Triple trouble - emitters not equally bright
Triple trouble - emitters not equally bright
Hi All,
I recently built my first 2x S2+ triples with KD SST20 MCPCBs and Convoy 5A drivers. On one of them I noticed, when at 1%, 1 emitter is noticeably dimmer than the other 2. My second triple I changed the sense resistor to provide slightly more amps and that one is fine.
Anyone experienced this? Could it be a bad mcpcb, driver/level issue?
It could be a bad reflow, but it's common for one to be brighter at moonlight because of forward voltage tolerances
common for one to be brighter at moonlight because of forward voltage tolerances
Interesting, I would never have guessed. Glad my TS10 doesn't show that even at level 1 brightness.
Experience like this is why this community rocks. Intrigued by Adair21’s answer, I read around the web to understand better - I didn’t realise there could be so much tolerance in LED forward voltages!
As a result, when in parallel/at the same drive voltage, different currents drawn = different relative brightness. Outside of independent resistors, you’d need to get lucky with matched emitter tolerances or just run above moonlight so that the difference is less noticeable.
Maybe it’s a reflection of the cost of the KD boards?