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
  • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
• • 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
  • H05B44/00—Circuit arrangements for operating electroluminescent light sources
• • 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
  • H05B47/24—Circuit arrangements for protecting against overvoltage
• • 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
  • H05B47/25—Circuit arrangements for protecting against overcurrent
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
  • Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
  • Y02B20/30—Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Definitions

• the invention relates to an LED replacement lamp, and to a lighting arrangement including an LED replacement lamp.
• Fluorescent lamps in particular in the form of fluorescent tube lamps, are today used in many lighting applications. A large number of lighting fixtures for fluorescent tube lamps are installed.
• LED replacement lamps available intended to be used as “retrofit” or replacement LED lamps, replacing fluorescent lamps in installed lighting fixtures.
• WO 2009/136322 Al describes a light emitting system with a light emitting diode and a socket adapter for retrofitting a fluorescent lamp.
• An electrical circuit is adapted for emulating the presence of fluorescent lamps to a fluorescent lamp driver.
• the lamp according to the invention comprises one or more LED lighting elements arranged on an elongated member with a first end and opposite second end.
• LED is used broadly, covering all types of solid state lighting elements, including individual components as well as electrical circuits with multiple components, or groups of components, the components including both light emitting diodes (LED) and organic light emitting diodes (OLED).
• the elongated member may in particular be of a size corresponding to standardized fluorescent tube lamps, e. g. 205 mm, 325 mm, 355 mm, etc. and may comprise e. g. an at least partially transparent housing, particularly in tube form. At each of the opposite ends, two electrical contacts are provided, preferably in the form of protruding contact pins.
• filament emulation circuits are connected to the electrical contacts at both ends. These filament emulation circuits serve to provide an electrical behavior between the two contacts at both ends which emulates the filament of a fluorescent tube lamp. Consequently, if the LED replacement lamp including these filament emulation circuits is used in a lighting fixture including a ballast, and in particular an electronic ballast, the electrical behavior will be similar to that of heating filaments; in particular, there will be a defined electrical resistance between the contacts.
• An LED lighting assembly is electrically connected to the filament emulation circuits to be supplied with electrical power.
• the LED lighting assembly comprises said one or more LED lighting elements, and preferably additional circuitry such as a driver circuit to convert the supplied electrical power to current and/or voltage values as required by the LED lighting elements.
• each of the first and second resistor circuits comprises a series connection of at least two resistors, preferably even more such as at least three, or, particularly preferred, at least four resistors.
• a string of resistors as proposed according to the invention has the advantage of increased fault tolerance in case of single component failure. If one of the resistors fails, i. e. is short-circuited, the remaining resistance of the series connection is still sufficient to provide an adequate resistance value between the contacts, or in other words is still above a determined resistance value.
• the filament emulation circuits proposed according to the invention are robust against component failure.
• resistors are arranged in series, the less impact there will be on the overall resistance, in case of a failure of one resistor.
• an arrangement of eight resistors in series will lead to a reduction of the total resistance of the two resistor circuits by only 12.5% in case one of the resistors fails.
• a current limiting circuit connected in series with at least one of the resistor circuits.
• the current circuit element is disposed to prevent an overcurrent from flowing.
• the current limiting circuit cuts off current flow in case of an overcurrent.
• the current limiting circuit may comprise an electrical fuse.
• the filament emulation circuits have an at least substantially symmetrical circuit design with regard to the contacts.
• the resistor circuits preferably have the same combined resistance value.
• the above described current limiting circuit may be provided at only one of the contacts, which is still considered a "substantially symmetrical" circuit design if the resistance value of the (untriggered) current limiting circuit is sufficiently low (e. g. 20 % or less, preferably 10 % or less of the total resistance of the resistor circuits).
• the resistance value of the (untriggered) current limiting circuit is sufficiently low (e. g. 20 % or less, preferably 10 % or less of the total resistance of the resistor circuits).
• At least one of the emulation circuits further comprises a voltage limiting circuit connected in parallel to the resistor circuits.
• a voltage limiting circuit may serve to prevent damage caused by excessive voltage applied between the electrical contacts at one end.
• the voltage limiting circuit may comprise a voltage limiting element, such as a VDR, DIAC, SIDIAC, spark gap, gas discharge tube, or bidirectional thyristor over voltage protector. This allows protecting the lamp circuitry from damage in case mains voltage is directly applied between two contact pins at the same end.
• the resistors of the filament emulation circuits are protected, because the voltage limiting circuit breaks down and shunts the current from the filament resistors.
• the filament emulation resistors are protected from failure.
• Figure 1 shows a symbolic circuit diagram of an embodiment of a lighting arrangement including an LED replacement lamp with filament emulation circuits
• Figure 2 shows a circuit diagram of an embodiment of a filament emulation circuit
• Figures 3a - 3f show examples of lighting arrangements with different wiring of an LED replacement lamp.
• the present invention aims at providing an LED replacement lamp 20 for operation in a lighting arrangement (lighting fixture) intended for a fluorescent tube lamp.
