WO1997046055A1 - Series connected light string with filament shunting - Google Patents
Series connected light string with filament shunting Download PDFInfo
- Publication number
- WO1997046055A1 WO1997046055A1 PCT/US1997/001831 US9701831W WO9746055A1 WO 1997046055 A1 WO1997046055 A1 WO 1997046055A1 US 9701831 W US9701831 W US 9701831W WO 9746055 A1 WO9746055 A1 WO 9746055A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- bulbs
- string
- bulb
- voltage
- illuminated
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B39/00—Circuit arrangements or apparatus for operating incandescent light sources
- H05B39/10—Circuits providing for substitution of the light source in case of its failure
- H05B39/105—Circuits providing for substitution of the light source in case of its failure with a spare lamp in the circuit, and a possibility of shunting a failed lamp
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B47/00—Circuit arrangements for operating light sources in general, i.e. where the type of light source is not relevant
- H05B47/20—Responsive to malfunctions or to light source life; for protection
- H05B47/23—Responsive to malfunctions or to light source life; for protection of two or more light sources connected in series
Definitions
- light strings are for decoration and display purposes, particularly during Christmas and other holidays, and more particularly for the decoration of Christmas trees, and the like.
- Probably the most popular light set currently available on the market, and in widespread use comprises one or more strings of fifty miniature light bulbs each, with each bulb typically having an operating voltage rating of 2.5 volts, and whose filaments are connected in an electrical series circuit arrangement. If overall sets of more than fifty bulbs are desired, the common practice is to provide a plurality of fifty miniature bulb strings, with the bulbs in each string connected in electrical series, and with the plurality of strings being connected in a parallel circuit arrangement.
- each bulb of each string is connected in series, when a single bulb fails to illuminate for any reason, the whole string fails to light and it is very frustrating and time consuming to locate and replace a defective bulb or bulbs.
- Usually many bulbs have to be checked before finding the failed bulb.
- the frustration and time consuming efforts are so great as to cause one to completely discard and replace the string with a new string before they are even placed in use.
- the problem is even more compounded when multiple bulbs simultaneously fail to illuminate for multiple reasons, such as, for example, one or more faulty light bulbs, one or more unstable socket connections, or one or more light bulbs physically fall from their respective sockets, and the like.
- Patent 4,450,382 utilizes a Zener diode connected in parallel with each series connected direct- current lamp used by trucks and other vehicles, particularly military trailers, for burn-out protection for the remaining bulbs whenever one or more bulbs burns out for some reason. It is stated therein that the use of either a single or a plurality of parallel connected
- Zener diodes will not protect the lamps against normal failure caused by normal current flows, but will protect against failures due to excessive current surges associated with the failure of associated lamps. No suggestion appears therein of any mechanism or technique which would provide a solution to the problem successfully achieved by applicant in a very simple and economica1 manner.
- shunts cause a reduced current flow in the series string because of too high of a voltage drop occurring across the shunt when a bulb becomes inoperable, either due to an open filament, a faulty bulb, a faulty socket, or simply because the bulb is not mounted properly in the socket, or is entirely removed or falls from its respective socket.
- other shunt devices cause the opposite effect due to an undesired increase in current flow. For example, when the voltage dropped across a socket decreases, then a higher voltage is applied to all of the remaining bulbs in the string, which higher voltage results in higher current flow and a decreased life expectancy of the remaining bulbs in the string.
- Fleck provided a bypass circuit across each halogen filled bulb which comprised a silicon bilateral voltage triggered switch in series with a diode which rectifies the alternating current (i.e., "A.C.") supply voltage and thereby permits current to flow through the bilateral switch only half of the time, i.e., only during each half cycle of the A.C. supply voltage. It is stated in Fleck that when a single bulb burns out, the remaining bulbs will have "diminished" light output because the diode will almost halve the effective voltage due to its blocking flow in one direction and conduction flow only in the opposite direction.
