EP0948241A2 - Method and apparatus for supplying power to light emitting diodes - Google Patents
Method and apparatus for supplying power to light emitting diodes Download PDFInfo
- Publication number
- EP0948241A2 EP0948241A2 EP99660053A EP99660053A EP0948241A2 EP 0948241 A2 EP0948241 A2 EP 0948241A2 EP 99660053 A EP99660053 A EP 99660053A EP 99660053 A EP99660053 A EP 99660053A EP 0948241 A2 EP0948241 A2 EP 0948241A2
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- EP
- European Patent Office
- Prior art keywords
- current
- light emitting
- main circuit
- circuit
- switching element
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 238000000034 method Methods 0.000 title claims abstract description 25
- 239000011159 matrix material Substances 0.000 claims abstract description 22
- 238000012544 monitoring process Methods 0.000 claims description 16
- 238000004804 winding Methods 0.000 claims description 16
- 230000001939 inductive effect Effects 0.000 description 14
- 230000007423 decrease Effects 0.000 description 5
- 239000003990 capacitor Substances 0.000 description 3
- WLJWJOQWLPAHIE-YLXLXVFQSA-N (2s)-2-[[(2s)-2-[[(2s)-2-[[(2s,3s)-2-amino-3-methylpentanoyl]amino]propanoyl]amino]-3-methylbutanoyl]amino]pentanedioic acid Chemical compound CC[C@H](C)[C@H](N)C(=O)N[C@@H](C)C(=O)N[C@@H](C(C)C)C(=O)N[C@H](C(O)=O)CCC(O)=O WLJWJOQWLPAHIE-YLXLXVFQSA-N 0.000 description 2
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
Images
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]
- H05B45/30—Driver circuits
- H05B45/37—Converter circuits
- H05B45/3725—Switched mode power supply [SMPS]
- H05B45/382—Switched mode power supply [SMPS] with galvanic isolation between input and output
Definitions
- the invention relates to a method for supplying power to light emitting diodes connected to a light emitting diode matrix comprising one or more parallel connected individual light emitting diodes or a series connection thereof.
- Light eniitting diodes are generally used in lighting fixtures, such as outdoor signs, commercial signs and the like. Connecting devices provided with a series resistor are conventionally used for operating light emitting diodes, whereby the arrangement causes unnecessary power loss. Particularly in battery-driven systems the series resistor significantly reduces the operating life as the battery capacity is limited. An example of such a battery-driven lighting system is the emergency exit lighting fixture, which should operate also when the mains voltage dies out.
- Another conventional drawback with light emitting diodes using a series resistor is the dependence on a particular voltage level.
- the function of a series resistor is to arrange each voltage level to suit the use of light emitting diodes, in which case the fluctuation in voltage level causes problems for the light emitting diodes regarding their durability. An incorrect voltage level may provide such a high current that despite a bias resistor the light emitting diode may be broken. A too low supply voltage, in turn, is not adequate for a light emitting diode.
- the voltage level has a commanding effect in conventional solutions provided with a series resistor.
- the object is achieved with a method of the invention, characterized by comprising the steps of
- the method of the invention is based on the idea that an inductive component is connected in series with the light emitting diodes.
- the current of the light emitting diodes is monitored, and when the current exceeds a particular suitable predetermined limit the main circuit is opened, whereby the increase of light emitting diode current stops and the current starts flowing in a current loop forced by the inductive component. Then, as the energy stored in the inductive component decreases, the current of the light emitting diodes also decreases. When the current is reduced to a predetermined value, the main circuit can be closed again.
- the power supply method of the light emitting diodes of the invention has extremely low losses, since the use thereof does not require a series resistor for the light emitting diodes. During the use, the method can also be applied to varying voltage levels, and the method is therefore applicable to be used in demanding conditions and environments.
