Systems and methods for testing and characterizing LED lighting devices
Systems and methods for characterizing solid state lighting devices are provided. In certain examples, systems and methods for measuring various parameters of light emitting diodes (LEDs), characterizing each LED based on the measured parameters and selecting one or more of the characterized LEDs such that the emitted light from each of the selected LEDs is mixed with the light from the other selected LEDs to create a desired overall light output are described.
1. A method of measuring and storing LED data comprising:
driving each of a plurality of LEDs with a first predefined drive condition, the plurality of LEDs having data identifying each LED;
measuring one or more selected parameters of each LED when the LED is driven with the first drive condition; and
storing the one or more measured parameters and the first drive condition corresponding to the data identifying each LED.
2. The method of claim 1 , wherein
at least one of the one or more measured parameters is selected from the group consisting of CCT, Duv, luminous flux, spectral power distribution, and forward voltage.
3. The method of claim 1 , wherein
the first drive condition includes one or more of LED temperature, drive current, forward voltage, or duty cycle and a total number of LEDs used.
4. The method of claim 1 , further comprising:
calculating a mixed output of two or more of the plurality of LEDs based on one or more of the stored measured parameters.
5. The method of claim 4 , wherein
the first drive condition is representative of a luminaire and at least a portion of the plurality of LEDs are positioned in the luminaire based on the calculated mixed output to achieve a desired light output of the luminaire.
6. The method of claim 1 , further comprising:
driving each of the plurality of LEDs with a predefined second drive condition;
measuring one or more selected parameters of each LED when the LED is driven with the second drive condition; and
storing the one or more measured parameters and the second drive condition with the data identifying each LED.
7. A method of selecting two of more LEDs from a group of LEDs comprising:
accessing data including, one or more measured parameters of a plurality of LEDs;
calculating a mixed output of two or more of the plurality of LEDs based on one or more of the stored measured parameters; and
selecting two or more LEDs from said plurality of LEDs for positioning into a luminaire based on the mixed output, wherein the data includes a drive condition that includes one or more of LED temperature, current, forward voltage, duty cycle and a total number of LEDs used in the luminaire.
8. The method of claim 7 , wherein
at least one of the one or more measured parameters is selected from the group consisting of CCT, Duv, luminous flux, spectral power distribution, and forward voltage.
9. The method of claim 7 , wherein
the data includes a first drive condition representing a first luminaire having a first light output and a second drive condition representing a second luminaire having a second light output, and the two or more LEDs are selected for use with one of the first and second luminaires based on how close the mixed output matches the first or second light output.
10. The method of claim 7 , wherein
the mixed output is calculated using the equation
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11. The method of claim 7 , further comprising:
driving each of the plurality of LEDs with a drive condition;
measuring, one or more parameters of each LED when the LED is driven with the drive condition; and
storing the one or more measured parameters and the drive condition.
12. The method of claim 11 , wherein
the plurality of LEDs having data identifying each LED that is stored with the or more measure parameters and the drive condition.
13. A method of mixing the emitted light of two or more LEDs for a lighting product comprising:
driving each of a plurality of LEDs with a predefined drive condition;
measuring one or more selected parameters of each of the LEDs when the LED is driven with said drive condition;
storing said measured parameters and said drive condition;
selecting said two or more LEDs from said plurality of LEDs for positioning within a luminaire based on the stored measured parameters and the stored drive condition.
14. The method recited in claim 13 , wherein
the selected parameters include a color value and a flux value and said drive condition includes one or more of a drive temperature, a drive current, and a number of LEDs used in the lighting product.
15. The method of claim 13 , further comprising
calculating a mixed output of two or more of the plurality of LEDs based on one or more of the stored measured parameters and wherein selecting the two or more LEDs is based on the mixed output.
16. The method of claim 15 , wherein
the drive condition corresponds to a typical drive arrangement for a known luminaire and at least a portion of the plurality of LEDs are positioned in the known luminaire based on the calculated mixed output to achieve a desired light output of the luminaire.
17. The method of claim 15 , wherein
the plurality of LEDs have data identifying each individual LED and said data is stored with the one or more measured parameters and the drive condition, and the mixed output is calculated using a weighted average equation,
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18. The method of claim 1 , wherein the data identifying each LED comprises at least one of a unique part number and a serial number.