PhotonWrangler
Flashaholic
Stumbled across this on the net today and thought I'd share it here. What a crazy looking lamp.
Update: found the manufacturer of these beasts.
Update: found the manufacturer of these beasts.
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150 year old lighthouse with a modern lamp
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PhotonWrangler
Flashaholic
I was wondering if they pulsed the individual LED strips sequentially to make the light appear to rotate, but a video of it on the manufacturer's site makes it seem that they flash all of them at once.
knucklegary
Flashlight Enthusiast
Out of curiosity, did you request a quote?
PhotonWrangler
Flashaholic
Lol. Sadly this won't fit in the dome light of my car.
thermal guy
Flashaholic
The one time pwm comes in handy😁
Heat sinks? Any fans involved I wonder.
Looks like the heatsinks are curved, I'm thinking it spins to help for heat dissipation? Would love to see one of these!
Great find!👍
Great find!👍
PhotonWrangler
Flashaholic
The documentation mentions that the user can program "turntable rotation speed" in the controller, so something turns. They mention an adapter to mount to existing lighthouse fixtures. I don't know if this means the existing base turns or the retrofitted lamp does. Theyt also mention that the heat sinking is adequate to operate the lamp in either always-on or flashing mode.
electrolyte
Newly Enlightened
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- Jan 4, 2019
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Wow, thanks for posting that. I've not approached lighthouse illumination for years and never thought about what LEDs might do for it.
It may or may not be obvious that the original strong lamps in these lighthouse were not "flashed", they were eclipsed. When you take the nature of the lamps into consideration, it is obvious why.
If anyone is curious about it, the regulation of lighthouse illumination "period "and "character" is highly organized internationally. Mariners can look up the patterns and know where they are. Note that well-placed dual lighting can aid in steering. The development is certainly interesting since it depended on the available technology. The sounds that the lighthouses made changed with available technology as well. Guess what was used before compressed air horns were invented, yup bells and sometimes...explosives.
It may or may not be obvious that the original strong lamps in these lighthouse were not "flashed", they were eclipsed. When you take the nature of the lamps into consideration, it is obvious why.
If anyone is curious about it, the regulation of lighthouse illumination "period "and "character" is highly organized internationally. Mariners can look up the patterns and know where they are. Note that well-placed dual lighting can aid in steering. The development is certainly interesting since it depended on the available technology. The sounds that the lighthouses made changed with available technology as well. Guess what was used before compressed air horns were invented, yup bells and sometimes...explosives.
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With a use like this it's not likely to use fans. Applications like this prefer reliability over everything else. Many lighthouses are remote or treacherous to reach. The marine environment isn't very kind to anything electrical or electronic. I'd imagine cooling fans would get eaten alive out there.
PhotonWrangler
Flashaholic
Wow! Thanks for the background on this. I had no idea that the "period" and "character" were strictly defined, but this makes perfect sense.
Considering aviation 'borrowed' much from the marine world.
VORs are basically radio-frequency lighthouses for aircraft. 1930s tech that's still in use today.
Like lighthouses, VORs put out coded transmissions which include morse code, so pilots can verify that they're actually listening to the correct VOR. Since pilots have enough other things to remember, charts have the morse code decoded. In this case, GNV. G is two long, one short. N is one long, one short, V is three short, one long.
To be honest, VORs aren't used all that much these days as most pilots will use GPS if available...BUT... the VORs are being kept alive as GPS does have its flaws, outages, and in case of a hostile actor taking out GPS. In those cases, the remaining VORs should be sufficient to keep navigating.
sven_m
Newly Enlightened
Yes, indeed. That's what I was wondering also. How great, the Sealite datasheet mentions the key spec, the luminance: "Nominal Average Luminance (cd/cm2): 1165". That's 11.65 cd/mm2. Curiously, this is the only relevant number for throw in the numerical sense, that is, for max lux in the spot. Different sources may have different diameters, but the lighthouse lense is still same, and so max spot lux only depends on luminance.
On the other hand, in general, a wider spot almost always makes a huge difference for an observer looking out in the field. In this case it's simple: it's important that the spot hits a ship at all: The spot has to be wide enough to reach the horizon (upper edge of spot) as well as a nearby ship in dense fog, which would be quite a bit "under" the horizon from the lighthouse keeper's view (lower edge of spot). The spot diameter simply relates 1:1 to the source diameter. So I guess that's a good bet with the relatively huge Sealite led array.
Important fact: Sealite sources are "designed to replace traditional lamps or lighthouse lights in classical lighthouse optics" [link] . So it's not about competing with todays high performance sources (1-2 kW xenon arc).
Now, according to Thomas Tag's great collection of "lighthouse lamps through time", the light sources originally were candles/oil lamps, followed by acetylene burners, (oil vapour) mantle lamps, and later electric sources (hotwires and ultimately arc lamps). And after reading that page I fully understand what is to be achieved with a sealite source. It's not about challenging performance but about replacing an original, way more complicated, effort-/cost-intensive source.
Yet, what about the throw? What are typical luminance values of classical light sources? As far as I know (and luminance is one of my major interests), typical luminance values of other sources are:
- again, for comparison: the sealite source seems to have a good 11 cd/mm² according to their specs
- candles / oil lamps: about 0.05...0.075 cd/mm²
- acetylene: about 7 times a candle (my own measurement), i.e., up to 0.5 cd/mm²
- hotwire: roughly 1-15 cd/mm²
- halogen hotwire: roughly 10-30 cd/mm²
- carbon arc: roughly 600-1000 cd/mm² (classic arc)
- xenon arc: roughly 500-2000 cd/mm² (modern arc)
Same luminance -> same max spot lux.
Twice the luminance -> twice the max spot lux.
So you have an idea: If I understand it correctly, it's like a good hotwire or a medium halogen hotwire. But probably with equal/wider spot and way less effort. Now we only need a quote :- )Twice the luminance -> twice the max spot lux.
I believe the huge cooling fins just serve a good job even if it's a burning hot summer with no ventilation in the lighthouse. After all it's just 200 W input to the source and roughly 3/4 of that as heat, i.e. 150W. The fins look spectacular but might just serve for chilled operations, without fans (as yet another source of error), and perhaps just also for a good look&feel (marketing ;- ), well I like them.
To compare spot size of the original and the sealite source, we would have to know the very light source which were to be replaced. But for throw (max spot lux), we'd actually only need the luminance, that is, the general type of the original source.
The gaps between the LEDs would be projected into the field with a perfect lense, which could be a problem. But in practice I believe the slight deficiencies of the cylinderical fresnel lens sytem compensate by blurring slightly.
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