Fed up of changing bulbs.

[John Orentas]

With respect, what do they do to them to make them special?

Its not that easy to go into production on a modified bulb for such small

production numbers.

 

I have now tried standard GE 12V 10W G4 capsules at over 15.5V and they are not blowing.

I just don't know if they will attain their 2000 hour rating, over voltage.

 

Mark

 

 

 

The lamps you have will be supplied as automotive type, 2,000 hours is about the longest life of that type but they certainly won't give that life if they are over-run. You can actually get them down to fifty hour life with nearly double the light output.

 

I know I keep saying this but it is sensible to wire T/H lighting with 1.0 mm or smaller cable. Most of the ones you buy are true 12 volt rating for running from a transformer.

Edited January 19, 2006 by John Orentas

[NB Willawaw]

50 Hours isn't very much. The bulbs aren't that expensive but they are a pain to keep changing as they always tend to blow at the most inconvenient moment.

 

Creating an artificial voltage drop is one way of doing it, using undersize cable, but 1mm2 cable over 60ft will impose a gradual volts drop over the length of the boat which means that the front lamps will be dimmer than the ones nearest the battery - This might not be noticeable if the bulbs can't be compared.

The only other way I can think of is to use a DC-DC converter and oversize cable to ensure a regulated 12V at both ends irrespective of what the battery voltage is. This is obviously the Gucci solution and will cost £s.

 

I will run a GE MR16 20W Halogen bulb at a constant 14.4V and see how long it lasts.

 

I know I keep saying this but it is sensible to wire T/H lighting with 1.0 mm or smaller cable. Most of the ones you buy are true 12 volt rating for running from a transformer.

Edited January 19, 2006 by NB Willawaw

[John Orentas]

I didn't explain that very well, the 50 hours is the life of another specification of lamp, used in projectors and optical instruments. For many of these things output is everything and 50 hours is a long time.

[NB Willawaw]

Yes, Cantalupi appear to have a comprehensive and attractive range of lights.

I believe the Frensch company from Germany also make something similar.

 

It would appear that they both use G4 Xenon lamps as an alternative to halogen lights and the typical quoted life for the Xenon is around 10,000 hours. However, I guess you get nothing for free in life and the Xenon lamps seem to have a much lower light output than their halogen counterparts of the same power.

Also being slightly cynical, I wonder if the Xenon lamps are also stressed by over-voltage but their longer life make them appear to last longer than a similarly over stressed halogen ?

 

Presumerably, Xenon lamps aren't so freely available as halogen ???

I have found a supplier of 10 or 20W G4 units for under £3 which isn't bad but they don't seem to be readily available.

 

I like the light fittings but I'm just sitting on the fence about Xenon lamps for the time being. I know they are supposed to run cooler, have a warmer light, be more voltage resistant and last longer but when having to commit valuable battery power I still miss the higher light output of Halogen.

 

Which Cantalupi model do you use mainly and how easy is it to replace the bulbs when they are recessed in the deckhead?

 

Mark

 

Cantalupi addressed the blowing 12v G4 capsules and now supply a "Special For Boats" so it says on the box Xenon Halogen. So far these seem far better than the original standard bulbs.

Edited January 19, 2006 by NB Willawaw

[bottle]

Hi

 

I expect you know, Cantalupi also supply a DC/DC transformer (if that is the correct description) that can be fitted to each light fitting.

 

Now as to cost and whether it would be cost effective is another thing.

Edited January 20, 2006 by bottle

[Sir Nibble]

There is a 28 v/dc standard supply in some military vehicles, some aircraft and all helicopters

That's the usual charge voltage for all 24V systems.

[Gary Peacock]

Yes, Cantalupi appear to have a comprehensive and attractive range of lights.

I believe the Frensch company from Germany also make something similar.

 

It would appear that they both use G4 Xenon lamps as an alternative to halogen lights and the typical quoted life for the Xenon is around 10,000 hours. However, I guess you get nothing for free in life and the Xenon lamps seem to have a much lower light output than their halogen counterparts of the same power.

Also being slightly cynical, I wonder if the Xenon lamps are also stressed by over-voltage but their longer life make them appear to last longer than a similarly over stressed halogen ?

 

Presumerably, Xenon lamps aren't so freely available as halogen ???

I have found a supplier of 10 or 20W G4 units for under £3 which isn't bad but they don't seem to be readily available.

 

I like the light fittings but I'm just sitting on the fence about Xenon lamps for the time being. I know they are supposed to run cooler, have a warmer light, be more voltage resistant and last longer but when having to commit valuable battery power I still miss the higher light output of Halogen.

 

Which Cantalupi model do you use mainly and how easy is it to replace the bulbs when they are recessed in the deckhead?

 

We offer customers choices from the full range and now only deal with Cantalupi for lighting. (Their products are very high quality, meet the regulations and they are reliable to deal with.

The standard light we use is the MARY

 

Mark

[NB Willawaw]

Bottle,

 

No I didn't know that and their website is not the easiest to navigate.

Did you see that on their site and if so, can I have a link please ?