- A.C. alternating current
- Harnden proposes to utilize a polycrystalline metal oxide varistor as the shunting device, notwithstanding the fact that it is well known that metal oxide varistors are not designed to handle continuous current flow therethrough. Consequently, they are merely a so-called “one-shot” device for protective purposes, i.e. a transient voltage suppressor that is intended to absorb high frequency or rapid voltage spikes and thereby preventing such voltage spikes from doing damage to associated circuitry. They are designed for use as spike absorbers and are not designed to function as a voltage regulator or as a steady state current dissipation circuit. While metal oxide varistors may appear in some cases similar to back-to-back Zener diodes, they are not interchangeable and function very differently according to their particular use. In fact, the assignee of the assigne of the assigne of the assigne of the assigne of the assigne of the assigne of the assigne of the assigne of the assigne of the assigne of the assigne of the assigne of the assigne of the assigne of the assigne of
- Harnden '966 patent which was formerly General Electric Corporation and now is apparently Harris Semiconductor, Inc., states in their Application Note 9311: "They are exceptional at dissipating transient voltage spikes but they cannot dissipate continuous low level power.” In fact, they further state that their metal oxide varistors cannot be used as a voltage regulator as their function is to be used as a nonlinear impedance device.
- the only similarity that one can draw from metal oxide varistors and back-to-back Zener diodes is that they are both bi ⁇ directional; after that, the similarity ends.
- varistors preferably have a rating of 125% of that of the bulb rating and that such rating would result in a "decreased stress" across the remaining bulbs in the series string. Properly interpreted, this so-called decreased stress results in a loss of illumination in the remaining bulbs. For example, in a 50 bulb string operating at 120 volts A.C, each bulb receives an average voltage of 2.4 volts rms ("root mean square") or 3.39 peak volts. Since the varistor responds to the peak voltage, the varistor rating of 125% would be 4.24 volts, equivalent to 3.0 volts rms.
- Dyre discloses a bilateral shunt device having a breakdown voltage rating that, when exceeded, lowers the resistance thereof to 1 ohm, or less. This low value of resistance results in a substantial increase in the voltage being applied to the remaining bulbs even when only a single bulb is inoperative for any of the reasons previously stated. Thus, when multiple bulbs are inoperative, a still greater voltage is applied to the remaining bulbs, thereby again substantially increasing their illumination, and consequently, substantially shortening their life expectancy.
- miniature Christmas tree type lights now rely solely upon a specially designed bulb which is supposed to short out when becoming inoperative. Obviously, such a scheme is not always effective, particularly when a bulb is removed from its socket or becomes damaged in handling, etc.
- the extent of the extreme attempts made by others to absolutely keep the bulbs from falling from their sockets includes the use of a locking groove formed on the inside circumference of the socket mating with a corresponding raised ridge formed on the base of the bulb base unit. While this particular locking technique apparently is very effective to keep bulbs from falling from their respective sockets, the replacement of defective bulbs by the average user is extremely difficult, if not sometimes impossible, without resorting to mechanical gripping devices which can actually destroy the bulb base unit or socket .
- a novel filament shunting circuit for use in connection with a series connected string of incandescent light bulbs which completely overcomes in a very simple, novel and economical manner the problems heretofore associated with prior arrangements which were primarily designed to merely maintain some sort of current flow through the entire string of bulbs whenever one or more bulbs in the string becomes inoperable, either due to an open filament, one or more faulty bulbs, one or more faulty sockets, or simply because one or more of the bulbs are not properly mounted in their respective sockets, or are entirely removed or fall from their respective sockets.
- a series string of incandescent light bulbs each having a silicon type shunting device connected thereacross which has a predetermined voltage switching value which is greater than the voltage normally applied to said bulbs, and which shunt becomes fully conductive only when the peak voltage applied thereacross exceeds its said predetermined voltage switching value, which occurs whenever a bulb in the string either becomes inoperable due to any one or more or all of the following reasons: an open filament, faulty or damaged bulb, faulty socket, or simply because the bulb is not properly mounted in its respective socket, or is entirely removed or falls from its respective socket, and which circuit arrangement provides for the continued flow of rated current through all of the remaining bulbs in the string, together with substantially unchanged illumination in light output from any of those remaining operative in the string even though a substantial number of total bulbs in the string are simultaneously inoperative for any combinations of the various reasons heretofore stated.
