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
  • H05B47/00—Circuit arrangements for operating light sources in general, i.e. where the type of light source is not relevant
  • H05B47/10—Controlling the light source
• • 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]
  • H05B45/10—Controlling the intensity of the light
  • H05B45/12—Controlling the intensity of the light using optical feedback
• • 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]
  • H05B45/10—Controlling the intensity of the light
  • H05B45/18—Controlling the intensity of the light using temperature feedback

Definitions

• the invention relates to the field of driving a light-emitting diode module.
• LEDs Light-emitting diodes
• LEDs have the advantage of a long service life, which is why they are used for different areas. For example, they are often used for
• Emergency lights are used, which are automatically switched on when a power supply to other bulbs such as gas discharge lamps fails.
• LEDs Depending on the type of use of the LEDs, high demands are placed on the constant operation of light-emitting diodes. For example, LEDs must deliver a predetermined light output.
• a known problem with light-emitting diodes is the procurement of replacement for failed LED modules, as the LED development progresses very quickly and thus is no longer assured after a few months that a certain LED with a certain performance is still available on the market.
• the invention therefore has for its object to provide a LED module and a method for controlling a light-emitting diode module, by which the characteristic of a light-emitting diode array are emulated can, and in particular by which the luminous efficacy of the light-emitting diode array can be regulated to a solicitstiinmten value.
• the present invention relates to a light-emitting diode module comprising a light emitting diode array, a load connected in parallel with the LED array, a first transducer connected to the light emitting diode array, and a second transducer connected to the load for dividing the a current or voltage source supplied electrical characteristic to the light emitting diode array and the load, and a control unit for driving the first and second converter such that the operation of the light emitting diode array corresponds to a predetermined setting.
• the predetermined mode of operation corresponds to a predetermined light output of the LED array.
• the load consumes the electrical characteristic supplied to the load by means of the second transducer.
• the load can be heated by the electrical characteristic.
• the load can be an ohmic resistance.
• the module further comprises a measuring unit for determining the electrical characteristic supplied by the current or voltage source and transmitting the data to the control unit.
• the module further comprises a light sensor for determining the light output of the light-emitting diode arrangement.
• the light sensor can transmit the determined data to the control unit.
• the module further comprises a temperature sensor for determining the temperature of the light-emitting diode arrangement.
• the temperature sensor can transmit the determined data to the control unit.
• control unit can change the control of the first and / or second converter on the basis of the transmitted data.
• the present invention relates to a method for controlling a light-emitting diode module, comprising the steps of providing a light-emitting diode arrangement, providing a load connected in parallel with the light-emitting diode arrangement, dividing the electrical characteristic value supplied by a current or voltage source onto the light-emitting diodes Arrangement and the load by means of a to the first transducer connected to the light-emitting diode array and a second transducer connected to the load, and to drive the first and second transducers such that the operation of the light-emitting diode array corresponds to a predetermined setting.
• Fig. 2 shows schematically a block diagram according to the light-emitting diode module according to the present invention
• Fig. 3 shows schematically the steps of the method according to the present invention.
• Fig. 1 shows two examples of a typical characteristic curve of a light-emitting diode array.
• a light-emitting diode arrangement in the sense of the present invention may in this case comprise a single light-emitting diode or a plurality of light-emitting diodes connected in series and / or in parallel.
• the curves Ki and K 2 are hereby plotted as curves within a coordinate system in which the forward voltage U, ie the voltage with which the light-emitting diode arrangement is operated, is shown on the x-axis and in which the y-axis of FIG Forward current I is shown, that is, the current which through the Light-emitting diode arrangement flows.
• the characteristic curve of a light-emitting diode looks such that a current flow only begins at a defined flow voltage. Ideally, the resistance of the light emitting diode in the range greater than the forward voltage would be zero and the current would rise steeply. In practice, the characteristic increases in the range above the flow voltage with a substantially constant slope.
• a light-emitting diode may have a different forward current for the same applied voltage, so that with the same applied forward voltage, light-emitting diodes with different characteristic curves also each have a different forward current and therefore also deliver a different light output in particular.
