I’m planning to build a S2+ Triple with SST20 DR 660nm.
I was wondering if I could use a Convoy 5A Buck driver in it?
I’m not sure if the Buck driver will play nice with lower voltage Red LEDs.
What do y’all think?
Question how low voltage that buck driver can give out? Reds works at 2V
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Yeah, that’s the question.
I know Buck drivers lower the voltage output to match the LED but I’m not sure how low it can go or how it determines the needed voltage.
Simon lists them as 3V but the forward voltage of an emitter increases as the current increases so it can’t be a hard 3V limit right?
How do buck drivers determine what voltage is necessary and how can we determine how low it can go?
It’s a range determined by the FB voltage divider and resistor between the Op-Amp output and FB. If the bottom of the range is too high for red leds then you’ll get a minimum that may be too high. Can’t know without trying though.
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You probably know already, Simon uses special buck drivers for SST20-DR and CSLNM1.23 (Vf 2.0-2.5V)
Yeah that’s what I have in the light now, but i want to change it from a single to a triple and 2.5A isn’t enough current
Just guessing, maybe the 17mm 6V 5A boost driver in series configuration? I wound up getting a D4K SST-20 DR boost when I wanted this kind of thing.
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Excellent idea! I completely forgot about series.
Don’t know if this is still relevant, but the answer is yes!
I had a 5A buck driver resistor-modded to 2A for a different project, and tried driving a SST20-DR with it today. I felt motivated to try this after seeing the S12 SST-DR listed with just the 3V 8A buck driver.
The result is that the driver works perfectly with the SST-20DR. In fact, it is better than the 2.5A dedicated red driver because (1) there is no premature LVP bug and (2) the lower modes are more efficient, with more output for the same/less current.
Now I’m planning to build such a triple myself. Did you have any issue soldering the 3030 footprint on a 3535 board?