- Figure 1 is an electrical schematic diagram of a novel light string constructed in accordance with a first embodiment of the present invention
- Figure 2 is an electrical schematic diagram of a novel light string constructed in accordance with a further embodiment of the present invention.
- Figure 3 is an electrical schematic diagram of a novel light string constructed in accordance with still another embodiment of the present invention.
- Figure 4 is an electrical schematic diagram of a novel light string constructed in accordance with still another embodiment of the present invention.
- the novel light string constructed in accordance with the first embodiment of the present invention comprises input terminals 10 and 11 which are adapted to be connected to a suitable source of supply of 110/120 volts of alternating current normally found in a typical household or business.
- Terminal 10 is normally fixedly connected to the first terminal of the first socket having a first electrical light bulb 12 operatively plugged therein.
- the adjacent terminal of the first socket is electrically connected to the adjacent terminal of the second socket having a second light bulb 13 operatively plugged therein, and so on, until each of the light bulbs in the entire string (whether a total of 10 bulbs, as diagrammatically shown, or a total of 50 as is typically the case) are finally operatively connected in an electrical series circuit between input terminals 10 and 11.
- first voltage sensitive switch 22 Operatively connected in electrical parallel across the electrical terminals of the first socket, hence the electrical terminals of first light bulb 12, is a first voltage sensitive switch 22 which is symbolically illustrated and which effectively functions as a first voltage regulating device in the manner hereinafter described.
- second voltage sensitive switch 23 operatively connected in electrical parallel across the electrical terminals of the second socket, hence second light bulb 13, is a second voltage sensitive switch 23 which likewise effectively functions as a voltage regulating device, and so on, until each of the remaining sockets, and hence each of remaining light bulbs 14 through 21 of the series has a corresponding one of voltage sensitive switches 24 through 31 operatively connected in parallel thereacross.
- all voltage responsive switches 22 through 31 be of identical construction and ideally would have a characteristic, such that, when conductive, i.e. in an "on” or “closed” condition, the impedance thereof have a value equal to the impedance of the filament of the corresponding light bulb and, when nonconductive, i.e. in an "off” or “open” condition, the value of the impedance thereof would be equal to infinity.
- Zener diodes when two well-known semiconductive devices known as "Zener” diodes are connected back-to-back (i.e. in an inverse electrical series connection) , they provide the desirable characteristics for an excellent voltage responsive switch which essentially functions as a voltage regulating device in accordance with the present invention, particularly since such back-to-back Zener diodes are readily available in the market place at relatively low cost, and more particularly when purchased in relatively large quantities.
- the mode of operation of the embodiment of Figure 1 is as follows: Assuming the light string is a typical 50 light string containing 50 lamps connected in electrical series, and with each lamp having a voltage rating of 2.4 volts, the effective voltage rating for the entire string would be determined by multiplying 50 times 2.4 volts, which resultant product equals 120 volts.
- the voltage across each individual lamp By electrically connecting two Zener diodes in a back-to-back inverse- series connection, with each having a voltage rating of 3.3 volts, across each lamp (which Zener diodes may both be constructed within the socket itself) , the voltage across each individual lamp, with 200 milliamperes of current flow, cannot increase beyond approximately 4.5 volts.
- the voltage across that particular lamp is approximately 2.4 volts (or approximately 3.4 volts, peak value) , depending, of course, on the value of the applied line voltage at that particular time.
- the voltage across that particular lamp is approximately 2.4 volts (or approximately 3.4 volts, peak value) , depending, of course, on the value of the applied line voltage at that particular time.
- two Zener diodes each having a voltage rating of 3.3 volts connected in a back-to-back configuration across each lamp, substantially no current flows through either of the Zener diodes, and substantially all of the current flows through each series connected lamp.
