US3639805A - Series lamp safeguard circuit - Google Patents
Series lamp safeguard circuit Download PDFInfo
- Publication number
- US3639805A US3639805A US40184A US3639805DA US3639805A US 3639805 A US3639805 A US 3639805A US 40184 A US40184 A US 40184A US 3639805D A US3639805D A US 3639805DA US 3639805 A US3639805 A US 3639805A
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- United States
- Prior art keywords
- lamp
- breakdown
- headlamp
- circuit
- parallel
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- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60Q—ARRANGEMENT OF SIGNALLING OR LIGHTING DEVICES, THE MOUNTING OR SUPPORTING THEREOF OR CIRCUITS THEREFOR, FOR VEHICLES IN GENERAL
- B60Q11/00—Arrangement of monitoring devices for devices provided for in groups B60Q1/00 - B60Q9/00
Definitions
- ABSTRACT A vehicle-headlamp-energizing circuit for headlamps connected in series. Each headlamp has a breakdown diode connected in parallel, and each breakdown diode has a breakdown voltage slightly larger than the normal potential drop across its parallel connected lamp so as to conduct current around the lamp when it fails and maintain conduction through the remaining lamps.
- the FIGURE is a circuit diagram of a preferred embodiment of our invention.
- Our lamp circuit contains headlamps l0, 12 connected in series with headlamp switch 14 across battery 16. Connected across each headlamp is a breakdown or zener diode 20, 22.
- Each breakdown diode has an intrinsic breakdown voltage associated with it such that the breakdown diode presents an extremely large resistance to voltages below this breakdown voltage and an extremely small resistance to voltages greater than the breakdown voltage.
- the value of the breakdown voltage of each breakdown diode in this circuit is slightly larger than the normal operating voltage of the headlamp across which it is connected. For instance, if the battery potential is 12 volts and each lamp normally drops 6 volts the breakdown voltage of each diode would be approximately 7 volts. Thus, neither of the breakdown diodes 20, 22 would normally conduct more than negligible current.
- circuit described is the simplest embodiment of our invention, but many variations are possible. Any number of lamps of the proper voltage ratings, each with accompanying diode could be added in series. Lamps of different voltage ratings could be combined, provided the breakdown voltage of each diode was just larger than the operating voltage of the lamp across which it is connected.
- lamps other than headlamps for example, tail lamps, instrument panel lights, or side marker lamps on trucks and trailers.
- An electriclamp circuit comprising, in combination, a source of current at substantially constant potential, a plural number of electric lamps connected in series across the source, and a plural number of zener breakdown diodes, one of which is connected in parallel with each lamp, each breakdown diode having a breakdown voltage slightly greater than the voltage drop in normal operation of its parallel lamp, so that each breakdown diode is substantially nonconducting but will conduct upon failure of its parallel lamp and maintain the energizing circuit to the remaining lamp or lamps.
- a vehicle headlamp energizing circuit comprising a plurality of headlamps connected in series with a battery, each lamp having a normal potential drop across it while operating,
- each lamp havin a zener breakdown diode connected in parallel with it, e breakdown diode having a breakdown voltage slightly greater than the normal potential drop of its parallel headlamp so as to conduct current around the headlamp only when the headlamp fails.
- a circuit as defined in claim 2 in which only two headlamps are connected in series with the battery in the said circuit.
Abstract
A vehicle-headlamp-energizing circuit for headlamps connected in series. Each headlamp has a breakdown diode connected in parallel, and each breakdown diode has a breakdown voltage slightly larger than the normal potential drop across its parallel connected lamp so as to conduct current around the lamp when it fails and maintain conduction through the remaining lamps.
Description
United States Patent Muench et al.
154] SERIES LAMP SAFEGUARD CIRCUIT [72] Inventors: Nils L. Muench, Bloomfield Hills; Charles B. Murphy, Fraser, both of Mich.
General Motors Corporation, Detroit, Mich.
