Anyone tried building a frankenbebi anchor light?

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Their latest regulator design.
Would that mean no RFI?
 
Lm317 operating as a linear regulator so Rfi minimal.

Should have a 0.1uf cap on the input and at least a 1uf across the output to stabilise ripple especially if you have an alternator on board.

The 317 could be dissipating ( wasting ) quite a bit of power depending on the leds used.
 
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It's a simple application and, despite the hype about the research that has gone into the circuit, it is hardly hi-tech. I'm sure it works and that's probably all that matters, but it could be more efficient. With a bit of care on the buying side component cost should be well under £2 which puts the selling price in some kind of perspective.

If it does the job; fine, but don't be fooled into thinking that it is anything special.
 
Rigger Mortice said:
It's a simple application and, despite the hype about the research that has gone into the circuit, it is hardly hi-tech. I'm sure it works and that's probably all that matters, but it could be more efficient. With a bit of care on the buying side component cost should be well under £2 which puts the selling price in some kind of perspective.

If it does the job; fine, but don't be fooled into thinking that it is anything special.
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As a bit of perspective the original owl was extremely popular among long term cruisers living on the hook, it's nice to see it carrying on as an opensource project.
The components may be pennies but a quick look online points to pcbs being much more, that was just square ones, can you get cheap circular pcbs made online?
Nice to have someone doing some legwork on home made options for potting materials, enclosures etc as well.

Long may they carry on, I say. :cool:
 
Alpha22 said:
So what does it do that a resistor doesn't???
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You could use a resistor if a boat battery could be relied upon to have a fixed voltage but as it may vary from (say) 12volts to 15 volts a resistor would always be something of a compromise. Get it right for 12 volts and the LED's would be over powered at 15 volts. Base the resistor on 15 volts and the reverse would be the case.
 
GHA said:
As a bit of perspective the original owl was extremely popular among long term cruisers living on the hook, it's nice to see it carrying on as an opensource project.
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Bear in mind that this project carries forward nothing from the Bebi Owl except the name and the general shape. They explicitly state that the circuit is their own design, not based on any reverse-engineering of the Bebi original. I'm on my second Owl (sold the first along with the boat it was used on) and very happy with it, but I wouldn't automatically buy one of these if I ever needed a replacement.

Pete
 
The LM317 current regulator is a fine current regulating circuit ensuring constant current through a range of input voltages.
However the LM317 will in itself drop over 2.5 volt plus in current control circuit it needs to drop 1.25 volts through the current sensing resistor R1. Now each LED will need about 2.5 volts to operate and there are 3 in series in each leg. If these figures are correct you will get no light at an input voltage less than about 11.25 volts. I suspect even higher voltage for drop out. If you want this current regulation the best option is to use only 2 LEDs in series in each leg. This will hower reduce the efficiency of the light by 33%.
(need more LED diodes)
I would reckon that most people using an anchor light would be running on a lead acid battery of about 12v possibly going lower throught the night. It would I think be unusual to be running on a battery which is being charged. ie 15 volts when using the anchor light.
As such I think the simple series resistor type regulation is adequate for an anchor light.
Now the simplest waty to acheive a mechainally mounted series of LEDs with a suitable series resistor is by buying an LED bulb from China. very cheap and available in a range of wattages. (brightness) Here is a n example. http://www.banggood.com/Wholesale-Car-G4-9-LED-SMD-5050-Warm-White-Light-Bulb-Lamp-12V-p-26010.html
Here is a very bright high power bulb http://www.banggood.com/Wholesale-G...Lamp-DC-12V-6W-510-LM-Pure-White-p-52522.html These little tackers would probably do quite well. http://www.banggood.com/10X-G4-5-LE...Marine-Boat-Light-Bulb-Lamp-12V-p-910381.html
I found that id you remove the LED on the end you can increase the current through the rest of the LEDs which would be OK for running ona non charging battery. These are amde for cars so designed for 14v supply. You will see a huge range of bulbs.
Now all you have to do is fit the bulb in a water tight container with attachment on top to hoist into the rigging. Use a small glass jar.

The circuitry of the frankenbebi shows also a secion for on off switching in daylight. This should work quite satisfactorilywithany LED bulb. So delete the LM317 and R1 and connect +ve supply to the LED bulb. (assuming LED bulb gas has it's own series resitor. If you are using bare LED (diodes) then you will need a series resistor. Incidentally bare LEDs can be cut froma string of white christmas type LED lights. A bit tricky however to mount. A piece of plastic pipe about 50mm diameter can be used. drill 5mm holes for the LED to be pushed through from inside. Range the holes around the circumference to give 360 degrees of cover. Use a min 6 LED preferably more. (in multiples of 3)
I have not experimented but I think if you use the daylight switch then the light sensor transistor T1 will have to be isolated (light wise) from the LEDs to ensure the LED light does not make the transistor think it is daylight. So one jar for lights one on top for the light sensing transistor would be my suggestion.
All good winter fun PM me if anyone is confused olewill
 