- the unusual and desirable characteristics of the foregoing embodiment over prior art light strings is the fact that the string continues to stay lit, regardless of whether one or more of the light bulbs in the string burns out, falls out of their respective sockets, or are loose or are inserted crooked in their respective sockets.
- the string stays lit no matter what happens to one or more light bulbs in the string.
- the back-to-back Zener diodes insure that current will continue to flow in the series- wired circuit, regardless of what happens to the particular light bulb across which it is shunted.
- each Zener diode when it was stated above that the voltage rating of each Zener diode is 3.3 volts, this means that the Zener diode will begin conducting in the reverse direction whenever the voltage across that particular Zener diode first reaches 3.3 volts. Conversely, when the Zener diode is conducting in the forward direction, there is an approximately .7 volt drop across that particular Zener diode.
- the effective voltage breakdown rating of the pair (hereinafter "effective voltage rating") is approximately 4.0 volts (i.e., 3.3 volts plus .7 volts) because one Zener diode in a pair is conducting in a forward direction and the other Zener diode in the pair is conducting in the reverse direction.
- the pair is polarity symmetrical, i.e., the same in both directions.
- This 4.0 voltage value will increase as more current flows through the back-to-back pair, until a current flow of approximately 200 milliamperes is flowing therethrough, i.e., the average current in a 50 bulb string, at which time the voltage dropped across the two 3.3 volt rated back-to-back Zener diodes reaches approximately 4.4 volts.
- Such back-to-back Zener diodes are commercially available from ITT Semiconductor Company as their DZ89 Series "dual Zeners" .
- Various voltage ratings are available and which ratings are usually expressed in terms of peak voltage values, or sometimes the A.C. rating.
- Each back-to-back Zener diode pair, or dual Zeners, is prevented from destroying itself as a result of the well-known "current runaway" condition, due to the current limiting effect by the remaining series connected lamps in the string whose total resistance value determines the magnitude of the current flowing therethrough. If, for example, all of the lamps are removed from the string, the supply voltage of 120 volts (A.C) , or 170 volts (peak) appears across the 50 shunts. With each back-to-back Zener diode shunt effectively rated at 4.0 volts (peak) , there is little or no current conduction in the string because only 3.4 volts (peak) is available to appear across each shunt.
- FIG. 1 Another preferred device is the bilateral silicon trigger switch (STS) , HS Series, which is currently available from Teccor Electronics, Inc., a Siebe Company, but is presently slightly more expensive than the back-to-back Zener type switch.
- STS bilateral silicon trigger switch
- HS Series type switches offer low breakover voltages, is mounted in an economical DO-35 package, and with glass-passivated junctions for reliability.
- the "HS” devices switch from the blocking mode to a conduction mode when the applied voltage, of either polarity, exceeds the breakover voltage and are not only bilateral but, like the back-to- back Zener diodes, are also very symmetrical for alternating current applications.
- each of the illustrated bilateral silicon trigger switches 22' through 31' is respectively connected in parallel with a corresponding one of series connected light bulbs 12 through 21 in the same manner as previously illustrated in Figure 1.
- the mode of operation of the silicon trigger switch embodiment shown in Figure 2 is substantially the same as that of the back-to-back Zener diode embodiment shown in Figure 1.
- substantially the same voltage drop of approximately 2.4 volts again appear across each light socket of a 50 miniature light string whenever the STS is conductive.
- the voltage across the STS device in a 50 light string at 200 milliamperes, at which most 50 light strings operate is approximately 2.4 volts, the same as it was when the respective light bulb was in its socket and operative.
- the voltage drop across each light bulb remains virtually unchanged, whether or not one or more of the remaining light bulbs in the string are operative.
- Another advantage of the STS embodiment is that it is not necessary to remove a shunt from one of the sockets in order to obtain either the desired "twinkling” or “twinkle-flash” operation.
- removal of the STS shunt from one of the sockets preferably one that is closest to the A.C socket, is necessary.
