Homemade LED anchor light circuit

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GHA

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Came across this youtube which suggests a similar but improved circuit to the frankenbebi one.. http://www.ybw.com/forums/showthrea...rankenbebi-anchor-light&highlight=frankenbebi

https://www.youtube.com/watch?v=Opm-3-hkDEM

Selection_003_zps55617c0f.png

So getting a few bits from mouser and substituting a STP16NF06 power MOSFET for the transister it seems to work fine. LED's are about 20p each, the MOSFET 47p and voltage reference 36p. +vat.
http://uk.mouser.com/Search/m_Produ...tualkey57280000virtualkey941-C503DWANCBBDB152


I had a circuit rigged up on a bit of breadboard just now putting out a very stable 30mA down to 10v.

Delivery is steep though, 12 quid. Even so, with a few people clubbing together a bright low power anchor light could be yours for little cash and a little bit of work.

Frankendebi seems to have gone quiet unfortunately
http://frankenbebiproject.org/
 
Farnell might be free delivery?
Or Rapid perhaps?

Personally I don't like going to a lot of effort to regulate the total current, when the current sharing is hit and miss.
As I have yet to find a problem with my crude one with just a resistor for each string of leds, I won't prioritise find the perfect solution.
I waffled on , on the last thread.
That's professional (?) stubborness, so long as it works, go for it.
A light that you won't worry about flat batteries is good to have when things start falling apart!
 
COLREGS on the subject of anchor lights:
(a) In vessels of 50 meters or more in length:
•a masthead light, 6 miles;
•a sidelight, 3 miles;
•a towing light, 3 miles;
•a white red, green or yellow all-around light, 3 miles.
(b)In vessels of 12 meters or more in length but less than 50 meters in length;
•a masthead light, 5 miles; except that where the length of the vessel is less than 20 meters, 3 miles;

The last line says if your vessel is less than twenty meters then a 3mile anchor light is required. On boats with LED lights I have never seen an LED light that can be seen more than half a mile away, so check the distance your light can be seen before fitting it.
 
KellysEye said:
COLREGS on the subject of anchor lights:
(a) In vessels of 50 meters or more in length:
•a masthead light, 6 miles;
•a sidelight, 3 miles;
•a towing light, 3 miles;
•a white red, green or yellow all-around light, 3 miles.
(b)In vessels of 12 meters or more in length but less than 50 meters in lenygth;
•a masthead light, 5 miles; except that where the length of the vessel is less than 20 meters, 3 miles;

The last line says if your vessel is less than twenty meters then a 3mile anchor light is required. On boats with LED lights I have never seen an LED light that can be seen more than half a mile away, so check the distance your light can be seen before fitting it.
Click to expand...

Ah! But, a Masthead light is not the same as an anchor light. Strangely, a Masthead light (or what we commonly call a Steaming light) doesn't have to be at the masthead. Anchor light for vessel between 20 and 12 metres, visibility - 2 miles. (Rule 22, ).
 
KellysEye said:
COLREGS on the subject of anchor lights:
(a) In vessels of 50 meters or more in length:
•a masthead light, 6 miles;
•a sidelight, 3 miles;
•a towing light, 3 miles;
•a white red, green or yellow all-around light, 3 miles.
(b)In vessels of 12 meters or more in length but less than 50 meters in length;
•a masthead light, 5 miles; except that where the length of the vessel is less than 20 meters, 3 miles;

The last line says if your vessel is less than twenty meters then a 3mile anchor light is required. On boats with LED lights I have never seen an LED light that can be seen more than half a mile away, so check the distance your light can be seen before fitting it.
Click to expand...

Eh? In any anchorage these days the brightest anchor lights will likely be LED's. Maybe a decade ago there would be some dim ones about but these days there's little chance from a purpose built as opposed to a replaceable bulb. It's a win win, brighter and lots less current than an incandescent.

Anyway, the calcs apparently come out at 4nM for these LED's driven at 20mA.

3. Using the values specified in CFR33 84.15 Table 84.15(b) and the absolute minimum bin output value at the 21.5mA drive level we are using will be in excess of 4 miles (27 candelas) Typical output at 21.5ma is closer to 32000mC per led. Beam-spread overlap at distances exceeding 200 meters should raise perceived intensity to the 45000mC range.
Click to expand...
 