[22] Filed: May 25,1970
[21] Appl.No.: 40,184
[73] Assignee:
[52] U.S.Cl. ..3l5/l22,3l5/82,315/l85 R [51] Int. Cl. ..H05b 37/00 [58] Field oiSearch ..315/74,75,82,83,122,123,
[56] References Cited UNITED STATES PATENTS 1 Feb. 1,1972
FOREIGN PATENTS OR APPLICATIONS 427,021 6/1967 Switzerland ..3 15/122 Primary Examiner-Raymond F. l-lossfeld Attorney-J. L. Carpenter and Paul Fitzpatrick [57] ABSTRACT A vehicle-headlamp-energizing circuit for headlamps connected in series. Each headlamp has a breakdown diode connected in parallel, and each breakdown diode has a breakdown voltage slightly larger than the normal potential drop across its parallel connected lamp so as to conduct current around the lamp when it fails and maintain conduction through the remaining lamps.
7 4 Claims, 1 Drawing Figure s i Q SERIES LAMP SAFEGUARD CIRCUIT The conventional automotive vehicle headlamp system has headlamps connected in parallel across a battery. This is necessary so that if one lamp malfunctions and does not conduct current the other lamp will not be affected.
However, there are often advantages to be gained by connecting headlamps in series. Without changing the battery voltage, for example, two headlamps of one-half rated battery voltage can be used. These lower voltage lamps are more rugged and function longer, on the average, than higher voltage lamps. Or, if the battery voltage itself were doubled to reduce current loads in the rest of the vehicles electrical system, the two conventional voltage headlamps could be used in series rather than double voltage lamps in parallel.
The main problem with series connected lamps is, as said,
' that if one lamp stops conducting because of a broken or oxidized filament the other is prevented from conducting by the break in the circuit. We will disclose, however, a simple, inexpensive and reliable circuit which contains lamps connected in series but which keeps the unaffected lamp shining should the other burn out or break.
The FIGURE is a circuit diagram of a preferred embodiment of our invention.
Our lamp circuit contains headlamps l0, 12 connected in series with headlamp switch 14 across battery 16. Connected across each headlamp is a breakdown or zener diode 20, 22. Each breakdown diode has an intrinsic breakdown voltage associated with it such that the breakdown diode presents an extremely large resistance to voltages below this breakdown voltage and an extremely small resistance to voltages greater than the breakdown voltage. The value of the breakdown voltage of each breakdown diode in this circuit is slightly larger than the normal operating voltage of the headlamp across which it is connected. For instance, if the battery potential is 12 volts and each lamp normally drops 6 volts the breakdown voltage of each diode would be approximately 7 volts. Thus, neither of the breakdown diodes 20, 22 would normally conduct more than negligible current.
Suppose, however, that lamp l burns out or breaks so that the circuit opens. At once the voltage across the open circuit attempts to rise to battery potential. However, that voltage is also the voltage across breakdown diode and when it reaches 7 volts diode 20 begins to conduct. Since the breakdown diode 20 can conduct large amounts of current at approximately 7 volts the potential across the other headlamp 12 will not fall below 5 volts. Headlamp 12 will dim slightly but will remain shining. In the same way breakdown diode 22 will conduct to keep headlamp l0 shining should headlamp l2 fail.
The circuit described is the simplest embodiment of our invention, but many variations are possible. Any number of lamps of the proper voltage ratings, each with accompanying diode could be added in series. Lamps of different voltage ratings could be combined, provided the breakdown voltage of each diode was just larger than the operating voltage of the lamp across which it is connected.
Obviously, the same type of circuit connection may be used with lamps other than headlamps; for example, tail lamps, instrument panel lights, or side marker lamps on trucks and trailers.
We claim:
1. An electriclamp circuit comprising, in combination, a source of current at substantially constant potential, a plural number of electric lamps connected in series across the source, and a plural number of zener breakdown diodes, one of which is connected in parallel with each lamp, each breakdown diode having a breakdown voltage slightly greater than the voltage drop in normal operation of its parallel lamp, so that each breakdown diode is substantially nonconducting but will conduct upon failure of its parallel lamp and maintain the energizing circuit to the remaining lamp or lamps.
