LED Cabin Lights

[jcherubini]

It's a shame that Gord does 'NOT' know...

... much about LED technology... otherwise he could have confused us even more with that technospeak!

 

[jcherubini]

It's a shame that Gord does 'NOT' know...

... much about LED technology... otherwise he could have confused us even more with that technospeak!

 

[Wanderer138]

Hey Henk

Glad to see you're still around. One possible cause of the short LED life that you didn't mention is corrosion at solder joints or other electrical connections due to the damp, salt air. PeterH23 "Raven"

 

[Wanderer138]

Hey Henk

Glad to see you're still around. One possible cause of the short LED life that you didn't mention is corrosion at solder joints or other electrical connections due to the damp, salt air. PeterH23 "Raven"

 

[Gord May]

sorry

With apologies to J Cherubini II Actually ( conventional) lamp life is NOT rated according to “MTBF” (Mean Time Between Failures) - which would indicate that, for a 2,000 hour rated lamp, one failed during every 2,000 hours of testing. Specifically, MTBF is the reciprocal of the sum of the failure rates of the components of the system (with the failure rates being expressed in failures per hour), or average time between failures. (BTW: I know there is a difference between “Mean” and “Average”)For the conventional lighting industry, the average life of a particular lamp type is the point at which 50% of the lamps in a representative group have burned out. A VERY different statistic !The definition of “life expectancy” varies from industry to industry. The useful life for a LED is generally defined as the calculated time for the light level to decline to 50% of its original value. For a number of reasons, this is not a totally acceptable rational.See the IES article: (note: “IES” = Illumination Engineering Society)“IES Paper #52 What is Useful Life for White Light LEDs?”http://www.lrc.rpi.edu/resources/pdf/NN_ies1.pdfThe life of an LED depends on its packaging configuration, drive current, and operating environment (primarily Temperature). A high ambient temperature greatly shortens an LED's life. LEDs are current-driven devices, not voltage driven. Although drive current and light output are directly related, exceeding the maximum current rating will produce excessive heat within the LED chip due to excessive power dissipation. The result will be reduced light output and reduced operating life.To ensure LED longevity and reliability, heat dissipation and other degradation factors should be considered in the design of LED products. For operation at any given voltage, manufacturers build-in a current limiting resistor, a full-bridge rectifier, a protection diode, or other circuitry to protect the LED.Static electricity and surge damage LEDs. It is recommended to use a wrist band or anti-electrostatic glove when handling the LEDs. All devices, equipment and machinery must be electrically grounded.Solder the LEDs no closer than 3mm from the base of the epoxy resin. For solder dipping, it may be necessary to fix the LEDs for correct positioning. When doing this, any mechanical stress to the LEDs must be avoided. When soldering, do not apply any mechanical force to the leadframe while heating. Repositioning after soldering must be avoided. Recommended Soldering conditions for LED Lamps: Soldering Iron - 300degC(max), 3sec(max) Dip Soldering - 260degC(max), 5sec(max)Henk:Deep Creek promises “Text to come about types of drivers and power supplies for LED devices.”http://www.deepcreekdesign.com/ledgeek.htm

 

[henkmeuzelaar]

Sorry 2

Gord, thanks for the information about Deep Creek's "text to come". I hope they don't wait till all the LEDs in their wonderful US $ 300 tricolor mastlights have died.With regard to the instructions on how to solder individual LEDs in a cluster; when the clusters were still more expensive it did indeed occur to me to cut the whole thing open with a Dremel and try to resolder the failing elements. Even then, however, I figured my own time was more valuable than that. Now that the price has come down I can only hope that the boys & girls in China who are soldering all this together are indeed reading your instructions.....With regard to the underlying statistics: in case of a Gaussian (or any other symmetric distribution) the mean, the average and the "point where 50 % has failed" are one and the same. Do you have any information to suggest that the statistical distributions around the mean for LED failure time are markedly asymmetric??Fair winds Flying Dutchman

 

[Fred Ficarra]

Henk and Gord you guys are

proof-positive of the wonder of the English Language. I read every word you guys write. Thanks so much and happy Holidays. (but Mathematics is even more of a wonder, like string theory. I'll bet Gord has written a paper on it. )

 

[henkmeuzelaar]

You do know how to make someone feel GOOD, Fred

And, yes, you definitely are the life of the party on this board. So, "Vrolijke Kerst en Gelukkig Nieuwjaar" to you and all other partygangers lost in cyberspace!!Flying DutchmanPS: It is good to know that someone actually reads what I write. I should probably try to do that myself someday; preferably BEFORE posting it....

