First off, thanks for posting some difficult-to-obtain information on the other thread , I’m a ZL fan, but never had any modded, or tried to take them apart myself, so the details of their “legendary efficiency” has always been a magic black box. I’m an EE, so it’s definitely interesting to have some data sheets to read, now. I’m not clear how they do the CC control with those chips or what other cleverness they might have, but it’s cool to know something.
It’s interesting that there’s at least one level that the 53’s spec shows it as more efficient. The 53 says 30lm for 21h, the 5 says 21lm for 21h. I have my doubts about the 30lm.
At the lowest high the 53 spec is 122lm/4.2h=29 lm/h vs the 5 at 166/2.8=59lm/h. Kind of suspect, since if the 53 is ~60-70% efficient, then at best, a 90% efficient driverf would give you 50% more lm/h, not double. Maybe you can’t use the numbers that way for an accurate comparison.
I picked up a second SC5 since it seems to be on the discontinued list, now, though still in stock. I didn’t know the chip was that much niftier, so I’d like a spare.
My 53w will be in the shop for 3-4 months on warranty repair, as it seems to have a problem on M1 where it’s drawing 3x the current (~1.2A vs 0.4A) vs M2 instead of the H53 and SC53c where it’s double (~0.8A vs 0.4A), and rough light-meter measurements tell me the ratio of M1 to M2 is about 2:1 for both lights. M1 and H4 are probably my favorite modes. I’d hate to be burning off 400mA for nothing at M1. Not sure what could be wrong with the circuit to cause an efficiency dip that bad in the middle of the range, but for $4 shipping, I’ll get it fixed.