LED Anchor Light

[Amnesia II]

Originally Posted by dugout

This is too funny. You have never seen one of these lights. You are arguing based on theory with folks who have real experience with Bebi lights.
The Bebi lights represent one of the absolute best values in marine lighting of any type with a real lifetime warranty. There effectiveness is demonstrated in any anchorage. The lights are bright and they last seemingly forever.
Buy what makes you happy.

Absolutely! I had the pleasure of meeting the Bebe crew in Savu Savu, Fiji, very helpful and a wonderful location.

In a large anchorage...returning to my boat, I look for the brightest anchor light...it's usually mine!

[scoobert]

Originally Posted by noelex 77

If you install a Bebi Owl you will find that your your boat invariably has the brightest anchor light when sharing the anchorage with other boats.
However, It is certainly possible to build an anchor light that is brighter, even much brighter.

Using Luxon Rebel emitters to make a home made anchor would work well. The difficulty is designed and producing an optical system that would direct the light where required (like the commercial lights that use these emitters have)
It is possible to ignore the optical system and simply generate more light.
Three or four good quality Luxon Rebel emitters, would make a very bright anchor light and I have thought about doing something similar. The difficulty is without a suitable optical system would be the power consumption, even under-driven, it would be much higher, negating one of the major advances of the led anchor lights.

When considering a better anchor light rather than just focusing on brightness give some consideration to installing a light (s) where it can illumate some of the superstructure. This avoids confusion with shore light and makes distance judgments much easier for boats entering the anchorage.

A 2 mile anchor light at the top of the mast with a couple of the rebel emitters mounted as deck lights underneath the spreaders would be good solution. In this application the light of the emitters is directed where needed, so the efficiency is high. It is legal and makes you far more visible than much brighter anchor light at the top of the mast.
The main drawback with this approach is that dark adaptation is lost making it difficult to keep track of other boats in the anchorage that may be dragging.

when i was working to create a lightbar halogen rotatory light LED replacement i played with 5MM and 8MM LEDs.
i found at distance, in daylight, they were a joke. i guess at night they may be preferred.

for mast lighting you could mount upward facing LEDs on the spreaders. with the luxon your voltage will determine how many... i think they were 3.3 volt, so i used 4 in series. and let me say, 4, in broad daylight were visible at over a mile, and that was my goal. but today, 3 years later, they may offer different drivers that will give you more flexibility.

perhaps once i move aboard full time i will have the time to make it commercially viable to produce marine lighting solutions. thou i will have to someday see these 5MM LEDs in a pvc cap.

[noelex 77]

Originally Posted by scoobert

for mast lighting you could mount upward facing LEDs on the spreaders. with the luxon your voltage will determine how many... i think they were 3.3 volt, so i used 4 in series. and let me say, 4, in broad daylight were visible at over a mile, and that was my goal. but today, 3 years later, they may offer different drivers that will give you more flexibility.

You cannot drive LEDs like the Rebel simply by connecting them in series with the boats power supply. The result will be very poor brightness, poor life or probably both.
Driver circuits are easily built, but considering the low price I usually buy a ready built unit.

Even the cheapest commercial units will have such a driver and if you want to produce anything better you will certainly have to incorporate such circuitry.

This is older model from some forgotten project I dug out of my junk pile to show you what's available.
It will supply a constant current (which is what these LEDs need) adjustable from .3 to 1A

[scoobert]

Originally Posted by noelex 77

You cannot drive LEDs like the Rebel simply by connecting them in series with the boats power supply. The result will be very poor brightness, poor life or probably both.
Driver circuits are easily built, but considering the low price I usually buy a ready built unit.

Even the cheapest commercial units will have such a driver and if you want to produce anything better you will certainly have to incorporate such circuitry.

This is older model from some forgotten project I dug out of my junk pile to show you what's available.
It will supply a constant current (which is what these LEDs need) adjustable from .3 to 1A

nice little unit. wonder how the endurance is?

[goboatingnow]

Philips Rebel Automotive have some nice stats that might translate well into boat use.


dave

[RaymondR]

I am not sure that you can apply the 4.3 candela requirement to LED lights. The candela thing is a measure of the total luminosity falling upon a 1 ft by 1 ft square spherical surface from a 1 candle power source situated 1 foot away from the surface.

LED lights do not illuminate spherically from a point source, they illuminate from a source situated on a flat plane in the chip which is spread to conical by a lens. That is, all the light produced is concentrated into the cone and not propagated spherically.