I just fitted a 12v LED Lamp into the existing fitting, hung up forward on the spinnaker halyard and plugged into the 12v cigarette lighter. Lamp from ebay, works well and very visible.
 
GHA said:
Eh? In any anchorage these days the brightest anchor lights will likely be LED's. Maybe a decade ago there would be some dim ones about but these days there's little chance from a purpose built as opposed to a replaceable bulb. It's a win win, brighter and lots less current than an incandescent.

Anyway, the calcs apparently come out at 4nM for these LED's driven at 20mA.
Click to expand...
The light I made ages ago is probably much lower in terms of candelas, but it's generally at least as visible as you average yacht's all round white.
I don't often anchor anywhere where I need to be seen from a mile or more away.

Fair point that we ought to do the sums.
 
My Triton anchor light, with nine LEDs, was measured by the UK supplier to be visible at two miles and subsequently by myself at the same distance. I now use a self-contained light, solar panel charged and automatically switched, that is also clearly visible at two miles. I believe this one to have a single LED.
 
These little devils are to my mind brilliant for an anchor light or anything else. Indeed I have one with the end LED and one side reoved as a stern light and it is very bright.
It is fairly easy to remove one of the 5050 LEDs with soldering iron so giving just 360 azimuth. The slightly higher cirrent for remaining LEDs due to common resitive current limit is good on the basis that you will only have 12v in the battery when at anchor. Mr Banggood has a huge range of very cheap LED lights free postage so you can fiddle though winter. You can use the light sensing circuit or just make it turmed off when not needed. good luck olewill
http://www.banggood.com/10X-G4-5-LE...Marine-Boat-Light-Bulb-Lamp-12V-p-910381.html
 
I have a home made LED anchor light, a bulb in a piece of perspex tubing, all cemented together so watertight. As it is LED I will never have to replace the bulb. Hang it from the boom or from the inner jib halyard. It is invariably the brightest anchor light around.
 
with a bit more playing around and some veroboard..

Using just a single string of 3 of the cree LEDS , driven at 25mA (as low as I can get with a 50ohm pot in the circuit) , current is stable down to about 10.5v input voltage and input current is about 27mA at 12.5v.

Bright little things if you look straight at them.

If anyone wants a play I've some mosfets and tlv431 shunts spare.
 
Just in case anyone is actually interested, it's very easy to control this circuit with a voltage onto the left of 1K resistor. I've just been playing around using an arduino, PWM works so you can fade in and out, program in some morse or have it blip once in a while to make it easier to find your boat in a crowded anchorage.

If that's what you want :)


Selection_003_zps55617c0f.png
 
Look out for the next PBO magazine, which is to feature a simple home made automatic anchorlight. or; Bedazzled offer a very good replacement led bulb with integral automatic on/off function, approx £13 if I recall.

All Bedazzled bulbs are ruggedized and protected for use in marine environment.
 
maxi said:
Look out for the next PBO magazine, which is to feature a simple home made automatic anchorlight.
Click to expand...

I was given this circuit diagram by, if I recall, a forumite many years ago. I have now built two of them, one with a conventional bulb and one with leds. I know next to nothing about electronics but it was an easy build on Vero board.

anchorlight.jpg


PS: the 10K pot adjusts the sensitivity to light ie changes the time it comes on and goes off.
 
Last edited:
alahol2 said:
I was given this circuit diagram by, if I recall, a forumite many years ago. I have now built two of them, one with a conventional bulb and one with leds. I know next to nothing about electronics but it was an easy build on Vero board.

anchorlight.jpg


PS: the 10K pot adjusts the sensitivity to light ie changes the time it comes on and goes off.
Click to expand...
The collectors and emitters are the wrong way round!
I looked at that for a while, didn't look right, couldn't see why.
 
lw395 said:
The collectors and emitters are the wrong way round!
I looked at that for a while, didn't look right, couldn't see why.
Click to expand...

I told you I know nothing about electronics... I've been investigating (as far as my limited knowledge will allow). The BFY51 is apparently an NPN transistor so have I just got the position of the arrowhead in the wrong position (and the letters in the correct positions) or have I got the arrow in the right position but the letters in the wrong position?
 
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