- the string will twinkle and flash. Flashing of the twinkling string will occur when at least twelve to thirteen bulbs are all simultaneously in an "off" state. This is because the STS devices switch to the conducting state when the voltage across them reach approximately 10 volts. Therefore, in a 120 volt supply line, it will take twelve to thirteen lamps to be in the "off" state before the string goes out. When the flashers return to their normal conducting state, the string comes on again and twinkles until twelve to thirteen bulbs are again simultaneously in an "off” state.
- the periodicity of this flashing "off” and “on” will be a function of the flasher bulbs. If the flasher bulbs are illuminated most of the time and are only “off” for a short period of time, to have the twelve to thirteen simultaneously “off” will be infrequent and will result in a shorter time period of flashing and in a longer time period of twinkling.
- the embodiment shown in Figure 3 illustrates a circuit arrangement which operates substantially the same as the previous embodiments, with the exception that the source of operating voltage is a full wave rectified voltage which pulsates at twice the normal 60 cycle rate. As shown in Figure 3, STS devices 22" through 31" are respectively shunted across light bulbs 12-21, which preferably comprises a 50 miniature bulb string.
- a full wave rectifier 9 which preferably has a 3.9 microfarad capacitor connected across terminals 6 and 7.
- the rectifier 9 and capacitor 8 can either be installed inside the A.C plug or they can be in a separate adapter plug that the power cord plug is plugged into. This will apply pulsating and partially filtered direct current (i.e., "D.C") to the string. Direct current is needed to prevent the STS devices from switching "off” during the time a flasher bulb is in the "off” state, since the voltage never reaches zero volts to turn the device "off".
- D.C direct current
- the STS device is triggered “off” and "on” 120 times a second.
- a voltage of approximately 10 volts is required to turn it on. This is the reason for the limitation on the number of bulbs that can twinkle using an A.C. source of operating potential.
- D.C. as the operating potential
- the STS devices remain conductive until the associated flasher bulb is illuminated. Therefore, there is no limitation on the number of bulbs that can be used in the string. While there is no limitation on the number of bulbs that can twinkle in a string using D.C. voltage as the operating potential, there is another matching consideration which preferably should be addressed.
- the string will function the same as if A.C were used as the operating potential. This is because the STS device will go "off" and "on” 120 times a second, i.e., two times the A.C. rate.
- the STS device will go "off" and "on” 120 times a second, i.e., two times the A.C. rate.
- capacitor 8 By installing a capacitor across the output of the bridge rectifier, there will be an improvement in performance. However, if capacitor 8 is too small, the lamp intensity will flicker, especially if flasher bulbs are mixed with regular bulbs in the string. Additionally, the current in the string will be too low. If too large of a capacitor is used, the current through the bulbs will be excessive and bulb life will be shortened.
- the ideal capacitance is one where the current through the lamps is the normal 200 milliamperes in a typical 50 miniature light bulb string. At this level, current flow stabilizes and the string operates perfectly. In a 50 miniature bulb string, the preferred capacitance is approximately 3.3 to 4.7 microfarads. If one or more flasher bulbs are now inserted into the string, each flasher bulb will continue to go "on" and
- FIG 4 there is illustrated a circuit arrangement which operates substantially the same as the previously described embodiments, with the exception that only a single Zener diode is shunted across each bulb socket and that preferably one-half of the total number of Zener diodes in the circuit are functionally oriented in one predetermined direction, as illustrated by light bulbs 12 through 16, while the remaining half are functionally oriented in the opposite direction, as illustrated by light bulbs 17 through 21.
- each bulb receives an average rms voltage of approximately 2.4 volts, or approximately 3.4 peak volts, if all of the bulbs are of the same rating, which is normally the case.
- the average voltage drop across each bulb is approximately 120 divided by 50, or approximately 2.4 volts rms or 3.4 peak volts. This is because during one-half of the A.C.
- the first 25 shunts will be forward biased and approximately .7-.8 peak volts will appear across each shunt for a total of approximately 17.5-20 volts peak dropped across the first 25 shunts.
- Bulbs placed in these particular sockets will each receive a voltage of approximately .7-.8 peak volts during the first half cycle of the operating potential, thereby resulting in a momentary tendency to decrease in brightness output.