William_H said:
The LM317 current regulator is a fine current regulating circuit ensuring constant current through a range of input voltages.
However the LM317 will in itself drop over 2.5 volt plus in current control circuit it needs to drop 1.25 volts through the current sensing resistor R1. Now each LED will need about 2.5 volts to operate and there are 3 in series in each leg. If these figures are correct you will get no light at an input voltage less than about 11.25 volts. I suspect even higher voltage for drop out. If you want this current regulation the best option is to use only 2 LEDs in series in each leg. This will hower reduce the efficiency of the light by 33%.
(need more LED diodes)
I would reckon that most people using an anchor light would be running on a lead acid battery of about 12v possibly going lower throught the night. It would I think be unusual to be running on a battery which is being charged. ie 15 volts when using the anchor light.
As such I think the simple series resistor type regulation is adequate for an anchor light.
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Maybe that applies to most people but it's worth bearing in mind in the case of both Bebi, and by the looks of it these guys, that the unit is designed by long term cruisers for use on a long term cruising boat. On which sailing is only an occasional pastime, mostly what happens is trying to stop things breaking and fixing things which have broke :)
Which means no regulation on any LED's is a bad idea, sooner or later a seagull will poop on the light sensor just before a good 16v battery equalizing charge or forget to turn the light off on a windy night time equalizing session. Also, batteries getting down below 12v overnight will probably be on the way to the bin.
For the sake of a few pennies on a chip in this case it's probably a bad idea.
 
Salty John said:
The Davis Mega-Light isn't LED. But, you can add a 9xLED 'bulb' to make a very good quality LED anchor light out of it.
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"Mega-Light™ Utility
This LED low current light features a light sensor that automatically turns on at dusk and off at dawn."

Perhaps the low power "bulb" is LED and the brighter one is an ordinary filament light?
 
JumbleDuck said:
Is this likely to be much better than a Davis Mega-Light, which is also LED and daylight-sensing?

http://www.davisnet.com/marine/products/marine_product.asp?pnum=03300
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Probably. Everything is encased in epoxy on the frankenbebi so should be completely waterproof with no lens to smash.

But unless you want to build one yourself it might be hard to get hold of one for a while yet to find out...

Though without the light sensing the regulation circuit is dead easy so self build shouldn't be difficult. Bit annoying but they don't spec the LED's other than ..

Following the design of the original OWL the LEDs are a T-1 package type (2 leads for thru-hole PCB mounting, 2.54mm OC) with a 5mm diameter. The LEDs are manufactured by Cree, a major US based manufacturer since 1986. As there are variations in output even in tightly controlled manufacturing environments, major manufacturers offer "binning" or sorting of a particular LED series by output and color spectrum. There is an "upcharge" for binning but we have opted to purchase binned LEDs in order to be sure all the components used meet the requirements of 33 CFR 84.13 - Color specification of lights and 33 CFR 84.15 - Intensity of lights. According to table 5 in 33 CFR 84.15 the minimum visibility of the FrankenBebi at the drive levels we are using should be in excess of 4 miles
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.

Google came up with this from the original manufacturers...

The ‘flat’ (SMT) devices [as used on UltraLEDs' lights] aren’t exactly what they seem to be at first glance, or we would be using them.
First, their light output per energy consumption isn’t any greater than the devices that we’re using, there is just more light generated from fewer devices. In fact, although the difference is trivial in any sort of meaningful measurement, the Nichia DS series of devices [ie. the ones used by Bebi] are still the most efficient LED devices in converting electrical energy to light energy in production.Luxeon [the first manufacturer of the flat / SMT devices] specifically does not recommend using their devices in exposed locations.We require that the leads are silver-plated copper, instead of the more common tin plated steel. [This makes the units more water resistant and so more suited to the marine environment.]
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prv said:
Well, if it's possible to get such performance from incandescents, why did we spend all but the last decade or so putting up with 25 watt tricolour bulbs that flatten your battery in a night's sailing, instead of 1.2 watt ones?

Pete
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I don't know, but the Davis, and the Chinese copy you see from time to time at around £12, come with two incandescent bulbs, low draw and high draw. I don't know if anyone has ever checked their range but they both have quite a good Fresnel lens.

We used to sell the Davis and then we started making an LED anchor light using the Chinese body and lens. We used a Super Bright 9x LED bulb, we added an extra O ring and a different cable gland otherwise they leak badly, and it was a very good anchor light. Adding an LED to the Davis Mega Light gives you an excellent anchor light, but quite expensive. Or buy the Chinese one, add the LED, tape the joint between lens and body and put a shot of silicone into the cable gland hole and you'll have an excellent light quite economically. Never need to open it, it will last 15 years or more if used every day.

But don't buy the Davis thinking you're getting an LED light, you're not.
 
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