2. A vehicle headlamp energizing circuit comprising a plurality of headlamps connected in series with a battery, each lamp having a normal potential drop across it while operating,
each lamp havin a zener breakdown diode connected in parallel with it, e breakdown diode having a breakdown voltage slightly greater than the normal potential drop of its parallel headlamp so as to conduct current around the headlamp only when the headlamp fails.
3. A circuit as defined in claim 2 in which only two headlamps are connected in series with the battery in the said circuit.
4. A circuit as defined in claim 3 in which the battery is a power source of substantially X volts and the breakdown diodes have a breakdown voltage slightly greater than one-half X volts whereby failure of a headlamp causes the diode in parallel therewith to conduct so as to effect a voltage drop of slightly less than one-half X volts across the headlamp which remains energized.
Claims (4)
1. An electric lamp circuit comprising, in combination, a source of current at substantially constant potential, a plural number of electric lamps connected in series across the source, and a plural number of zener breakdown diodes, one of which is connected in parallel with each lamp, each breakdown diode having a breakdown voltage slightly greater than the voltage drop in normal operation of its parallel lamp, so that each breakdown diode is substantially nonconducting but will conduct upon failure of its parallel lamp and maintain the energizing circuit to the remaining lamp or lamps.
2. A vehicle headlamp energizing circuit comprising a plurality of headlamps connected in series with a battery, each lamp having a normal potential drop across it while operating, each lamp having a zener breakdown diode connected in parallel with it, the breakdown diode having a breakdown voltage slightly greater than the normal potential drop of its parallel headlamp so as to conduct current around the headlamp only when the headlamp fails.
3. A circuit as defined in claim 2 in which only two headlamps are connected in series with the battery in the said circuit.
4. A circuit as defined in claim 3 in which the battery is a power source of substantially X volts and the breakdown diodes have a breakdown voltage slightly greater than one-half X volts whereby failure of a headlamp causes the diode in parallel therewith to conduct so as to effect a voltage drop of slightly less than one-half X volts across the headlamp which remains energized.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US4018470A | 1970-05-25 | 1970-05-25 |
Publications (1)
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US3639805A true US3639805A (en) | 1972-02-01 |
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US40184A Expired - Lifetime US3639805A (en) | 1970-05-25 | 1970-05-25 | Series lamp safeguard circuit |
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Cited By (34)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3912966A (en) * | 1973-04-30 | 1975-10-14 | Gen Electric | Incandescent lamp series string having protection against voltage surges |
JPS50161071A (en) * | 1974-06-17 | 1975-12-26 | ||
US3967257A (en) * | 1973-01-09 | 1976-06-29 | Westinghouse Electric Corporation | Current monitor circuits |
DE3230975A1 (en) * | 1982-08-20 | 1984-02-23 | Robert Bosch Gmbh, 7000 Stuttgart | MOTOR VEHICLE LAMP MADE OF LIGHT-EMITTING DIODES OR LIGHT-EMITTING DIODE CHIPS |
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 |
US4587457A (en) * | 1982-02-19 | 1986-05-06 | Minnesota Mining And Manufacturing Company | Multiple intensity lamp controller and lighting system |