- the invention also relates to a power supply apparatus of light emitting diodes comprising a light emitting diode matrix formed of one or more parallel connected individual light emitting diodes or a series connection thereof, characterized in that the power supply apparatus also comprises an inductance and a switching element, whereby a series connection of the light emitting diode matrix, the inductance and the switching element forms a main circuit of the power supply apparatus connected to a working voltage, a current monitoring block of the main circuit also arranged to control the switching element, a second current monitoring block arranged to convey a control signal to the block arranged to control the switching element, and a zero diode connected in parallel with the series connection of the inductance and the light emitting diode matrix in anti-parallel relation to the light emitting diodes of the light emitting diode matrix.
- Figure 1 shows a circuit implementing the method of the invention comprising a light emitting diode matrix MN including N light emitting diodes connected in series and M parallel connections thereof.
- One end of the light emitting diode matrix is connected to a positive supply voltage U in and the other end is connected to an inductive component N1.
- the inductive component N1 is a primary winding of a transformer T1.
- One electrode of the inductive component is further connected to a controllable switching element K1.
- This series circuit formed of the light emitting diode matrix MN, the inductive component N1 and the switching element K1 forms a main circuit of the power supply apparatus of the invention, to which the supply voltage U in is connected.
- the main circuit also comprises a series resistor R2.
- Figure 1 also shows a zero diode D1 of the circuit connected in the opposite direction in parallel with the series connection of the inductive component and the light emitting diode matrix.
- FIG. 1 also shows capacitors C1 and C2, the function of which is to operate as elements filtering and storing energy.
- the capacitor C2 in particular stores and filters the working voltage V c of the auxiliary circuits needed in the apparatus.
- a resistance R1 of the circuit functions as a loading resistor, through which the working voltage needed by the auxiliary circuits is at first fed.
- the current i L x decreases linearly, whereby the amount of current in the zero diode circuit is monitored in accordance with the invention and the main circuit is closed using the switching element K1 when said current has reached a predetermined limit.
- the predetermined limit can be defined, for example, so as to control the switch K1 when the current of the zero diode circuit dies out completely.
- the current may increase again in the main circuit, and said method phases are repeated in order to constantly operate the light emitting diodes.
- the current of the light emitting diode matrix forms the saw-tooth wave, shown in Figure 2, whose rising edge is the current i L and falling edge is the i L x .
- the current of the light emitting diodes thus stays constant despite the variations in the working voltage.
- the amount of working voltage affects only the operating frequency of the switch K1, since the current i L increases more rapidly into its peak value as the voltage U in increases, but then again the amount of working voltage does not affect the amount or fall time of the current i L x .
- the light power produced by the light emitting diode matrix remains substantially constant irrespective of the level of the supply voltage.
- This is particularly important when the apparatus implementing the method is battery-driven, because as the capacity of the battery decreases its terminal voltage declines.
- a battery-driven apparatus may be, for example, an emergency exit lighting fixture, which is normally supplied by an electrical network, in which case the supply voltage of the apparatus can vary significantly.
- a notable advantage of the method of the invention is the independence of the available light power of the supply voltage level variations.
- the current of the main circuit is monitored from the voltage that is over a series resistor R2 connected to the current circuit.
- Figure 1 shows how a current monitoring block A measures the voltage that is over the resistor R2.
- the current of the main circuit reaches its peak value, then the voltage that is over the resistance R2 reaches the limit that is proportioned to the peak value of the current, and block A controls the switch K1 to open the main circuit.
- Current information about the zero diode circuit needed to close the main circuit is obtained in accordance with the preferred embodiment presented in Figure 1 through a secondary winding N2 of a transformer T1, when a primary winding N1 of the transformer is an inductive component connected to the main circuit.
- the winding N2 is connected to a current defining element C informing an element A arranged to control the switch K1 about the amount of current in the zero diode circuit in order to control the switch to a conducting state.
- the switch K2 can bypass the zero diode D1, in which case the zero diode circuit and at the same time the entire dissipation power of the switch can be minimized.
- the current starts flowing in the zero diode circuit, whereafter the switching element K2 arranged in parallel with the zero diode D1 is switched to a conducting state.
- the amount of current is monitored as the current flows in the zero diode circuit, and as the current reaches a particular predetermined limit the switch K2 is switched from the conducting state.
