led cabin lights

[derekh]

Some time ago there was a post which named a company who supplied a LED cabin light. I am replacing mine at the moment and would like to find out the fors and againsts of LED lighting. My thoughts are - they use less power and last longer which is good. The light is not white which may not be so good.
Can anyone let me know where 10 lights can be purchased without the use of a marine morgage.
Thanks

Derek

<hr width=100% size=1>Work ? don't be daft , the suns out.

 

[domlee]

Dedicated LED lights are prohibitively expensive. However, a lot of traditional marine-type lights use automotive bulbs. If you were to purchase this type of light, the following site:

http://www.ultraleds.co.uk

can supply a relplacement LED bulb that has the physical characteristics of these automotive bulbs but consumes a fraction of the energy. You may find that buying a 'normal' light then replacing the bulb with an LED one would work out cheaper than purchasing 'dedicated' LED type of light.


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[Dipper]

Hella make LED cabin and exterior lights like the red one below marketed by Aqua Marine (this style is also available with white light and a variety of trims).

These retail around £20 each so not sure if this is into mortgage territory or not. One benefit is that they are waterproof so can be fitted in a cockpit.


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[silverseal]

I have recently been offered ultrawhite leds at 5volts and it would need a small resistor to step down 12 volts to 5. At 97p plus vat per LED, I am thinking of converting a couple of existing cabin lights to LEDs say 5 per fitting, which should equate in light output terms to a 5 watt festoon bulb, but only consume about 0.25 watts of power. I might also be very flash and have both red and white leds in the same fitting - switchselectable for normal or nighttime running!

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[computertech]

orlando, last july, internationaldrive, megastore outdoors boating, hunting shooting, l12 volt led strips $9 couldnt believe it. so if you want a few go website hunting in the states. outdoor world i think
stu

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[computertech]

try here http://www.basspro.com/servlet/cata...ThumbNail=yes&hvarRowCount=39&hvarStartRow=24

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[William_H]

Hello Silverseal assuming your LEDs need 50 ma then with 2 in series you will need a 40 ohm resistor for 12 volt supply however at 14 volts supply (generator on line) you will need 80 ohm resistor and then when battery is at 12 volts you will get 25 ma which is a lot dimmer light. You could use each LED with it's own resistor 180 ohms for 14V input which gives 38 ma on 12 volts not so much of a loss of light. Another plan is to use an LM317 reulator IC in a current regulator configuration where the power goes to the input and a resistor goes from the output to the LED the sense leg goes to the LED connection. The resistor is chosen to drop 1.25 volts ( between the uotput and sense legs) at the LED current ie 50 ma. So a 27 ohm resistor will do the job. This will give full brightness on the LED from over 14 volts down to about 7.5 volts battery (very flat) when using one LED however if you put 2 in series you will get full brightness down to about 12.5 volts but it will rapidly dim below 12 volts. So obviously 2 LEDs in series gives twice as much light for no more current but has problems on low voltage. You might think an easy answer would be to fit a 12 volt regulaor so the voltage to the LED and resiistor never rises over 12 volts (so you chose the resistor accordingly) however the problem is that these chips need about 2 volts more in than they can give out so you would still have no lights on 12 volts unless you used a 9 volt regulator and ran only one LED. So there is the conundrum. The best answer is to use 2.5 volt LEDs so that you can fit 3 in series. (I suspect you 5 volt one has 2 LEDs in series) NB I have assumed you are looking at 50 ma LEDs and that may not be the case in which case you will have to do the math again except if they are 100 ma LEDs you can half the resistor vlues. Are you confused PM me if I can help will

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[Graham_Wright]

E C Smith and Sons, supplier to most boat chandlers.

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[Wiggo]

You can buy a string of 10 high brightness white led lights (3 to a light), to run directly off 12V in stainless waterproof housings suitable for outdoor use, flush mounting, for the princely sum of £50 in B&Q. I have a set round the cockpit as courtesy lights, and another on the flybridge.

<hr width=100% size=1>Nihil curo de ista tua stulta superstitione.

 

[kds]

Frensch produce ones with an attractive modern style to them - unless you are determined on DIY lights. I got mine from IMP 01763 241300 at the last boat show. I am quite pleased with their Nav table light too. They have a website;
www.improducts.co.uk
I have no connections with the company, but found them helpful.
Ken

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[charles_reed]

Pros & Cons of LEDs

Very attractive until you start to research in depth.

The main advantage is the minute battery drain, about 12% of a comparable fluorescent, their comparative logevity and the colour of the light.

However LEDs require a very controlled voltage - their life is halved by a 20% overvoltage and this degradation increases geometrically.

If you sample your battery voltage over a time, you'll find the charging volts are about 13.8 on a 12-volt coventionally controlled system and 14.4 volts with a smart charger.

For this reason, allied with the costs involved, I've stuck to using fluorescent and halogen to replace conventional tungsten filament bulbs.

It's news to me that B&Q are offering LEDs - They are offering 230v and 12v halogen fittings/bulbs which could lead to a degree of confusion.

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[Wiggo]

Re: Pros & Cons of LEDs

B&Q are selling a range, some as interior lights, some as patio/deck lights. All dedicated setups, not 'bulb replacements'.

<hr width=100% size=1>Si hoc legere scis, nimium eruditionis habes.

 

[NigeCh]

Voltage or constant current ????

LED's may look like the answer .... but sofar nobody has come up with the universal circuitry.

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[Wiggo]

Re: Pros & Cons of LEDs

So running at 14.4V instead of 12 (20% over) cuts them from say 50,000 hours to 25,000, assuming you only ever use them with the engine running.

That's 24x7 for 3 years before a failure. I think it's a reasonable trade off against an 88% saving in current drain, isn't it?

<hr width=100% size=1>Si hoc legere scis, nimium eruditionis habes.

 

[bedouin]

Re: Pros & Cons of LEDs

Driving the LEDs over a range of voltages is not as complicated as it might seem.

LEDs are non-linear devices so a well selected resistor in series with the LEDs will give acceptable results over the expected range of input voltages (maybe using a Zener Diode as well). That would be fine for internal lighting but not appropriate for navigation lights as the colour balance of a "white" LED varies with voltage.

A better solution would be to use a linear regulator either as a voltage regulator or a constant current source.

Either solution would cost you a few pence from Maplins.

Even better is to feed it with a square wave, but that is getting a bit more complicated.

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