• LEDs with an improved characteristic have the same forward voltage to a higher light output.
• FIG. 1 schematically shows two characteristic curves Ki and K 2 of two different light-emitting diode arrangements or light-emitting diodes.
• the characteristic K 2 corresponds to an improved light-emitting diode arrangement, since a higher forward current is achieved at the same forward voltage. Nevertheless, an increased forward current and thus an increased light output as explained above partially undesirable. Accordingly, for different light-emitting diode arrangements also different forward voltages arise at the same forward flow. On the other hand, it is partial not feasible to adjust the supply voltage or the supply current for a light-emitting diode array accordingly.
• the present invention therefore proposes, by a corresponding circuit within the LED module, the electrical characteristic, i. E. to divide the supply voltage or theestablishedsström, on the light-emitting diode arrangement and on another consumer.
• the electrical characteristic i. E. to divide the supply voltage or theestablishedsström
• the forward current is reduced by reducing the forward voltage on the light-emitting diode arrangement as with another light-emitting diode arrangement, or it can be achieved that the forward voltage is reduced by the same forward voltage as in the case of another light-emitting diode arrangement.
• Arrangement is present.
• the characteristic K 1 here is the characteristic of a light-emitting diode, which was provided for example in the delivery in a light-emitting diode module. With a forward voltage Ui, a forward current Ii could be generated at the light-emitting diode arrangement. If this originally built into the LED module LED fails and is replaced by a new light emitting diode, which has an improved characteristic, referred to as K 2 in Fig. 1, this new LED would have an increased forward current at the same forward voltage Ui.
• the present invention therefore proposes to regulate the forward voltage to the new light emitting diode array to the effect that the new LED array is operated with a forward voltage U 2 , which is smaller than the originally provided on the light emitting diode array forward voltage Ui, so that by the new light-emitting diode arrangement of same forward current Ii flows as through the replaced light emitting diode array.
• FIG. 2 shows schematically a block diagram of an LED module 1 according to the present invention.
• an electrical characteristic i. a supply voltage or supply current to, for example, supplied by the power network.
• the supply voltage is constant, and can only be varied by additional components and complex measures.
• the light-emitting diode module 1 comprises a light-emitting diode arrangement 6 and a load 7 connected in parallel with the light-emitting diode arrangement 6.
• the load 7 connected in parallel is in this case not connected directly to the light-emitting diode module 1.
• a first transducer 4 is connected to the light emitting diode array 6 and a second transducer 5 is connected to the load.
• the first converter 4 and the second converter 5 are either direct or via other components connected to the supply voltage or the supply current.
• the two transducers 4, 5 can be controlled independently of each other.
• the first converter 4 and the second converter 5 are designed to transmit only a certain part of the supply voltage or of the supply current to the respectively connected components. That is, the first converter 4 may transmit a lower voltage than the supply voltage to the light emitting diode array 6, and the second converter 5 may transmit a lower voltage than the supply voltage to the load 7.
• the transducers 4, 5 may each deliver a lower current than the supply flow to the respective components.
• the light-emitting diode module 1 further comprises a control unit 3, which may in particular also include a microcontroller, for controlling the components of the light-emitting diode module 1.
• the control unit 3 is adapted to drive the first transducer 4 and the second transducer 5 and so To determine which part of the supply voltage or the supply current to the light emitting diode array 6 and the load 7 to be transmitted.
• a forward voltage to the LED array 6 can be adjusted so that a predetermined forward current flows through the light emitting diode array 6 and it can be set the forward current to the LED array 1 so that a predetermined forward voltage to the light emitting diode array 6 is present.
• a predetermined mode of operation or Operation of the light-emitting diode array 6 ensured so that in particular the light output of the newly installed LED array 6 corresponds to the light output of the old replaced light-emitting diode arrangement.
• the present invention it is therefore possible to emulate the characteristic of the old light emitting diode. That is, the light output of the new light-emitting diode array 6 is in the sense of an electrical characteristic as well as that of the LED array to be emulated, which has been replaced.
• the present invention thus provides an active control of the transducers 4, 5, so that the electrical characteristic transmitted to the load 7 can be determined as a function of the predefined characteristic curves.