• FIG. 3a shows the wiring of a lamp 10, in this case a fluorescent tube lamp 10, with two electrical contacts at both ends. Electrical mains voltage is supplied at a terminal 12, at which one contact at a first end of the lamp 10 is directly connected, and an input of a ballast 14 is also connected to mains. An output of the ballast 14 is connected to one electrical contact at the other, second end of the lamp 10. Further, the remaining contacts at each end of the lamp 10 are interconnected over a glow starter or electronic starter 16. As known to the skilled person, a fluorescent lamp operated at an electromagnetic ballast as shown is turned on after an initial heating current through the filaments is supplied.
• Fig. 3b shows the wiring for an LED replacement lamp 20, inserted within a lamp fixture instead of a fluorescent tube lamp.
• the starter is replaced by a dummy starter 18. Besides this replacement, no rewiring or modification of the luminaire and ballast are required.
• Fig. 1 shows a symbolic circuit diagram of the LED replacement lamp 20, in this case connected to an electronic ballast 15.
• the lamp 20 is of elongate shape with a first end 22a and opposed second end 22b. At each end 22a, 22b, two electrical contact pins 24a, 26a; 24b, 26b protrude.
• the LED replacement lamp 20 comprises an LED lighting assembly 40, which is not shown in detail.
• the LED lighting assembly 40 comprises an LED driver circuit (not shown) connected to a plurality of LED lighting elements 28 distributed over the length of the LED replacement lamp 20.
• the LED lighting assembly 40 is electrically connected to filament emulation circuits 42 electrically connected to the electrical contacts 24a, 26a; 24b, 26b at both ends 22a, 22b.
• electrical power supplied to the contacts 24a, 26a; 24b, 26b is supplied to the LED lighting assembly 40 such that the LED lighting elements may be operated.
• the electronic ballast 15 supplies a heating current and ignition voltage to start the lamp 20.
• the filament emulation circuits 42 provide a defined electrical resistance between the contact pins 24a, 26a; 24b, 26b at both ends 22a, 22b.
• Fig. 2 shows in greater detail the components of the filament emulation circuit 42 provided at both ends 22a, 22b of the LED replacement lamp 20.
• a PTC element 44 provided as a resettable fuse for overcurrent protection.
• a first resistor circuit 46 Connected in series with the PTC element 44 is a first resistor circuit 46 comprised of a series connection of four resistors.
• the resistors are of equal resistance rating; in a preferred embodiment, the resistors are each SMD components with an electrical resistance of 1 ⁇ .
• a second resistor circuit 48 equally comprised of a series connection of four identical resistors (SMD, 1 ⁇ ).
• the resistor circuits 46, 48 are interconnected at a common terminal 50, where the LED lighting assembly 40 (see Fig. 1) is connected.
• VDR 38 voltage dependent resistor
• the VDR 38 also referred to as varistor, is used as voltage limiting circuit protecting the resistor circuits 46, 48 from overvoltage. If excessive voltage is applied, the VDR 38 breaks down and the current through the VDR 38 will increase significantly, such that the current voltage across the resistors is limited and created by the high voltage is shunted away from the resistor circuits 46, 48.
• the LED replacement lamp 20 equipped with the described filament emulation circuits 42 fulfills a number of important operational and safety functions.
• the resistor circuits 46, 48 emulate a filament resistance of 8 ⁇ , providing a resistive impedance at the contact pins 24a, 26a; 24b, 26b.
• the design of the lamp 20 is symmetrical using identical filament emulation circuits 42 at both ends 22a, 22b.
• the PTC element 44 resettable fuse
• the VDR 38 may, at the low voltages applied during normal operation, be substantially regarded as an open loop
• the design of the filament emulation circuits 42 with regard to the input pins 24a, 26a are also symmetrical. Due to this symmetry, regardless of the wiring order and arrangement of the LED lamp 20 within a fixture, the lamp 20 will always be in the same electrical configuration.
• Some PTCs have substantial ohmic resistance (e. g., several ohms).
• a second PTC may be added in series with the second resistor circuit 48 (i. e. connected between the contact pin 24a and the common node of the VDR 38 and the second resistor circuit 48) to keep the symmetry. Because of the resistance of the PTCs 44, some of the SMD resistors in the first and second resistor circuits 46, 48 may be omitted as long as the total resistance (the series connection of PTCs and resistor circuits 46, 48) is above 8 ⁇ .
• Figs. 3c - 3f show examples of such wiring configurations.
• the lamp 20 is directly connected to mains without a ballast.
• the contact pins at one end are directly connected to mains, leading to a high voltage which will be shunted by the VDR 38, so that the increased current will eventually trigger the PTC 44, while the resistor circuits 46, 48 are protected.
• the lamp 20 may even be re-used in a correct wiring configuration.
• the filament circuits 42 still provide the required safety.
• the design is safe when misused in a wiring configuration with an electromagnetic (EM) ballast.
• Fig. 3a and 3b show such examples.
• the lamp is connected to an EM ballast 14 via a glow starter 16.
• the lamp 20 is connected to an EM ballast 14 via a dummy starter 18. The lamp 20 according to the above described embodiment in both of these misuse cases will not operate.
• the EM ballast 14 is shorted via the filament circuit 42 and the starter, resulting in an increased current through the filament emulation circuits 42.
• the current limiting device (PTC 44) prevents an increased current from overheating the resistor circuits 46, 48 by tripping and interrupting the current in this case.

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• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Optics & Photonics (AREA)
• Circuit Arrangement For Electric Light Sources In General (AREA)

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Publications (1)

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Cited By (3)

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Citations (3)

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• 2014
  • 2014-07-23 WO PCT/EP2014/065772 patent/WO2015014680A1/en not_active Ceased
  • 2014-07-23 DK DK14741900.6T patent/DK3028543T3/en active
  • 2014-07-23 US US14/902,750 patent/US9743466B2/en active Active
  • 2014-07-23 NO NO14741900A patent/NO3028543T3/no unknown
  • 2014-07-23 RU RU2016106634A patent/RU2663816C2/ru active
  • 2014-07-23 EP EP14741900.6A patent/EP3028543B1/en active Active
  • 2014-07-23 PL PL14741900T patent/PL3028543T3/pl unknown
  • 2014-07-23 JP JP2016530436A patent/JP6391690B2/ja active Active
  • 2014-07-23 CN CN201480043274.7A patent/CN105432146B/zh active Active
  • 2014-07-23 ES ES14741900.6T patent/ES2663146T3/es active Active

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