- the apparatus implementing the method comprises as an inductive component N1 a transformer T1 whose secondary winding N3 provides current informa-tion for block B controlling the switch K2, on the basis of which the switch K2 is controlled.
- Block B changes the current information obtained from the winding to timing information, for example, using internal logic or trigger circuits.
- the circuit according to Figure 1 also comprises a diode D2 connected to the secondary winding N2 of the transformer T1.
- the diode aims to supply current through the winding N2 of the transformer to the capacitor C2 maintaining the working voltage V c of the auxiliary circuits of the circuit. Power is thus saved, as the supply voltage U in does not need to be used directly through a resistor R1 in order to form the working voltage.
Landscapes
- Circuit Arrangement For Electric Light Sources In General (AREA)
- Led Devices (AREA)
Abstract
The invention relates to a method and an apparatus for supplying power to
light emitting diodes connected to a light emitting diode matrix (MN) comprising
one or more parallel connected light emitting diodes or a series connection
thereof. The method comprises repeated phases where the amount of current
in the main circuit formed of a series connection of the light emitting diode
matrix (MN), a switching element (K1) and an inductance (N1) is monitored,
the main circuit is opened by the switching element (K1) when the current of
the main circuit reaches a predetermined value, whereby the current starts
flowing through a zero diode circuit formed of a zero diode (D1) arranged on a
circuit, the amount of current in the zero diode circuit is monitored, and the
main circuit is closed by the switching element (K1) when the zero diode circuit
current reaches a predetermined value.
Description
The invention relates to a method for supplying power to light emitting
diodes connected to a light emitting diode matrix comprising one or more
parallel connected individual light emitting diodes or a series connection
thereof.
Light eniitting diodes are generally used in lighting fixtures, such as
outdoor signs, commercial signs and the like. Connecting devices provided
with a series resistor are conventionally used for operating light emitting diodes,
whereby the arrangement causes unnecessary power loss. Particularly
in battery-driven systems the series resistor significantly reduces the operating
life as the battery capacity is limited. An example of such a battery-driven
lighting system is the emergency exit lighting fixture, which should operate
also when the mains voltage dies out.
Another conventional drawback with light emitting diodes using a
series resistor is the dependence on a particular voltage level. The function of
a series resistor is to arrange each voltage level to suit the use of light emitting
diodes, in which case the fluctuation in voltage level causes problems for the
light emitting diodes regarding their durability. An incorrect voltage level may
provide such a high current that despite a bias resistor the light emitting diode
may be broken. A too low supply voltage, in turn, is not adequate for a light
emitting diode. As for the function of the light emitting diode, the voltage level
has a commanding effect in conventional solutions provided with a series resistor.
It is an object of the present invention to provide a method that
avoids the above drawbacks and enables a more reliable power supply to light
emitting diodes with a smaller power loss. The object is achieved with a
method of the invention, characterized by comprising the steps of
The method of the invention is based on the idea that an inductive
component is connected in series with the light emitting diodes. The current of
the light emitting diodes is monitored, and when the current exceeds a particular
suitable predetermined limit the main circuit is opened, whereby the increase
of light emitting diode current stops and the current starts flowing in a
current loop forced by the inductive component. Then, as the energy stored in
the inductive component decreases, the current of the light emitting diodes
also decreases. When the current is reduced to a predetermined value, the
main circuit can be closed again. The power supply method of the light emitting
diodes of the invention has extremely low losses, since the use thereof
does not require a series resistor for the light emitting diodes. During the use,
the method can also be applied to varying voltage levels, and the method is
therefore applicable to be used in demanding conditions and environments.
The invention also relates to a power supply apparatus of light
emitting diodes comprising a light emitting diode matrix formed of one or more
parallel connected individual light emitting diodes or a series connection
thereof, characterized in that the power supply apparatus also comprises an
inductance and a switching element, whereby a series connection of the light
emitting diode matrix, the inductance and the switching element forms a main
circuit of the power supply apparatus connected to a working voltage, a current
monitoring block of the main circuit also arranged to control the switching
element, a second current monitoring block arranged to convey a control signal
to the block arranged to control the switching element, and a zero diode
connected in parallel with the series connection of the inductance and the light
emitting diode matrix in anti-parallel relation to the light emitting diodes of the
light emitting diode matrix. By means of such an apparatus the advantages
offered by a power supply method can be achieved with a simple, but reliable,
structure.
