FIG. 4) duration—for example, a few seconds—and then back again. or in the bulb (FIG. 5). In another words, in these embodi This cycle is repeated. The observersees a random “twinkle ments of the invention, a Triac or SCR is used in place of the bright light string with selected lights changing in illumina bi-metallic switching element of the prior embodiments. A tion. Triac or SCR in series with a resistive element is thus con 0019. The brightness levels in this dual brightness twinkle nected in parallel with the bulb filament and acts as a shunt, bulb circuit are determined by the bulb parameters and the switching the resistive element on and off across the bulb resistive shunt. For example, to achieve a “twinkle-bright' filament at a rate of approximately 10 to 20 times a minute as type of operation, where the bulb would get brighter than the the Triac or SCR switches on and off. Because the resistive other bulbs in the light string, a bulb with a higher voltage element is essentially in parallel with the bulb filament, when rating but the same current rating is used for the dual the Triac or SCR fires, the bulb filament brightness is lowered. brightness effect. If 2.5 volt 170 mAbulbs are used in the light When the in the Triac or SCR shunt circuit expends string, the designated dual brightness bulb might be rated at it energy and the Triac or SCR switches off, the bulb filament 3.5 volts and 170 mA. Such a bulb would dissipate more brightens as the resistive shunt is removed from across the US 2010/004S186 A1 Feb. 25, 2010

filament. The cycle is repeated. This dual brightness from a 2. A series-wired light string as recited in claim 1, wherein single filament is novel, as in the other embodiments of the the shunt circuit is disposed in the socket of the bulb having a invention. higher Voltage rating. 0024. As in the prior embodiments, the brightness levels in 3. A series-wired light string as recited in claim 1, wherein the Triac or SCR embodiment are determined by the bulb the shunt circuit is disposed in the bulb having a higher parameters and the resistive shunt. Again, the dual brightness Voltage rating. bulb might be rated at 3.5 volts and 170 mA whereas the other 4. A series-wired light string as recited in claim 1, wherein bulbs of the string might be rated at 2.5 volts and 170 mA. The the bulbs having a higher Voltage rating are further provided dual brightness bulb would dissipate more power and give off with internal shunt wiring extending between the filament more light in the unshunted state. The low end brightness is leads. controlled by the resistive element used to shunt the main 5. A series-wired light string as recited in claim 1, wherein filament. The lower this resistance, the lower the bulb bright the thermal element comprises a bi-metallic Switching ele ness will be in the dual brightness operation. ment. 0.025 A resistance value for the shunt resistive element for 6. A series-wired light string as recited in claim 1, wherein a 3.5 volt 170 mA mini-light bulb operating in a light string the thermal element comprises a triac. having 49 other 2.5 volt mini-lights wired in electrical series 7. A series-wired light string as recited in claim 1, wherein and operating at 170 mA would be between 60 and 130 ohms, the thermal element comprises an SCR. with a typical value of 110 ohms. 8. A method of operating a series-wired light string com 0026 FIG. 4 shows a typical series-wired light string with prising a plurality of lightbulbs including a plurality of light two dual brightness bulb assemblies and their associated bulbs having a voltage rating higher than the other bulbs of the shunt circuits connected thereacross. series-wired light string, a plurality of light sockets, each light 0027 FIG. 5 shows the Triac or SCR circuit contained socket of the plurality of light sockets adapted to receive at primarily on a chip, with the chip inserted inside the bulb at least one of the plurality of light bulbs, and a shunt circuit the time of bulb manufacture. The resistive shunt in this case disposed across the filament of the bulb having a higher might be a non-illuminated filament or it could just be a Voltage, the shunt circuit comprising a resistive element and a resistor contained on the chip. The non-illuminated filament thermal element that moves alternately between an open posi in FIG. 5 is shown as rated at 24 volts at 80 mA. This value tion and a closed position as the thermal element heats when might change to a different value depending on the desired current is passing therethrough and cools when current is not brightness at the low level. passing therethrough, 0028. Having so described and illustrated the principles of wherein, when the thermal element is in the closed position my invention in a preferred embodiment, it is intended, there with current passing therethrough, the filament of the fore, in the annexed claims, to cover all Such changes and bulb having a higher voltage is shunted by the resistive modifications as may fall within the scope and spirit of the element, such that the filament carries less current and following claims. produces light of a low brightness, and wherein, when the thermal element heats up as current What is claimed is: passes therethrough and moves to an open position, the 1. A series-wired light string, comprising: filament is no longer shunted by the resistive element a plurality of lightbulbs, including at least one bulb having and carries full current, whereby the filament produces a voltage rating higher than the other bulbs of the series light of a high brightness, thereby causing the lightbulbs wired string; having a higher Voltage rating to produce illumination of a plurality of light Sockets, each light Socket of the plurality a high and low brightness at different times to cause the of light sockets adapted to receive at least one of the light string to exhibit a twinkling effect. plurality of light bulbs; and 9. A method of operating a series-wired light string as a shunt circuit disposed across the filament of the bulb recited in claim 8, wherein the bulb having a higher voltage having a higher Voltage, the shunt circuit comprising a rating intermittently flashes to the higher brightness for a resistive elementandathermal element that moves alter period of at least one second before relaxing to its originallow nately between an open position and a closed position as illumination state the thermal element heats when current is passing there 10. A method of operating a series-wired light string as through and cools when current is not passing there recited in claim 8, wherein the bulb having a higher voltage through, rating flashes from the low brightness to the high brightness at wherein, when the thermal element is in the closed position a rate of not more than forty times per minute. with current passing therethrough, the filament of the 11. The series-wired light string of claim 10, wherein the bulb having a higher voltage is shunted by the resistive flashing rate is ten to twenty times per minute. element, Such that the filament carries less current and 12. A flasher bulb for producing alternately high and low produces light of a low brightness, and illumination in series-wired light string comprising at least wherein, when the thermal element heats up as current one bulb having a voltage rating higher than the other bulbs of passes therethrough and moves to an open position, the the series-wired string, comprising: filament is no longer shunted by the resistive element a filament; and and carries full current, whereby the filament produces a shunt circuit disposed across the filament, the shunt cir light of a high brightness, cuit comprising a resistive element and a thermal ele thereby causing the light bulbs having a higher Voltage ment that moves alternately between an open position rating to produce illumination of a high and low bright and a closed position as the thermal element heats when ness at different times to cause the light string to exhibit current is passing therethrough and cools when current a twinkling effect. is not passing therethrough, US 2010/004S186 A1 Feb. 25, 2010

wherein, when the thermal element is in the closed position 14. A flasher bulb as recited in claim 12, wherein the with current passing therethrough, the filament of the thermal element comprises a bi-metallic Switching element. bulb is shunted by the resistive element, such that the 15. A flasher bulb as recited in claim 12, wherein the filament carries less current and produces light of a low thermal element comprises a triac. brightness, and 16. A flasher bulb as recited in claim 12, wherein the thermal element comprises an SCR. wherein, when the thermal element heats up as current 17. A flasher bulb as recited in claim 12, wherein the bulb passes therethrough and moves to an open position, the intermittently flashes to the high brightness state for a period filament is no longer shunted by the resistive element of at least one second before relaxing to its original low and carries full current, whereby the filament produces brightness state. light of a high brightness. 18. A flasher bulb as recited in claim 17, wherein the 13. A flasher bulb as recited in claim 12, wherein the bulb flashing rate is ten to twenty times per minute. is further provided with internal shunt wiring extending between the filament leads. c c c c c