LED bulbs

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capsco

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Not had much luck with the search on here, so help please, where is the place to buy LED bulbs? in my case 24v.
 
Try e bay, half the trucks i see, the drivers have changed the interior ones to led, which is great as they dont seem to go wrong, on the other hand most of them have rubbish light output!


Lynall
 
You can do what I do and build your own from scratch, or replace the internals of an existing light with LED internals, you need to be able to do a little simple maths, be able to calculate resistor values, and the worlds your oyster as far as design and build go, Its much cheaper than buying new and if the lights not right you play with it until it is.
 
Simple maths? I will be OK with the simple bit but maths a bit more of a problem.

Seriously, I would like to have ago, any tips to give me a start?






Assassin said:
You can do what I do and build your own from scratch, or replace the internals of an existing light with LED internals, you need to be able to do a little simple maths, be able to calculate resistor values, and the worlds your oyster as far as design and build go, Its much cheaper than buying new and if the lights not right you play with it until it is.
Click to expand...
 
eBay regularly features LEDs direct from the Chinese makers. Send them an enquiry for 24 volt and they will help you. I have replaced virtually all of my lighting with LEDs including 10 metres of concealed saloon in the saloon saving about 60% on my battery drain
 
Yes, you need to know the full specifications of any individual LED's you buy such as the typical and maximum forward voltage, the consumption in milliamps which is basically 1 milliamp or M/a = 1/1000th of an amp, the viewing angle which is the angle the light is emitted at, MCD which is the amount of light emitted,and series and parallel wiring. From this you can design the lighting circuit to give the light you require.

From here you will need to design and build a regulation circuit as voltage on any alternator driven power supply is variable, on a 12 volt system the voltage is nominally 12.4 volts minimum on a fully charged battery, but will rise to around 14.4 volts with the alternator running, and you need full power all the time for maximum light output, so most circuits are either regulated 12 volts or 24 volts to drive the LED's, you wire as many as you can in series to reduce power consumption, then parallel them to give light output and get a good balance between a good light output, then match the seriesed LED's to the available voltage with a resistor.

Standard voltage regulators are available for pence from electronics suppliers, and resistors are about 50p per 100, so not expensive if you get it wrong.

My last LED's were 3.6V maximum forward voltage, 20M/a or 0.020 amps current consumption, 20,000 MCD light output, and with a viewing angle of 25 degrees, cost??? 50 x 3mm LED's for £1.87p.
 
Try these people
http://www.searolf.com/page6.html
The G4s in here are rated to work between 5v and 30v
Warm white is the best IMO
However none of the LEDs that I've seen are as warm as the old Halogen ones
So, I have a mixture - those we use when on shore power and those we use at anchor.

Searolf also do an LED anchor light which works really well.

The LED plug in bulbs typically consume about 1/7th of the Halogen equivalents
 
I bought some from both http://www.searolf.com and http://www.bedazzled.uk.com/ last year.
All worked well except, as I say, LEDs don't give off such a warm light as Halogen.
I've done our galley, heads and some bedside lights and some free standing lamps - using LEDs - the rest still uses halogen.
This means that, when hooked to a shore supply, the halogens are used.
The galley and heads work better with the whiter LED lights anyway.

I've never bought any White LEDs - only warm white.
I did buy a red one to see how well it works as a night light - worked OK - seems to keep the glare down a bit on night passages.

Sorry, I couldn't remember the name of http://www.bedazzled.uk.com/ earlier.
 
Most have a voltage regulator to give a stable output voltage and then a resistor to match the seriesed LED's to the output voltage, hence the reason many are rated as 12-30 volts input as most common (and cheap) regulators working range is 12-30 volts.
 
What happened, it posted before I finished.

Above: this is where the LED lights are called 12/24 volt rated or suitable for both voltages or multi voltage.

Yes you can get 12 volt and 24 volt rated LED lights as many are either rated for a 12 volt input or a 24 volt input, particularly in the vehicle market as many are cheap and don't contain any form of voltage regulation, just a resistor to match the seriesed LED's to the maximum supply voltage which is usually 14.4 volts for a 12 volt LED bulb as this is the maximum voltage which can be delivered to the light if the alternator is working at maximum voltage; when the engine is switched off and the battery supplies around 12-4 volts having an unregulated voltage means the voltage drops at the battery and the light output at the light drops in relation to the voltage.
 
Assassin said:
What happened, it posted before I finished.

Above: this is where the LED lights are called 12/24 volt rated or suitable for both voltages or multi voltage.

Yes you can get 12 volt and 24 volt rated LED lights as many are either rated for a 12 volt input or a 24 volt input, particularly in the vehicle market as many are cheap and don't contain any form of voltage regulation, just a resistor to match the seriesed LED's to the maximum supply voltage which is usually 14.4 volts for a 12 volt LED bulb as this is the maximum voltage which can be delivered to the light if the alternator is working at maximum voltage; when the engine is switched off and the battery supplies around 12-4 volts having an unregulated voltage means the voltage drops at the battery and the light output at the light drops in relation to the voltage.
Click to expand...

A boat requires constant-current controlled LED lamps, often advertised as being suitable for 10-30v, therefore are suitable for use on both 12 and 24v systems. These lamps will output exactly the same level of light at 10v as they would at 30v because electronics built into the lamp control the current to the optimum level for the specified light output.

In contrast lamps designed for use in motor vehicles are designed for a single voltage such as 12 or 24v. This type of lamp will be damaged if they are exposed to a higher voltage. This is an important point as boats differ from vehicles due to the use of deep discharge house batteries. Most modern boats and increasingly older boats utilise smart battery chargers which when operating in equalisation mode will apply, for instance, up to 16v to a 12v deep discharge battery. This voltage will result in a doubling of the current flowing through a lamp designed for 12v. The same principle applies to 24v systems. The consequence is predictable, at best a reduced LED service life at worst a risk of fire. Vehicle lamps are cheap for a reason, they are unsophisticated and rely solely on simple SMD resistors to control the current. Vary the voltage and the current will vary as will the light output.

Regards
 
Which is the sole reason I regulate the voltage locally to the circuits, much the same happens when the alternator is charging as I have previously mentioned.

You don't need a constant current driver, its just another way of achieving the same result.

My dislike of replacement bulbs is that they suffer the same foibles as ordinary bulbs, they require a good contact in a holder and they can move in heavy swells which can disrupt that contact or corrode, hence making my own and wiring them in directly. My other preference is the directional light they offer, you can aim light where you want or need it, you don't have half the buld bouncing off reflectors and providing ueless light.
 
Assassin said:
Which is the sole reason I regulate the voltage locally to the circuits, much the same happens when the alternator is charging as I have previously mentioned.

You don't need a constant current driver, its just another way of achieving the same result.

My dislike of replacement bulbs is that they suffer the same foibles as ordinary bulbs, they require a good contact in a holder and they can move in heavy swells which can disrupt that contact or corrode, hence making my own and wiring them in directly. My other preference is the directional light they offer, you can aim light where you want or need it, you don't have half the buld bouncing off reflectors and providing ueless light.
Click to expand...

You make a good point about lamp contact corrosion, this is very common on many boats, due to minor electrolysis between different contact metals and salt laden air. Using a good contact grease is extremely effective at preventing corrosion and improving electrical contact. The best product I know of is Contralube 770, it's widely available and relatively inexpensive. I think one tube should be kept on all boats and used on all metal to metal and battery connections. It's ideal for both power and radio connections and won't introduce any additional impedance. One tube would last years on most boats.

Regards

Adrian Jones
 
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