In the following the invention will be described in greater detail in
connection with the preferred embodiments and with reference to the accompanying
drawings, in which
Figure 1 shows a circuit implementing the method of the invention
comprising a light emitting diode matrix MN including N light emitting diodes
connected in series and M parallel connections thereof. One end of the light
emitting diode matrix is connected to a positive supply voltage Uin and the
other end is connected to an inductive component N1. According to an embodiment
of the invention the inductive component N1 is a primary winding of
a transformer T1. One electrode of the inductive component is further connected
to a controllable switching element K1. This series circuit formed of the
light emitting diode matrix MN, the inductive component N1 and the switching
element K1 forms a main circuit of the power supply apparatus of the invention,
to which the supply voltage Uin is connected. In the preferred embodiment
of the invention, shown in Figure 1, the main circuit also comprises a series
resistor R2. Figure 1 also shows a zero diode D1 of the circuit connected in
the opposite direction in parallel with the series connection of the inductive
component and the light emitting diode matrix.
Figure 1 also shows capacitors C1 and C2, the function of which is
to operate as elements filtering and storing energy. The capacitor C2 in particular
stores and filters the working voltage Vc of the auxiliary circuits needed
in the apparatus. A resistance R1 of the circuit functions as a loading resistor,
through which the working voltage needed by the auxiliary circuits is at first
fed.
When the main circuit is connected to the supply voltage and when
the switching element K1 is in a conducting state the current iL flowing through
the light emitting diode matrix starts increasing according to the equation
i L = Uin -NVL / L t1
, where Uin is the amount of supply voltage, N is the number
of light emitting diodes connected in series, VL is the forward voltage of one
light emitting diode, L is the inductance of the inductive component of the main
circuit and t1 is the time that the switch K1 is closed. The current described by
the equation increases linearly with time as shown in Figure 2. In accordance
with the method of the invention the amount of current iL is monitored, and the
switching element K1 opens the main circuit when the current reaches a predetermined
value, which is the peak value of the current ÎL.
When the main circuit is opened, the current therein starts flowing in
the zero diode circuit formed of the zero diode D1, the light emitting diode matrix
MN and the inductive component N1. The energy stored in the inductive
component enables the current flow in said circuit. The current of the zero diode
circuit employs the following equation
i L x = NVL - VD / L (t2 - t1), where N is
the number of light emitting diodes connected in series, VL is the forward voltage
of one light emitting diode, L is the inductance of the inductive component
of the main circuit, t1 is the time that the switch K1 is closed, t2 is the time when
the switch K1 will be closed and VD is the forward voltage of the diode D1.
Then the difference between the times t2 and t1 forms the time that the switch
K1 is not conducting. The current iL x decreases linearly, whereby the amount
of current in the zero diode circuit is monitored in accordance with the invention
and the main circuit is closed using the switching element K1 when said
current has reached a predetermined limit. The predetermined limit can be
defined, for example, so as to control the switch K1 when the current of the
zero diode circuit dies out completely. The current may increase again in the
main circuit, and said method phases are repeated in order to constantly operate
the light emitting diodes.
The current of the light emitting diode matrix forms the saw-tooth
wave, shown in Figure 2, whose rising edge is the current iL and falling edge is
the iL x. The average value of the current, or the average current IAVE,can thus
be geometrically interpreted as IAVE = ½ÎL, i.e. the average current amount is
half of the peak value of the current. The current of the light emitting diodes
thus stays constant despite the variations in the working voltage. The amount
of working voltage affects only the operating frequency of the switch K1, since
the current iL increases more rapidly into its peak value as the voltage Uin increases,
but then again the amount of working voltage does not affect the
amount or fall time of the current iL x. Hence, the light power produced by the
light emitting diode matrix remains substantially constant irrespective of the
level of the supply voltage. This is particularly important when the apparatus
implementing the method is battery-driven, because as the capacity of the
battery decreases its terminal voltage declines. Such a battery-driven apparatus
may be, for example, an emergency exit lighting fixture, which is normally
supplied by an electrical network, in which case the supply voltage of the apparatus
can vary significantly. A notable advantage of the method of the invention
is the independence of the available light power of the supply voltage
level variations.