US4912372A (en) * | 1988-11-28 | 1990-03-27 | Multi Electric Mfg. Co. | Power circuit for series connected loads |
US4928036A (en) * | 1987-11-23 | 1990-05-22 | General Motors Corporation | Vehicle headlamp system with series high beam daylight running lamp operation |
US5886423A (en) * | 1997-09-10 | 1999-03-23 | Leviton Manufacturing Co., Inc. | Electric series circuit |
US5962929A (en) * | 1998-04-22 | 1999-10-05 | Lockheed Martin Corporation | Fault tolerant power distribution |
WO2002093711A1 (en) * | 2001-05-17 | 2002-11-21 | Stay Lit International, Inc. | Voltage regulated light string |
WO2003030593A1 (en) * | 2001-09-29 | 2003-04-10 | Ye, Min | Fluorescent lamp capable of starting with at least one broken filament |
US6580182B2 (en) * | 1995-06-26 | 2003-06-17 | Jlj, Inc. | Series connected light string with filament shunting |
US20040229439A1 (en) * | 2003-05-16 | 2004-11-18 | Janning John L. | Method of fabricating a zener diode chip for use as a shunt in Christmas tree lighting |
US20050041423A1 (en) * | 1995-06-26 | 2005-02-24 | Janning John L. | DC series connected light string with diode array shunt |
US20050041422A1 (en) * | 1995-06-26 | 2005-02-24 | Janning John L. | Series connected light string with filament shunting |
US20050170629A1 (en) * | 2003-05-16 | 2005-08-04 | Janning John L. | Method of fabricating a low cost zener diode chip for use in shunt-wired miniature light strings |
US20050179400A1 (en) * | 1995-06-26 | 2005-08-18 | Janning John L. | Voltage regulated light string |
DE19781744B4 (en) * | 1996-05-28 | 2006-03-02 | Stay Lit International, Inc., Dayton | Series connected fairy lights with filament resistance |
US20060082223A1 (en) * | 1995-06-26 | 2006-04-20 | Janning John L | Christmas light string with single Zener shunts |
US20060145627A1 (en) * | 2005-01-03 | 2006-07-06 | Mei-Ling Peng | Continuous current control circuit modules of series string bulbs |
US20070075646A1 (en) * | 1995-06-26 | 2007-04-05 | Jlj, Inc. | Series wired light string with unidirectional shunts |
US7242148B2 (en) * | 2005-02-23 | 2007-07-10 | Mei-Ling Peng | Continuous current control circuit modules of series string bulbs type (II) |
US20080018260A1 (en) * | 1995-06-26 | 2008-01-24 | Jlj, Inc. | Series wired light string with unidirectional resistive shunts |
US20080129213A1 (en) * | 1995-06-26 | 2008-06-05 | Janning John L | Flasher bulbs with shunt wiring for use in series connected light string with filament shunting in bulb sockets |
US20080252220A1 (en) * | 1995-06-26 | 2008-10-16 | Jlj, Inc. | Series wired light string with shunts and flasher bulbs for exhibiting a twinkling effect |
DE19781679B4 (en) * | 1996-07-10 | 2008-12-04 | Solar Wide Industrial Ltd., Tsuen Wan | Solar outdoor lamp |
US20090039794A1 (en) * | 1995-06-26 | 2009-02-12 | Janning John L | Miniature light bulb for random high-low twinkle in series-wired light string |
US20090091263A1 (en) * | 2008-11-24 | 2009-04-09 | Janning John L | Capacitor shunted led light string |
US20090129077A1 (en) * | 1995-06-26 | 2009-05-21 | Jlj, Inc. | Series-wired led light string with unidirectional shunts |
US20100045186A1 (en) * | 2006-10-04 | 2010-02-25 | Janning John L | Dual brightness twinkle in a miniature light bulb |
US20100061025A1 (en) * | 2008-09-09 | 2010-03-11 | Parker Francis J | LED module for sign channel letters and driving circuit |
US20100109538A1 (en) * | 2005-02-23 | 2010-05-06 | Mei-Ling Peng | Continuous current control circuit modules of series string bulbs type |
US9554444B2 (en) | 2012-12-17 | 2017-01-24 | OV20 Systems | Device and method for retrofitting or converting or adapting series circuits |