- the average voltage dropped across each bulb during one complete positive and negative alternating cycle is approximately 3.4 peak volts, or 6.8 volts peak-to-peak which corresponds to the rating of the particular bulbs used in the series string. This is because, while the peak voltage in both cases are the same, the effective voltages are not.
- the wave form is sinusoidal, while in the Zener diode shunt case, the alternating wave form is one-half sine wave and one-half square wave. The half that is sine wave is approximately 6.2 volts (peak) , while the remaining half is square wave, is approximately .7 volts (peak) .
- Zener diode From strictly a manufacturing cost standpoint, it is estimated that a single Zener diode would cost approximately 2.0 cents in mass quantities, that the cost of back-to-back Zener diodes would be approximately 2.3 cents each, and that the cost of the HS-10 bilateral silicon switch would be approximately 5.0 cents.
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- Circuit Arrangement For Electric Light Sources In General (AREA)
Abstract
Description
Claims
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP9542312A JPH11509974A (en) | 1996-05-28 | 1997-02-03 | Series connected light source string with filament shunt |
DE19781744A DE19781744B4 (en) | 1996-05-28 | 1997-02-03 | Series connected fairy lights with filament resistance |
DE19781744T DE19781744T1 (en) | 1996-05-28 | 1997-02-03 | Light chain connected in series with filament shunt resistor |
GB9823170A GB2327307B (en) | 1996-05-28 | 1997-02-03 | Series connected light string with filament shunting |
CA002255641A CA2255641C (en) | 1996-05-28 | 1997-02-03 | Series connected light string with filament shunting |
HK99102133A HK1017226A1 (en) | 1996-05-28 | 1999-05-12 | Series connected light string with filament shunting |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US65397996A | 1996-05-28 | 1996-05-28 | |
US08/653,979 | 1996-05-28 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1997046055A1 true WO1997046055A1 (en) | 1997-12-04 |
Family
ID=24623040
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1997/001831 WO1997046055A1 (en) | 1996-05-28 | 1997-02-03 | Series connected light string with filament shunting |
Country Status (7)
Country | Link |
---|---|
JP (1) | JPH11509974A (en) |
CN (1) | CN1220076A (en) |
CA (1) | CA2255641C (en) |
DE (2) | DE19781744T1 (en) |
GB (1) | GB2327307B (en) |
HK (1) | HK1017226A1 (en) |
WO (1) | WO1997046055A1 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1999053729A1 (en) * | 1998-04-10 | 1999-10-21 | Stay Lit International, Inc. | Series connected light string with filament shunting |
EP0989026A3 (en) * | 1998-09-22 | 2003-07-16 | Diehl Stiftung & Co. | Aircraft cabin lighting |
US6597125B2 (en) | 2001-05-17 | 2003-07-22 | Jlj, Inc. | Voltage regulated light string |
US7178961B2 (en) | 1995-06-26 | 2007-02-20 | Jlj, Inc. | Voltage regulated light string |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7564666B2 (en) * | 2006-05-02 | 2009-07-21 | Semiconductor Components Industries, L.L.C. | Shunt protection circuit and method therefor |
US7976191B2 (en) * | 2006-10-02 | 2011-07-12 | Best Point Group, Ltd. | Light string of LEDs |
US8247999B2 (en) * | 2008-01-22 | 2012-08-21 | Alcatel Lucent | Time division multiplexing a DC-to-DC voltage converter |
GB2509099A (en) * | 2012-12-20 | 2014-06-25 | Accuric Ltd | LED driver circuit |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CH427021A (en) * | 1964-07-03 | 1966-12-31 | Danfoss As | Device for compensating for the failure of a series resistor when connected in series, in particular when lighting a Christmas tree |