According to a preferred embodiment of the invention the current of
the main circuit is monitored from the voltage that is over a series resistor R2
connected to the current circuit. Figure 1 shows how a current monitoring
block A measures the voltage that is over the resistor R2. When the current of
the main circuit reaches its peak value, then the voltage that is over the resistance
R2 reaches the limit that is proportioned to the peak value of the current,
and block A controls the switch K1 to open the main circuit. Current information
about the zero diode circuit needed to close the main circuit is obtained in
accordance with the preferred embodiment presented in Figure 1 through a
secondary winding N2 of a transformer T1, when a primary winding N1 of the
transformer is an inductive component connected to the main circuit. The
winding N2 is connected to a current defining element C informing an element
A arranged to control the switch K1 about the amount of current in the zero
diode circuit in order to control the switch to a conducting state.
According to a preferred embodiment of the present invention the
switch K2 can bypass the zero diode D1, in which case the zero diode circuit
and at the same time the entire dissipation power of the switch can be minimized.
In accordance with the embodiment it is observed that the current
starts flowing in the zero diode circuit, whereafter the switching element K2
arranged in parallel with the zero diode D1 is switched to a conducting state.
The amount of current is monitored as the current flows in the zero diode circuit,
and as the current reaches a particular predetermined limit the switch K2
is switched from the conducting state. For this purpose, the apparatus implementing
the method, shown in Figure 1, comprises as an inductive component
N1 a transformer T1 whose secondary winding N3 provides current informa-tion
for block B controlling the switch K2, on the basis of which the switch K2 is
controlled. Block B changes the current information obtained from the winding
to timing information, for example, using internal logic or trigger circuits. A
great advantage provided by the power supply apparatus implementing the
method of the invention is the low losses of the circuit which can further be
reduced by utilizing the switch K2 bypassing the zero diode D1. As the dissipation
power decreases in battery-driven apparatuses the operating time of
the power supply apparatus correspondingly increases.
The circuit according to Figure 1 also comprises a diode D2 connected
to the secondary winding N2 of the transformer T1. When the apparatus
is operating the diode aims to supply current through the winding N2 of the
transformer to the capacitor C2 maintaining the working voltage Vc of the auxiliary
circuits of the circuit. Power is thus saved, as the supply voltage Uin does
not need to be used directly through a resistor R1 in order to form the working
voltage.
It is obvious for those skilled in the art that the basic idea of the invention
can be implemented in various ways. The invention and its embodiments
are thus not restricted to the above examples but can be modified
within the scope of the attached claims.
Claims (10)
- A method for supplying power to light emitting diodes connected to a light emitting diode matrix (MN) comprising one or more parallel connected individual light emitting diodes or a series connection thereof, characterized by comprising the steps ofmonitoring the amount of current in a main circuit formed of the series connection of the light emitting diode matrix (MN), a switching element (K1) and an inductance (N1),opening the main circuit by a switching element (K1) when the main circuit current reaches a predetermined value, whereby the current starts flowing through a zero diode circuit formed of a zero diode (D1) arranged on a circuit,monitoring the amount of current in the zero diode circuit, and closing the main circuit by the switching element (K1) when the current of the zero diode circuit reaches a predetermined value.
- A method as claimed in claim 1, characterized by comprising the steps ofdetecting the movement of the current to the zero diode circuit,switching the switch (K1) arranged in parallel with the zero diode (D1) to a conducting state,monitoring the amount of current in the zero diode circuit, andswitching the switch (K2) arranged in parallel with the zero diode (D1) from the conducting state when the current of the zero diode circuit reaches a predetermined value.
