LED Cabin Lights

[sneuman]

I recently boat an LED cabin light (bayonet-style) and properly installed it (no x'd polarity) in the socket. It worked fine for a few days -- the light was acceptible if not exceptional.

Then, it started to dim and blink on and off (batteries fully charged). Is this just a dud or what?!

[Fishman_Tx]

Possibly, there are some other components on some of these besides the LEDs. Do you remember the brand and part#?

[sneuman]

Anchor brand LED cluster light.

[Solitude]

lemon? send it back.

[gonesail]

the LED is very sensitive to over voltage .. but anchor should have built in protection ..

[scotte]

Wiggle the bulb, maybe just not getting good contact in the socket.

[Fishman_Tx]

Ok , "Ancor" not Anchor, correct?
One of these?

Usually, cluster LEDs will have dropping resistors or "driver" or both built in, dependant upon design. I'd say if the socket is putting out what it should and it works with a standard bulb, then you have a dud or burnout. Gonesail is correct that LEDs can be sensitive to overvoltage but as a commercial product, should be protected with sufficiently rated dropping resistors to handle MOST cases. The single contact product is designed for 12vdc with a range of 13.5vdc at 10ma. The double contact (both models) is 12vdc with a range of 10.5 - 15.8vdc at 80-160ma (qty of LEDs determine the current usage). If using the single contact model I would say trouble is possible at or above the rated 13.5v. If your float from the charger is at or above this, yup you got troubles.
If a single contact socket, change the socket to a dual. unfortunately, without the spec sheets(unavailable at Marinco/Ancor) it's hard to determine the "pinout" requirements. You could call them. Here's the site:
http://www.marinco.com/

[PneumatosII]

LED's are sensitive to getting too much current, and ones with driver circuits can be sensitive to over voltage and spikes (from lightning, motors shutting off etc). For this reason, I try to install surge supressors at every sensitive device, including LED lights, radios etc. I use a rather simple, cheap method. From Digikey or other supplier, you can order Metal Oxide Varistors for under $1 each. Get ones that are rated as close to 14V (max normal V when charging) (but above) as possible, and with as much "energy potential" (joules; how much zap they can take before frying). Put these across the hot and ground, and install a small fuse upstream (+ side, on the batery side of the MOV). When a voltage spike comes along, anything above the rated clamping voltage will be shorted out through the MOV, and if it is too much, the fuse will pop to protect the MOV. I have used this arrangement on my phone lines (we live on a mountain so get lots of lightning) and they have saved many phones. When desiging discrete LEDs with a simple dropping resistor, I use 4 red LEd's in series with a 330 ohm dropping resistor. You have to check the voltage drop of the diodes, add them up, subtract total from 14V (max expected) and then using V=(current)X(Resistor), solve for a current somewhere below the Imax current and that is your resistor (I shoot for about 10-15 milliamps). The larger the resistor (so the fewer the LED's) the more tollerant the LED's are to over voltage. Hope that's not too techie, but when you can buy bulk LED's off ebay for about $0.05 each, I can't stand paying the price for "marine LED fixtures". To make fixtures, just solder the LEDs and resistors, press them into modeling clay to get correct shape and position, then RTV the wires and diodes (not the fronts) so they stay in place. This worked well for my running lights, as I could get a nice, even spread. BTW, buyng conventional fixtures and replacing the bulbs with LEDs gives you the advantage of carrying spare incadescents for emergency (cheaper), but with this, you can't utulize my favorite advantage of LED lighting: using cheaper and smaller 18-22ga wire to power everything. I recently was able to add a red "night light" with a single LED, tiny wires and just RTV'd it on the inside of a spotlight fixture.

[Fishman_Tx]

Re: MOV on LED - Don't you think thats a bit overkill? Eh, whatever floats the boat. But you know the saying, a $35 microchip will protect a 10c fuse by blowing first. (Murphy's Law of Random Perversity)
PneumatosII
Have you worked with the Luxeons yet? If you don't mind sharing, I'd like to see some of your designs or ideas. I'm looking for some creative solutions to spreader lights and port/starboard floods, possibly using the new Altilon which is a forward illuminating LED for automotive daytime running lights. PM me if you'd like. Thx!

http://www.philipslumileds.com/pdfs/PB66.pdf

[PneumatosII]

In the words of a credit card commercial: MOV's; $1. Fuse and holder; $2. Not loosing a $30 LED fixture at a bad time or having to climb the mast to replace it; priceless.

