Now that I’ve finished my E4000 floor lamp mod (one of these days, I’ll take pics), it’s time to start a new project. I’ve always wanted some motion-activated floodlights so I figure this will give me a reason to play with some C9000s. I haven’t yet decided on a fixture but I’m not overly fond of the LED floodlight design that you see on ebay and on most importer websites so I’ll probably modify a dual-head 500W halogen fixture or a pair of HPS fixtures (mounted in the same spot but pointed differently). But while I’m deciding on a fixture, I need to start thinking about viable power options that won’t break the bank.
0. Wiring the LEDs in series is probably a non-starter since it would require a 60-65VDC power supply…
1. Dedicated 100W CC power supply per LED. Something like a Mean Well HLG series. This would be fairly spendy. Advantages would be balanced output and simplicity: rated IP65 or IP67 (depending on whether you want internal adjustment pots) so it wouldn’t necessarily need any protection from the weather so the power units could be mounted on or next to the fixture themselves.
2. Wire the LEDs in parallel and power them from a single CV power supply. Advantages: cuts power supply costs by 50%. Could use a 240W MW HLG series mounted next to the fixture. Disadvantage is the floods will probably have unbalanced output. Taking the E4000 as an example, Bridgelux’ specs claim 2.1A @ 24.4V is typical. My particular LED, however, draws 2.5A at 24.4V. I assume similar range of Vf values exist for the C9000 so one LED would probably be noticeably brighter/hotter than the other.
2a. Could add a 100W DC-DC driver to each LED to balance the output. More complicated but shouldn’t be too much more expensive. IIRC, texaspyro found some serviceable DC-DC converters on ebay for relatively cheap. The converters likely won’t be weatherproof, though, so they’d need to be protected.
3. Single remote CV power supply with DC-DC driver at at each LED. Disadvantages: more complicated, cost and possible electrical code issues. Advantages: flexible power supply choices (unprotected units would need an enclosure). Using DC-DC boost converters would mean I could use more readily-available 24V power supplies. Could conceivably choose a bigger power supply and with an appropriate enclosure/panel, power not only floodlights but possibly also cameras and landscape lights.
I’m leaning towards 2a but I’m very much open to recommendations from those who’ve done this before…