- A method as claimed in claim 2, characterized in that monitoring the current of the zero diode circuit comprises the step of
monitoring the current of the zero diode circuit by using a winding (N3) of a transformer (T1) connected to the main circuit, the primary winding of the transformer (T1) being an inductance (N1) arranged to the main circuit. - A method as claimed in claims 1, 2 or 3, characterized in that monitoring the current of the main circuit comprises the step of
monitoring the voltage over a resistor (R2) connected to the main circuit. - A method as claimed in any one of the preceding claims 1 - 4, characterized in that monitoring the current of the main circuit comprises the step of
monitoring the current of the zero diode circuit by using a winding (N2) of the transformer (T1) connected to the main circuit, the primary winding of the transformer (T1) being the inductance (N1) arranged to the main circuit. - A power supply apparatus of light emitting diodes comprising a light emitting diode matrix (MN) formed of one or more parallel connected individual light emitting diodes or a series connection thereof, characterized in that the power supply apparatus also comprises an inductance (N1) and a switching element (K1), whereby a series connection of the light emitting diode matrix (MN), the inductance (N1) and the switching element (K1) forms a main circuit of the power supply apparatus connected to a working voltage (Uin), a current monitoring block (A) of the main circuit also arranged to control the switching element (K1), a second current monitoring block (C) arranged to convey a control signal to the block (A) arranged to control the switching element (K1), and a zero diode (D1) connected in parallel with the series connection of the inductance (N1) and the light emitting diode matrix in anti-parallel relation to the light emitting diodes of the light emitting diode matrix.
- A power supply apparatus as claimed in claim 6, characterized by further comprising a switching element (K2) and a control block (B) connected thereto arranged to control the switching element (K2) arranged in parallel with the zero diode (D1 ).
- A power supply apparatus as claimed in claim 6 or 7, characterized by also comprising a transformer (T1) whereby the inductance (N1) connected to the main circuit is the primary winding of the transformer (T1) and the current defining block (C) is connected to a secondary winding (N2) of the transformer.
- A power supply apparatus as claimed in claim 6, 7 and 8, characterized in that the inductance (N1) connected to the main circuit is the primary winding of the transformer (T1) and a control block (B) is con-nected to a secondary winding (N3) of the transformer.
- A power supply apparatus as claimed in any one of the preceding claims 6 - 9, characterized in that the main circuit of the power supply apparatus also comprises a series resistor (R2).
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI980717 | 1998-03-30 | ||
| FI980717A FI104034B (en) | 1998-03-30 | 1998-03-30 | Method and device for supplying power to light emitting diodes |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0948241A2 true EP0948241A2 (en) | 1999-10-06 |
| EP0948241A3 EP0948241A3 (en) | 2000-12-27 |
Family
ID=8551412
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP99660053A Withdrawn EP0948241A3 (en) | 1998-03-30 | 1999-03-25 | Method and apparatus for supplying power to light emitting diodes |
Country Status (2)
| Country | Link |
|---|---|
| EP (1) | EP0948241A3 (en) |
| FI (1) | FI104034B (en) |
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004006629A3 (en) * | 2002-07-04 | 2004-03-25 | Tridonic Optoelectronics Gmbh | Power supply unit for light-emitting diodes |
| EP1033903A3 (en) * | 1999-01-22 | 2004-05-06 | Nokia Corporation | Illuminating electronic device and illumination method |