 

Its probably not the right description as you can't transform DC - it has to

be chopped into AC to work through a transformer, but I know what you are getting at.

 

Thanks

 

Mark

 

Hi

 

I expect you know, Cantalupi also supply a DC/DC transformer (if that is the correct description) that can be fitted to each light fitting.

 

Now as to cost and whether it would be cost effective is another thing.

[John Orentas]

That's the usual charge voltage for all 24V systems.

 

 

Hi Snibble.

 

The 28 volts you refer to on helcopters and the like has nothing to do with a 24 volt charge rate though historically it may derive from that.

 

It is a tightly regulated and very clean supply used for many of the navigation aids and instuments on the aircraft. It is also cabable of running a 2,000+ watt searchlight along with the usual stuff. That's were I came in.

Edited January 20, 2006 by John Orentas

[bottle]

Bottle,

 

No I didn't know that and their website is not the easiest to navigate.

Did you see that on their site and if so, can I have a link please ?

 

Its probably not the right description as you can't transform DC - it has to

be chopped into AC to work through a transformer, but I know what you are getting at.

 

Thanks

 

Mark

 

 

Hi Mark

 

Yes I agree not the easiest of sites but your wish is my command

 

Link

 

 

Edit Just tried this link goes to front page, when there go to 'modular dimmers' then 'voltage stabiliser' not much info though.

Edited January 20, 2006 by bottle

[John Orentas]

Hi Mark

 

Yes I agree not the easiest of sites but your wish is my command

 

Link

Edit Just tried this link goes to front page, when there go to 'modular dimmers' then 'voltage stabiliser' not much info though.

 

 

DC to DC unit is normally referred to as a converter. You don't need stabilisation for lighting, things just aren't that critical if the voltage is very high just add a resistor to each fitting. 5p each.

[bottle]

DC to DC unit is normally referred to as a converter. You don't need stabilisation for lighting, things just aren't that critical if the voltage is very high just add a resistor to each fitting. 5p each.

 

John

 

you are probably right but as I believe it these units give out the stated voltage (12) no matter what is going in (between a stated range).

 

This has got to be better than a resistor, when the lights could running on the batteries (nominal 12) or the engine (approx 13.8 charging)

 

Agreed a resistor will reduce the voltage but will reduce it no matter what the supply, therefore the lamps (bulbs) will not be giving there full illumination at all times. Whether this would be noticeable is doubtful as our own eyes are the best regulator of light there is.

[John Orentas]

John

 

you are probably right but as I believe it these units give out the stated voltage (12) no matter what is going in (between a stated range).

 

This has got to be better than a resistor, when the lights could running on the batteries (nominal 12) or the engine (approx 13.8 charging)

 

Agreed a resistor will reduce the voltage but will reduce it no matter what the supply, therefore the lamps (bulbs) will not be giving there full illumination at all times. Whether this would be noticeable is doubtful as our own eyes are the best regulator of light there is.

 

 

Quite agree bottle, eyes combined with brains are remarkable I worked in lighting for 15 years and did many experiments in that time. You can find your way around a near dark room 0.5 lux and on a summers there is half a million lux, how many instruments could cope with that degree of variation. Experiments with searchlights showed that even a 30% change in luminance at close range could barely be detected though over 3 miles it was very apparent.

 

Back to the point, you would barely see that one volt difference even if it was changed on /off rapidly. There is a lot to be said for under running all filament lamps.

Edited January 20, 2006 by John Orentas

[bottle]

Quite agree bottle, eyes combined with brains are remarkable I worked in lighting for 15 years and did many experiments in that time. You can find your way around a near dark room 0.5 lux and on a summers there is half a million lux, how many instruments could cope with that degree of variation. Experiments with searchlights showed that even a 30% change in luminance at close range could barely be detected though over 3 miles it was very apparent.

 

Back to the point, you would barely see that one volt difference even if it was changed on /off rapidly. There is a lot to be said for under running all filament lamps.

 

Hi John

 

I agree with you on this point

 

Edit:

 

That sounds condescending it's not meant to be

Edited January 20, 2006 by bottle

[NB Willawaw]

I have had the bulb on a constant 14.4V (measured at the bulb - no voltage loss on cables) for over 55 hours. Although I haven't put a light meter on it to measure any degradation in light output over time, it looks comparable to a fresh bulb on the same voltage next to it.

It is possible that the total life of the bulb will be reduced by 30 % for every 10% over-voltage as stated before in this thread but the makers spec says it's rated at 2000 hours minimum at 12V.

At a cost of a couple of pounds each I would be prepared to live with this in exchange for a bright light in the boat rather than having a reduced output because the bulb is only getting 10 or 11V due to voltage drop.

As I said before, there is a big visible difference in brightness between this voltage and 14.4V.

 

Most boats might only run their lamps at 14.4V in very rare circumstances and for a short period of time until the batteries discharge a bit, so how long will it take to achieve that 55 hours at such a high voltage ?

 

I guess you pays your money and takes your choice.

 

 

I will run a GE MR16 20W Halogen bulb at a constant 14.4V and see how long it lasts.