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LED Lighting

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I'm a new member on this forum and would like to offer to try to answer any questions members may have in respect of LED lighting issues associated with Marine vessels. I regularly contribute to technical threads on the YBW forums.

Let me say at the outset that I am the Technical Director of Boatlamps Ltd, however I do only offer general advice and am very careful not do not push any of my company's products on boating Forums. For example I always stress that boat owners should compare products offered by different suppliers and make up their own mind exactly which products match their needs and pocket. If they are well informed in respect of the options then selecting suitable products is so much easier.

There are many sources of LED lighting products available to boat owning consumers and much confusion and mis-information abounds. One issue often on forums is the fact that there is a big price differential between what appear to be similar looking LED lamps. How can a lamp that externally looks the same be offered for sale for a quid when other companies are selling what looks to be the same lamp for £7.50. Are people being ripped off? Are the lamps the same? Why not always go for the cheapest lamps? All very good questions. If members are interested I will be pleased to answer these questions and any others members may have.

Regards

Adrian Jones

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Hi, and welcome to the forum, any info is always welcome , we have started to use led street/yard lighting and can vouch about the difference in led ,s,for example we have put flood lights up with 1 led lamp fitted that gives off the same amount of light as a 250w son t sodium....you don,t want to look directly at one of these!! :wave

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Hi, and welcome to the forum, any info is always welcome , we have started to use led street/yard lighting and can vouch about the difference in led ,s,for example we have put flood lights up with 1 led lamp fitted that gives off the same amount of light as a 250w son t sodium....you don,t want to look directly at one of these!! :wave

Are they the same as the ones on your Dive Deck Trevor? ;)

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Welcome, always useful to have good information from a qualified source, I will start off with a question. Is a good base to start from to search for lamps that are multi voltage, e.g. 8v - 36v as an indicator of suitability in a marine, that is to say, variable voltage environment and if so what is the science / rationalle behind that, if not then why?

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Welcome, always useful to have good information from a qualified source, I will start off with a question. Is a good base to start from to search for lamps that are multi voltage, e.g. 8v - 36v as an indicator of suitability in a marine, that is to say, variable voltage environment and if so what is the science / rationalle behind that, if not then why?

A good question to start with.

As I mentioned in my introduction one LED lamp can look very similar to another with sometimes the only obvious difference in an advertisement is price. Looking on this and other forums I have seen that some boat owners have purchased very low cost lamps from Ebay and mostly seem satisfied with their purchases. After all 10 lamps for £15 must be a bargain in any terms why pay upwards of a fiver for a single lamp.

Lets see if we can make sense of what the differences are.

LED lamps are current operated devices, the light output is directly related to the actual current flowing through the LED and this current has to be limited to safe levels or the LED will overheat and its working life will be very much reduced. LED lamps designed to work on a fixed voltage have their operating current controlled by a simple resistor. These type of lamps are often sold cheaply on Ebay and are mostly used on motor vehicles for interior and signal lighting where if output differs it wouldn't be particularly noticeable. The downside of resistor controlled lamps is that light output will vary with voltage, drop below the designed working voltage and the lamp will dim, go above the ideal voltage and damage will occur. LED damage due to small increases in voltage is cumulative and will often result in a greatly reduced service life. For larger increases in supply voltage the working current will increase exponentially and the lamp will catastrophically fail. So to summarise, a resistor controlled lamp is designed to give its optimum light when a fixed constant current flows through the LED. Increase the voltage and the lamp will be damaged, at best this will result in a very much reduced service life, at worst I have seen solder melt! The fact is a boat owner will not know what resistors are installed therefore any purchase is in fact a gamble.

Unfortunately a fixed voltage on our boats is not very common, voltage will vary dependant on whether power is being supplied by the boats battery, its engine powered generator or a charger connected to shore power supply. Using a 12V system as an example, when the engine powered alternator is charging the battery the boats voltage will rise to around 13.8V. Modern mains powered battery chargers are increasingly using de-sulphating or equalising cycles which can further increase the supply voltage to around 16V. In tests I have carried out in my lab a lamp designed for 12V when connected to 13.8V consumed 50% more than its design current and at 16V it reaches 200%, or double its designed working current. The implications are obvious.

A second type of LED lamp is available which looks similar but differs very significantly due to on board electronics. These lamps are rated to be used on any voltage between 10-30V which makes them ideal for use on our boats. The electronics are designed to provide a constant-current through the LED lamp, independent of any variations in the supply voltage. This means that the lamp will always have exactly the right design current consequently it will have the same light output at 10V as it will at 30V and its working life will be maximised.

In summary a well designed constant-current controller results in very much improved lamp life, obviates overheating whilst maintaining a steady bright light output. You can expect to pay from a fiver upwards for a constant-current LED lamp with price dependent on the declared Lumen Output of the lamp.

Any questions I will try to answer.

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I pay up to nearly £20 per light for IP65, (bit less for ip40 )

but thats 'cos they throw the light in the right direction and distance and

mainly i think they look nice :dance

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