US3912966A (en) * | 1973-04-30 | 1975-10-14 | Gen Electric | Incandescent lamp series string having protection against voltage surges |
Family Cites Families (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1024495A (en) * | 1910-10-26 | 1912-04-30 | Edgar Booth | Electric-lighting system. |
US2072337A (en) * | 1936-05-05 | 1937-03-02 | Nofade Electric Corp | Safety lighting circuit |
FR884370A (en) * | 1942-03-17 | 1943-08-11 | Improvements in the supply of electrical devices | |
US2760120A (en) * | 1955-10-26 | 1956-08-21 | New York Merchandise Co Inc | Lighting system for christmas trees |
US3639805A (en) * | 1970-05-25 | 1972-02-01 | Gen Motors Corp | Series lamp safeguard circuit |
US4450382A (en) * | 1982-06-21 | 1984-05-22 | The United States Of America As Represented By The Secretary Of The Army | D.C. Lamp burn-out protection |
US4682079A (en) * | 1984-10-04 | 1987-07-21 | Hallmark Cards, Inc. | Light string ornament circuitry |
US4727449A (en) * | 1986-10-01 | 1988-02-23 | Chiu Technical Corporation | Filament bypass circuit |
US5006724A (en) * | 1989-03-20 | 1991-04-09 | Liu Ching Chung | Control device for light sets |
FR2663183B1 (en) * | 1990-06-07 | 1997-04-11 | Fd Eclairage Architectural | LOW VOLTAGE LAMP SUPPLY CIRCUIT ARRANGED IN SERIES. |
EP0576536B1 (en) * | 1991-02-27 | 2001-12-12 | Roche Diagnostics Corporation | Method of communicating with microcomputer controlled instruments |
US5539317A (en) * | 1994-11-07 | 1996-07-23 | Jlj, Inc. | Circuit tester for Christmas tree light sets |
-
1997
- 1997-02-03 DE DE19781744T patent/DE19781744T1/en active Pending
- 1997-02-03 JP JP9542312A patent/JPH11509974A/en active Pending
- 1997-02-03 CA CA002255641A patent/CA2255641C/en not_active Expired - Fee Related
- 1997-02-03 WO PCT/US1997/001831 patent/WO1997046055A1/en active Application Filing
- 1997-02-03 CN CN97195011A patent/CN1220076A/en active Pending
- 1997-02-03 DE DE19781744A patent/DE19781744B4/en not_active Expired - Fee Related
- 1997-02-03 GB GB9823170A patent/GB2327307B/en not_active Expired - Fee Related
-
1999
- 1999-05-12 HK HK99102133A patent/HK1017226A1/en not_active IP Right Cessation
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CH427021A (en) * | 1964-07-03 | 1966-12-31 | Danfoss As | Device for compensating for the failure of a series resistor when connected in series, in particular when lighting a Christmas tree |
US3912966A (en) * | 1973-04-30 | 1975-10-14 | Gen Electric | Incandescent lamp series string having protection against voltage surges |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7178961B2 (en) | 1995-06-26 | 2007-02-20 | Jlj, Inc. | Voltage regulated light string |
WO1999053729A1 (en) * | 1998-04-10 | 1999-10-21 | Stay Lit International, Inc. | Series connected light string with filament shunting |
GB2352099A (en) * | 1998-04-10 | 2001-01-17 | Stay Lit Internat Inc | Series connected light string with filament shunting |
GB2352099B (en) * | 1998-04-10 | 2002-07-10 | Stay Lit Internat Inc | Series connected light string with filament shunting |
EP0989026A3 (en) * | 1998-09-22 | 2003-07-16 | Diehl Stiftung & Co. | Aircraft cabin lighting |
US6597125B2 (en) | 2001-05-17 | 2003-07-22 | Jlj, Inc. | Voltage regulated light string |
Also Published As
Publication number | Publication date |
---|---|
GB2327307A (en) | 1999-01-20 |
DE19781744T1 (en) | 1999-05-12 |
GB2327307B (en) | 2000-02-16 |
CN1220076A (en) | 1999-06-16 |
GB9823170D0 (en) | 1998-12-16 |
HK1017226A1 (en) | 1999-11-12 |
JPH11509974A (en) | 1999-08-31 |
CA2255641C (en) | 2002-06-25 |
DE19781744B4 (en) | 2006-03-02 |
CA2255641A1 (en) | 1997-12-04 |
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