I think LED illumination is more analogous to that pertaining in the old light houses where the light from a relatively small gas or oil lamp was concentrated into a beam using lenses which could be seen at long distances.

As a consequence of the concentration of their light into a beam, multiple LED lights can be used to implement an anchor light as visible at a distance as incandescent lamps of much higher wattage. The narrow angle of the cone does not cause problems re height of the observer as we are all pretty well at sea level.

Have a look at the table below and you can see the significance of the 4.3 figure in the Intensity of Light section.

[noelex 77]

Originally Posted by RaymondR

I am not sure that you can apply the 4.3 candela requirement to LED lights.

Luminous intensity measured in candelas takes into account the concentration of light that is present in the 5 mm LEDs.

The lumens indicate the total amount of light that is given out, luminous intensity measured in candelas gives an idea of the brightness of the light in one particular direction.

Thus luminous intensity is what is important in an anchor light which is why this value is specified.

[noelex 77]

Originally Posted by scoobert

nice little unit. wonder how the endurance is?

The drivers are normally very reliable. Importantly they make the emitters much more reliable by driving them at the correct current.
Overdriving the emitter drastically shortens its life and this together with poor heat disipation is responsible for most led failures.

[RaymondR]

OK, thanks for the explanation, I probably should have pondered it a little more myself before breaking into print.

I have not built an anchor light for a few years and consequently have not looked at what is available for a while. Doing so now I notice that the least light output for a 5mm LED in the catalog I have is 4000mcd with a 30 degree spread and the largest 45000 with a 15 degree spread at 20 and 30 mA respectively. Considering that it is not so many years ago since the white were introduced the light output increase they are achieving with these things is incredible.

I have found that LED garden lights, whilst pretty useless as anchor lights, are a good source of reflectors for building your own single LED anchor lights.

[scoobert]

Originally Posted by noelex 77

The drivers are normally very reliable. Importantly they make the emitters much more reliable by driving them at the correct current.
Overdriving the emitter drastically shortens its life and this together with poor heat disipation is responsible for most led failures.

indeed. out of the 50 i bought for experimentation, about 12 survived.

[RaymondR]

I seem to recall that they can take a couple of orders of magnitude more current in very short pulses and that this was one of the reason for the implementation of the oscilator/decade counter device when they were only available with comparatively low light output.

[cal40john]

Originally Posted by svadagio

Hi
The problem is not the bulb but your power. After a friends bad experience with LEDs I did some research. LEDs are very sensitive to voltage changes. The normal range on a boat with battery low to absorb charge is about twice what they can stand.
What I did and I have used Dr LED bulbs which are poor for 4+ years now with no problems for all my nav lights is to provide a constant 12 volts to the lights. The parts are readily available from Digikey or Mouser for less than $5.00. Simply build a regulator capable of the total amperage your lights will need and put it in the circuit. More work than putting a bulb in but less money and in the future you can use what ever you want if caught some where you can not get that special one. Hint, build the reg so it will power incandescent bulbs in case.
Bob

You didn't need to do that for Dr LED. As others have stated many LEDs have built in circuitry. At boat shows he used to have a variable voltage power supply that he would crank from low to high voltages, had an ammeter showing constant current consumption over the entire range and no change in light output.

From page 23 of http://www.doctorled.com/DrLED_Marine_Catalog_0911.pdf

Internal circuitry provides for constant current consumption, regardless of voltage fluctuations from the source (11
to 15 VDC), meaning no flickering and longer LED life

[gspeak]

Have bought a Mega-Bright Anchor Light from Cruising Solutions as an addition to my unknown brand LED mast head anchor light. Use it to add light to the cockpit as well as a cockpit height anchor light as it also has an inbuilt photocell turning it on & off with nightfall & daybreak. It uses about 0.04A, is very bright & is waterproof.

No connection with them ... just a happy shopper.


Dave

Seabreeze, Lagoon 380 #241

[scoobert]

Originally Posted by gspeak

it also has an inbuilt photocell turning it on & off with nightfall & daybreak. It uses about 0.04A, is very bright & is waterproof.

No connection with them ... just a happy shopper.


Dave

Seabreeze, Lagoon 380 #241

i have not had a daylight sensor that lasted more then a few years, i am always leery of those. just make sure it keeps coming on if you use it as the primary anchor light.

[goboatingnow]

Originally Posted by scoobert

i have not had a daylight sensor that lasted more then a few years, i am always leery of those. just make sure it keeps coming on if you use it as the primary anchor light.

I rigged up one to turn off my anchor light , but it connects in at the panel and the sensor is nearby. Works good

Dave