| WO2004057921A1 (en) * | 2002-12-19 | 2004-07-08 | Koninklijke Philips Electronics N.V. | Supply assembly for a led lighting module |
| WO2007121798A1 (en) * | 2006-04-21 | 2007-11-01 | Tridonicatco Gmbh & Co. Kg | Led driver circuit |
| DE102008039351B3 (en) * | 2008-08-22 | 2010-01-28 | Osram Gesellschaft mit beschränkter Haftung | Circuit arrangement for operating at least one semiconductor light source |
| WO2010046065A1 (en) * | 2008-10-20 | 2010-04-29 | Tridonicatco Schweiz Ag | Operating circuit for leds |
| WO2010045666A1 (en) | 2008-10-20 | 2010-04-29 | Tridonicatco Gmbh & Co Kg | Operating connection for light emitting diodes |
| US7708447B2 (en) | 2002-07-04 | 2010-05-04 | Tridonic Optoelectronics Gmbh | Current supply for luminescent diodes |
| WO2010049074A1 (en) * | 2008-10-20 | 2010-05-06 | Tridonicatco Schweiz Ag | Operating circuit for light-emitting diodes |
| WO2010124313A2 (en) | 2009-04-30 | 2010-11-04 | Tridonic Gmbh & Co Kg | Operating circuit for light-emitting diodes |
| DE102009042419A1 (en) * | 2009-09-21 | 2011-03-31 | Osram Gesellschaft mit beschränkter Haftung | Circuit arrangement for operating at least one LED |
| WO2011113958A1 (en) * | 2010-03-19 | 2011-09-22 | Tridonic Ag | Low-voltage power supply for an led lighting system |
| DE102013207562A1 (en) * | 2013-04-25 | 2014-10-30 | Tridonic Gmbh & Co Kg | Operating circuit for LEDs with voltage measurement |
| DE10262387B3 (en) * | 2002-07-04 | 2016-01-21 | Tridonic Ag | Power supply for light-emitting diodes |
| DE102006034371B4 (en) | 2006-04-21 | 2019-01-31 | Tridonic Ag | Operating circuit and operating method for light-emitting diodes |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5072171A (en) * | 1990-01-23 | 1991-12-10 | Hughes Aircraft Company | High efficiency power converter employing a synchronized switching system |
| DE4022498A1 (en) * | 1990-07-14 | 1992-01-16 | Stahl R Schaltgeraete Gmbh | Explosion protected warning light - has light element in series circuit, contg. inductance, electronic switch and current |
| FR2751805B1 (en) * | 1996-07-24 | 1998-09-11 | Schneider Electric Sa | SELF-OSCILLATING FULL DEMAGNETIZATION LOWER CONVERTER |
-
1998
- 1998-03-30 FI FI980717A patent/FI104034B/en not_active IP Right Cessation
-
1999
- 1999-03-25 EP EP99660053A patent/EP0948241A3/en not_active Withdrawn
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| EP1033903A3 (en) * | 1999-01-22 | 2004-05-06 | Nokia Corporation | Illuminating electronic device and illumination method |
| US7071762B2 (en) | 2001-01-31 | 2006-07-04 | Koninklijke Philips Electronics N.V. | Supply assembly for a led lighting module |
| EP2001269A1 (en) * | 2002-07-04 | 2008-12-10 | Ledon Lighting Jennersdorf GmbH | Electricity supply for luminescence diodes |
| US8207689B2 (en) | 2002-07-04 | 2012-06-26 | Tridonic Ag | Current supply for luminescent diodes |
| US8063575B2 (en) | 2002-07-04 | 2011-11-22 | Tridonic Jennersdorf Gmbh | Current supply for luminescent diodes |
| DE10230103B4 (en) * | 2002-07-04 | 2012-10-31 | Tridonic Ag | Power supply for light-emitting diodes |
| WO2004006629A3 (en) * | 2002-07-04 | 2004-03-25 | Tridonic Optoelectronics Gmbh | Power supply unit for light-emitting diodes |
| EP2262347A1 (en) * | 2002-07-04 | 2010-12-15 | Ledon Lighting Jennersdorf GmbH | Power supply for light emitting diodes |
| DE10262387B3 (en) * | 2002-07-04 | 2016-01-21 | Tridonic Ag | Power supply for light-emitting diodes |
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Also Published As
| Publication number | Publication date |
|---|---|
| FI980717A7 (en) | 1999-10-01 |
| FI980717A0 (en) | 1998-03-30 |
| EP0948241A3 (en) | 2000-12-27 |
| FI104034B1 (en) | 1999-10-29 |
| FI104034B (en) | 1999-10-29 |
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