As for the Luxeon bulbs, I haven't researched these much, but I know some of the new generation LED's are power and temperature sensitive, so require driving circutry to drive them properly. I use $25 units from Cruising Solutions for my interior lights, mostly because of nice light temperature (these are the ones I protect). As for deck lighting, I too am trying to get rid of my power-hungry spreader bulbs. I found some units made from discrete led's (21 of them) already in a neat 12V sealed package for $1 on ebay. They seem to be OK on light output, but for the price, I can afford to put several at various angles. I am a firm believer in simplicity, and discrete LED's with dropping resistors seems much less complicated than the bleading edge LED's with regulators and temperature sensors trying to push the new devices to their limit. IMHO.

[forsailbyowner]

What mcd rating are you getting for 5 cents apiece? Found some 10 mm 15000 mcd for 30 cents I thought was a good deal. They also have 14 "superbrite" leds that fit a G4 socket 12v $8.95 and 12 led strip 12v 230 mcd apiece $12.95

[goboatingnow]

Theres a lot more to driving LEDS then just a dropping resistor. Hi-Brite LEDS really need constant current driver electronics as well as auto current adjust to compensate for aging. Otherwise their life can be very short indeed. The industry is full of cheap crap LEDS which have appalling MTBF's

[PneumatosII]

The cheap ones were 21 LEDs in a fixture for $1 from some Hong Kong company (+ $3 shipping). The light is the old cool white/blue, so not ideal, but for a spreader light... It was also very focused, so I think it would have to be up there about 25' to be of much use. Where did you find the $0.30 ones? Superbrightleds.com has some; not sure of price.

As for "driving" LED's, the constant current drivers etc. are a bit of a luxary which the new "high output" luxeon etc. bulbs need, but the old cathode/anode type don't (though they certainly could benefit, I guess). I am a fan of 'as few semiconductors on the boat as possible' as they tend to be more sensitive to surges from lightning, etc. The old 5mm LED's in an epoxy pkg use the case for heat disipation, so are a bit more tollerant than the surface mount devices, which rely on the circut board for the sink. These are typically tested at 30ma, but recommended to 20ma. I drive them at 10-15A depending on the application. The lower the junction temperatore, the longer the life. In the high-output units, the mfgr is typically trying to get the most light with the fewest LED's, which means they want to drive them at the optimal light vs life point (sometimes pushing for more light than life). Since they add the control circuit, I can about break even just using discrete LED's (more of them), with resistors to deliver 20ma at 14V. In this way, a 30ma max LED can handle 21V, is still running 17ma at 12V (lowest I would ever want to take my battery bank).

Of course, if you want the good quailty of light for interior cabin applications, the new high-output style is necessary, and so would the current controller chip. Another reason mfgrs use the current control circuts is that they can produce one bulb that can work on a 12 or 24V system.

I saw all the cool displays and talked to all the engineers at the Annapolis boat show. With my EE background and 30 some years of playing with LEDs, I could see truth in some of their "pitches" but salesmanship in others. It all depends on your application, but I do agree to steer clear of the "cheap" surface mount devices, and only recommend resistor current limiting if you pick your own resistor values relative to the specific device. I have a collection of most every resistor value <= 1K for this purpose.

On bulbs with discrete LED's, (resistor limited), you can tell much by counting the bulbs and finding the lowest whole divisor (like my 21 LED unit would be 3) - this is likely how many devices they are putting in series with each resistor. Take the total current draw (ammeter), divide by the number of LEDs then mult. by the above number, and you get how much they are pushing through each LED string (therefore each LED). Anything over 20ma is usually pushing the LED pretty hard, ESPECIALLY if your test voltage is 12.4V (when engine is running, you'll run closer to 14V). If your divisor is 5 or so, theyre using rather small dropping resistors, so the device won't be very voltage tollerant. Keep in mind that using one resistor per LED wastes power, so there is an optimal.

[limmer]

does anyone know what's up with the dr. led lights from west marine? I replaced all my interior lights with these and I can tell you they are crap. I have had to return at least 6 or 7 of them. I find they do not last very long, same as mentioned above flickering and burnt out bulbs ect.. As I write this I have 2 more to return for new ones.

[forsailbyowner]

MPJA.com I installed some two years ago that were rated at 4.5 volts by simply running four in series with no resistor. They get pretty regular use in the salon,engine room,running lights and galley and haven't had any fail yet. I installed some with 330 ohm resistors also. Appreciate the tech advise I'm going to follow your example on rest as I just placed order. Mpja has some good deals. I got shunt ammeters for solar and wind for $8.95 apiece. Agu fuse block and fuses for way less than southwest windpower was asking etc...