Hi all and thanks in advance for your time !
I am currently designing an LED light sources that has 4 individual strings of LEDs, to be controlled by a commercial constant current machine vision driver (Smartek HPSC4). One of the strings has significantly less LEDs than the others (3 vs 8, 9 and 14). The driver works best when the voltage drop across all strings is similar, and this discrepancy is causing issues, so I need to increase the voltage drop on this line, but can't add more LEDs because of space constraints and to avoid wasting extra (expensive) LEDs.
For this purpose, I am considering adding diodes in series to this string, as a way to increase the voltage drop, without limiting the current that could go through it. However, I am unsure of the side effects that this could bring, especially as the LEDs are strobed at high-current and high-frequency with very short on-times (1500mA and about 20µs ON vs 200µs OFF) so I would not want to introduce too much extra rise time etc.
EDIT : The HPSC4 driver effectively acts as 4 independent drivers, and each string here is attached to one channel of the driver. All strings are completely independent and each driven by their own constant-current sub-driver.
Please, feel free to let me know how this sounds or if there is a better solution out there![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
Best regards,
Adrien
I am currently designing an LED light sources that has 4 individual strings of LEDs, to be controlled by a commercial constant current machine vision driver (Smartek HPSC4). One of the strings has significantly less LEDs than the others (3 vs 8, 9 and 14). The driver works best when the voltage drop across all strings is similar, and this discrepancy is causing issues, so I need to increase the voltage drop on this line, but can't add more LEDs because of space constraints and to avoid wasting extra (expensive) LEDs.
For this purpose, I am considering adding diodes in series to this string, as a way to increase the voltage drop, without limiting the current that could go through it. However, I am unsure of the side effects that this could bring, especially as the LEDs are strobed at high-current and high-frequency with very short on-times (1500mA and about 20µs ON vs 200µs OFF) so I would not want to introduce too much extra rise time etc.
EDIT : The HPSC4 driver effectively acts as 4 independent drivers, and each string here is attached to one channel of the driver. All strings are completely independent and each driven by their own constant-current sub-driver.
Please, feel free to let me know how this sounds or if there is a better solution out there
Best regards,
Adrien
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