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 |
US3535585A (en) * | 1968-09-12 | 1970-10-20 | Gen Motors Corp | Safety lamp circuit for serially connected vehicle lamps |
-
1970
- 1970-05-25 US US40184A patent/US3639805A/en not_active Expired - Lifetime
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 |
US3535585A (en) * | 1968-09-12 | 1970-10-20 | Gen Motors Corp | Safety lamp circuit for serially connected vehicle lamps |
Cited By (54)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3967257A (en) * | 1973-01-09 | 1976-06-29 | Westinghouse Electric Corporation | Current monitor circuits |
US3912966A (en) * | 1973-04-30 | 1975-10-14 | Gen Electric | Incandescent lamp series string having protection against voltage surges |
JPS50161071A (en) * | 1974-06-17 | 1975-12-26 | ||
JPS559159B2 (en) * | 1974-06-17 | 1980-03-07 | ||
US4587457A (en) * | 1982-02-19 | 1986-05-06 | Minnesota Mining And Manufacturing Company | Multiple intensity lamp controller and lighting system |
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 |
DE3230975A1 (en) * | 1982-08-20 | 1984-02-23 | Robert Bosch Gmbh, 7000 Stuttgart | MOTOR VEHICLE LAMP MADE OF LIGHT-EMITTING DIODES OR LIGHT-EMITTING DIODE CHIPS |
US4928036A (en) * | 1987-11-23 | 1990-05-22 | General Motors Corporation | Vehicle headlamp system with series high beam daylight running lamp operation |
US4912372A (en) * | 1988-11-28 | 1990-03-27 | Multi Electric Mfg. Co. | Power circuit for series connected loads |
US7391161B2 (en) | 1995-06-26 | 2008-06-24 | Jlj, Inc. | Series wired light string with unidirectional shunts |
US20060055250A1 (en) * | 1995-06-26 | 2006-03-16 | Janning John L | Christmas light string with silicon triggered switch shunts |
US20080129213A1 (en) * | 1995-06-26 | 2008-06-05 | Janning John L | Flasher bulbs with shunt wiring for use in series connected light string with filament shunting in bulb sockets |
US7342327B2 (en) | 1995-06-26 | 2008-03-11 | Jlj, Inc. | Series connected light string with filament shunting |
US6580182B2 (en) * | 1995-06-26 | 2003-06-17 | Jlj, Inc. | Series connected light string with filament shunting |
US7339325B2 (en) | 1995-06-26 | 2008-03-04 | Jlj, Inc. | Series wired light string with unidirectional resistive shunts |
US6765313B2 (en) * | 1995-06-26 | 2004-07-20 | Jlj, Inc. | Series connected light string with filament shunting |
US7732942B2 (en) | 1995-06-26 | 2010-06-08 | Jlj, Inc. | Flasher bulbs with shunt wiring for use in series connected light string with filament shunting in bulb sockets |
US20040246640A1 (en) * | 1995-06-26 | 2004-12-09 | Janning John L. | Series connected light string with filament shunting |
US20050041423A1 (en) * | 1995-06-26 | 2005-02-24 | Janning John L. | DC series connected light string with diode array shunt |
US20050041422A1 (en) * | 1995-06-26 | 2005-02-24 | Janning John L. | Series connected light string with filament shunting |
US20090129077A1 (en) * | 1995-06-26 | 2009-05-21 | Jlj, Inc. | Series-wired led light string with unidirectional shunts |
US20080018260A1 (en) * | 1995-06-26 | 2008-01-24 | Jlj, Inc. | Series wired light string with unidirectional resistive shunts |
US20050179400A1 (en) * | 1995-06-26 | 2005-08-18 | Janning John L. | Voltage regulated light string |
US7279809B2 (en) | 1995-06-26 | 2007-10-09 | Jlj, Inc. | Christmas light string with single Zener shunts |
US20080252220A1 (en) * | 1995-06-26 | 2008-10-16 | Jlj, Inc. | Series wired light string with shunts and flasher bulbs for exhibiting a twinkling effect |