 

[henkmeuzelaar]

Peter, I agree corrosion could be important

If so, we may all be in trouble since it might be awhile before marine-quality LEDs will become available. Even then, the stickershock is likely to exceed 12 Volt.On the other hand, most landlubbergrade laptop computers hold up quite well at sea in spite of a similar mix of ingredients at work.Flying DutchmanPS: Come to think of it; the combined effects of salt water and electrical current might produce nothing short of a micro-Electrosan! Just imagine the benefits of a battery-powered, wearable unit working 24/7 where the light never used to shine.... FD

 

[Patrick Hannigan]

I went with fluorescent

Hello,I recently replaced the old galley lights in my 1969 Columbia 36. I considered putting in LED lights, but went with compact fluorescent instead. I put in two Alpenglow lights. It came down to efficiency. This sentence from Alpenglow's site sums it up: "The currently available  white LEDs produce about 30 lumens per watt which is double that of incandescent bulbs, but compact fluorescent tubes produce 65 lumens per watt."The bulbs are supposed to last between 5,000 and 10,000 hours. When one fails, I change it. What do you do about the failure of one of the 30 to 50 LEDs that you've got hooked up to provide about the same light? Do I desolder the burned out one, and solder in the new, or wait till enough go out that I can barely see? How many have to go out before you toss the whole assembly and start over? My Alpenglow lights do use LEDs though, but only in RED mode. These lights use compact fluorescent to produce white, and LEDs to produce RED. Sorry to sound like a commercial or something, but these lights work great and are also beautiful. Think twice before switching to LED for cabin lighting. Consider compact fluorescent first. That goes for halogen and cold cathode, too.Nav lights are a different story, of course.Patrick

 

[Patrick Hannigan]

I went with fluorescent

Hello,I recently replaced the old galley lights in my 1969 Columbia 36. I considered putting in LED lights, but went with compact fluorescent instead. I put in two Alpenglow lights. It came down to efficiency. This sentence from Alpenglow's site sums it up: "The currently available  white LEDs produce about 30 lumens per watt which is double that of incandescent bulbs, but compact fluorescent tubes produce 65 lumens per watt."The bulbs are supposed to last between 5,000 and 10,000 hours. When one fails, I change it. What do you do about the failure of one of the 30 to 50 LEDs that you've got hooked up to provide about the same light? Do I desolder the burned out one, and solder in the new, or wait till enough go out that I can barely see? How many have to go out before you toss the whole assembly and start over? My Alpenglow lights do use LEDs though, but only in RED mode. These lights use compact fluorescent to produce white, and LEDs to produce RED. Sorry to sound like a commercial or something, but these lights work great and are also beautiful. Think twice before switching to LED for cabin lighting. Consider compact fluorescent first. That goes for halogen and cold cathode, too.Nav lights are a different story, of course.Patrick

 

[Last Mango]