• a measuring unit 2 can be provided in the light-emitting diode module 1, which measures the electrical characteristic applied to the terminals A and B, i. the supply voltage or thegrownsström, determined and transmitted this data to the control unit 3. This ensures that the light emitting diode module 1 can be connected to different supply voltages or supply currents, since depending on the applied electrical characteristic, the control unit 3, the first converter 4 and the second converter 5 so that always the same desired electrical characteristic at the Light-emitting diode arrangement 6 is present.
• the load 7 is provided here as a pure consumer.
• the load 7 consumes the supplied to the load 7 electrical characteristic by this example in invisible energy converts.
• the load 7 is an ohmic resistor, which heats up by applying the corresponding voltage or the corresponding current and thus converts the electrical characteristic into heat.
• a light sensor 8 can be provided which measures the luminous efficacy of the light-emitting diode arrangement 6 and transmits the determined data to the control unit 3. This can then be used by the control unit 3 for fine correction of possible fluctuations, so that the desired light output can be adjusted by correcting a forward voltage or a forward current at the light-emitting diode arrangement 6.
• the luminosity of the LED array 6 may decrease with increasing time, so that a correction of the forward voltage or the forward current is necessary.
• a temperature sensor 9 may be provided which measures the temperature within the light-emitting diode module 1 and also transmits this data to the control unit 3. This is particularly advantageous if the load 7 is an ohmic resistance which heats up. If the light-emitting diode module 1 heats up too much, the control unit 3 may if necessary control the first converter 4 and the second converter 5 for a short time in such a way that the electrical parameter supplied to the load 7 is reduced, so that a cooling of the Light-emitting diode module 1 is possible. Another possibility is to provide a communication input (not shown in the figure) on the light-emitting diode module 1, by means of which, for example, an external computer can be used to intervene in the system from outside.
• Fig. 3 shows schematically the steps according to an exemplary method of the present invention.
• the process begins in step SO, for example, with the completion of a light-emitting diode module 1.
• step Sl which can already be done on the manufacturer side, the characteristic of the old LED array, i. the originally provided in the light-emitting diode module 1 arrangement detected.
• step S2 the characteristic of the new light-emitting diode arrangement 6 is also detected in the case of replacement of the old LED array. This can either be done in a separate measurement or the corresponding data can be delivered together with the new light emitting diode and then loaded onto the control unit 3.
• the control unit 3 can then determine the forward voltage to be transmitted to the light-emitting diode arrangement 6 or the forward current to be transmitted.
• control unit 3 sends corresponding signals to the first converter 4 and to the second transducer 5, so that the desired forward voltage or the desired forward current is applied to the light-emitting diode arrangement 6 and the difference between the electrical characteristic supplied by the terminals A and B and the voltage applied to the LED array 6 electrical characteristic via the second converter 5 is delivered to the load 7.
• the sensor data can be detected, i. the
• step S6 may be to others
• Time points, for example, after the step Sl can be performed on the old module.
• step S7 the control unit 3 checks whether the light-emitting diode module 1 has the desired operating mode. This includes, in particular, whether the desired light output is achieved and whether, if necessary, overheating takes place. If the control unit has determined in step S7 that the light-emitting diode module has the desired mode of operation, normal operation ensues in step S8 until the process ends in step S10, for example when the light-emitting diode module 1 is switched off.
• control unit 3 determines in step S7 that the light-emitting diode module does not have the desired mode of operation, determines a new electrical characteristic to be transmitted to the light-emitting diode arrangement 6 in step S9 and transmits the corresponding one in step S5 Signals to the first converter 4 and to the second converter. 5
• the mode of operation of the light-emitting diode module can also be checked repeatedly at specific time intervals in order to determine a new forward voltage or a new forward current for the light-emitting diode arrangement 6, if necessary.

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• Circuit Arrangement For Electric Light Sources In General (AREA)
• Led Devices (AREA)

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• 2007
  • 2007-09-17 DE DE102007044339.2A patent/DE102007044339B4/de active Active
• 2008
  • 2008-09-16 EP EP08802253.8A patent/EP2191693B1/de active Active
  • 2008-09-16 WO PCT/EP2008/007723 patent/WO2009036948A1/de active Application Filing
  • 2008-09-16 CN CN200880107529.6A patent/CN101803457B/zh not_active Expired - Fee Related

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