US20060082223A1 (en) * | 1995-06-26 | 2006-04-20 | Janning John L | Christmas light string with single Zener shunts |
US7042116B2 (en) | 1995-06-26 | 2006-05-09 | Jlj, Inc. | Series connected light string with filament shunting |
US20090039794A1 (en) * | 1995-06-26 | 2009-02-12 | Janning John L | Miniature light bulb for random high-low twinkle in series-wired light string |
US7086758B2 (en) | 1995-06-26 | 2006-08-08 | Jlj, Inc. | Series connected light string with filament shunting |
US7166968B2 (en) | 1995-06-26 | 2007-01-23 | Jlj, Inc. | DC series connected light string with diode array shunt |
US20070029937A1 (en) * | 1995-06-26 | 2007-02-08 | Janning John L | Series connected light string with filament shunting |
US7178961B2 (en) * | 1995-06-26 | 2007-02-20 | Jlj, Inc. | Voltage regulated light string |
US20070075646A1 (en) * | 1995-06-26 | 2007-04-05 | Jlj, Inc. | Series wired light string with unidirectional shunts |
DE19781744B4 (en) * | 1996-05-28 | 2006-03-02 | Stay Lit International, Inc., Dayton | Series connected fairy lights with filament resistance |
DE19781679B4 (en) * | 1996-07-10 | 2008-12-04 | Solar Wide Industrial Ltd., Tsuen Wan | Solar outdoor lamp |
US5886423A (en) * | 1997-09-10 | 1999-03-23 | Leviton Manufacturing Co., Inc. | Electric series circuit |
US5962929A (en) * | 1998-04-22 | 1999-10-05 | Lockheed Martin Corporation | Fault tolerant power distribution |
US6597125B2 (en) | 2001-05-17 | 2003-07-22 | Jlj, Inc. | Voltage regulated light string |
WO2002093711A1 (en) * | 2001-05-17 | 2002-11-21 | Stay Lit International, Inc. | Voltage regulated light string |
WO2003030593A1 (en) * | 2001-09-29 | 2003-04-10 | Ye, Min | Fluorescent lamp capable of starting with at least one broken filament |
US20050170629A1 (en) * | 2003-05-16 | 2005-08-04 | Janning John L. | Method of fabricating a low cost zener diode chip for use in shunt-wired miniature light strings |
US6900093B2 (en) | 2003-05-16 | 2005-05-31 | Jlj, Inc. | Method of fabricating a zener diode chip for use as a shunt in Christmas tree lighting |
US20040229439A1 (en) * | 2003-05-16 | 2004-11-18 | Janning John L. | Method of fabricating a zener diode chip for use as a shunt in Christmas tree lighting |
US20060145627A1 (en) * | 2005-01-03 | 2006-07-06 | Mei-Ling Peng | Continuous current control circuit modules of series string bulbs |
US20100109538A1 (en) * | 2005-02-23 | 2010-05-06 | Mei-Ling Peng | Continuous current control circuit modules of series string bulbs type |
US7242148B2 (en) * | 2005-02-23 | 2007-07-10 | Mei-Ling Peng | Continuous current control circuit modules of series string bulbs type (II) |
US20100045186A1 (en) * | 2006-10-04 | 2010-02-25 | Janning John L | Dual brightness twinkle in a miniature light bulb |
US20100061025A1 (en) * | 2008-09-09 | 2010-03-11 | Parker Francis J | LED module for sign channel letters and driving circuit |
US20110085271A1 (en) * | 2008-09-09 | 2011-04-14 | Inshore Holdings, Llc | LED Modules for Sign Channel Letters and Driving Circuit |
US8305717B2 (en) | 2008-09-09 | 2012-11-06 | Inshore Holdings, Llc | LED modules for sign channel letters and driving circuit |
US8611057B2 (en) | 2008-09-09 | 2013-12-17 | Inshore Holdings, Llc | LED module for sign channel letters and driving circuit |
US20090091263A1 (en) * | 2008-11-24 | 2009-04-09 | Janning John L | Capacitor shunted led light string |
US8324820B2 (en) | 2008-11-24 | 2012-12-04 | Jlj, Inc. | Capacitor shunted LED light string |
US9554444B2 (en) | 2012-12-17 | 2017-01-24 | OV20 Systems | Device and method for retrofitting or converting or adapting series circuits |
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