Spec's for a specific LED

Here's spec sheet data for a specific LED: High Luminous, reliability, long life: part no. BT-985bsk-31-f-a6, if this helps, and a short note on conversion-- if you want to make your own to fit current fixture. MFG: GEI Inc. White LED Forward Current- 30ma, lumen 3000, viewing angle 2 deg +- 1/2, power dissipation 150 mW, operating life 1k hours. LED characteristic curves almost linear in forward current & voltages, ambient temperature ratings.Conversion:As a rule, 20ma requires a 560 ohm resistor, but consider measuring the amperage to adjust. I used a 2 watt resistor with 4 LED's yields less temp problems in current reduction. At 5 LED’s, some heat factor noticeable. The higher the current (less resistance) the shorter the life. As a rule, I used about 28 LED’s for a 10 watt bulb. But, since the LED was very directional, more LED’s might be needed to accomplish the task and the orientation of the array could be changed. The LED lighting takes some getting used to because of the different temperature of the light output, but one might add an amber LED to the mix if necessary.Cautions: LED’s are static, current, soldering heat and bending-lead sensitive. Care must be taken in each area to avoid damage.Overall cost: ~ $10 - $20 per light fixture depending on your luck finding a discount.I hope this helps, Happy New YearLast MangoPS: No, I'm not a salesperson.

 

[Jung]

LED current .

Ultra bright LED has a forward voltage drop of 3.3-3.5V, you don't need any current limit resisitor. Just connect 4(brighter) or 5(longer service life) in serious and you can use boat's 12V system to power LED cluster directly. Parallel connect as many clusters as needed for more lightYou can find specification of LEDs from many LED suppliers web site.

 

[william3045]

monitoring dc A consumption cheaply

having a small boat and only 160 A/H available energy consumption/monitering is a real concern for me too. i'll admit tho, i think i'd be looking into candles before LED's...especially since i think i am about to name my boat "Simplicity". what is the cheapest way to monitor amperage consumption? (hope this isn't real far off the topic). should it not be possible to use a digital VOM inline w/ the batt bank to see what the current draw is as various devices are switched on or off?william

 

[Paul]

Candle

I had gimballed oil lamps on my old boat a 25 Northern and really liked them but they didn't provide enough light to read. I'm still thinking of installing them on my new 35 O'Day as well as the replacing the halogen bulbs with LEDs. I think using candle would be too dangerous on a boat.I don't think a normal VOM could handle the amperage drawn unless you only put it in series with the batteries while you turned on one circuit at a time. Most VOMs only have a 10 AMP maximum and then only for a few sseconds. The battery monitors like the LINK 10 put a very small resistor called a shunt that can stand very high amperage (> 400 AMPs) in series with the negative ground of the batteries. Then the monitor measures the voltage drop across the resistor to determine how many AMPs are being used. Guess if you can find a shunt like this and know its resistance you could do the same by measuing the voltage and use OHMs law I = E/R where I is the amps and E is the voltage measured and R is the resistance. The voltage might be quite low so you'd need a very good VOM. Better to buy a battery monitor.

 

[william3045]

monitoring current draw

candles are only a figure of speach....kinda. actually i do have 2 gimbled kerosene lamps for ambiance mostly. even kerosene in the cabin is dangerous tho, as are allot of things on a boat....propane, alcohol, gas, etc. however, there are gasses i deal with at work that require me to be in scba gear to work with so i'm no stranger to being careful!my craftsman pro digital will handle 20A but you're right...i wouldn't want to do it for long. guess if i was being a real tight-wad i could find a shunt, measure the resistance carefully, and do as you say. on the same note i guess it would be feasable to measure V drop to ground and calculate I knowing batt V with no load and measure batt V with the load. (probably not terribly accurate)all that said, who deals the link system and about how much would a simple set-up be? i have seen very complex systems but it seems that a dedicated A meter and shunt should be about all one would really need.thanks~william

 

[Gord May]

Ammeters

Meters from Blue Sea Systems:http://www.bluesea.com/dept.asp?d_id=7461&l1=7461Analog Meter Instructions: http://resources.myeporia.com/company_57/9322.pdfDigital Meter Instructions: http://resources.myeporia.com/company_57/8732.pdfMore on Wiring Digital Meters: http://www.bluesea.com/Article_detail.asp?Section_ID=137&id=84Switching Inputs to Digital Meters:Part 1: http://www.bluesea.com/Article_detail.asp?Section_ID=137&id=87Part 2: http://www.bluesea.com/Article_detail.asp?Section_ID=137&id=88Retail Price List (‘05): https://resources.myeporia.com/company_57/2005_Retail_Price_Schedule.pdf