Halogen lamps failures

[spider147]

Hi all. I have an issue with the reliability of halogen lamps. At the moment I fit 28v G4 lamps to a 24v system in order to help the lamp cope with higher charging voltages and other fluctuations. I don't have the budget to fit LED or other technologies at the moment.

I am interested if others have found frequent blown lamps to be an issue, and what has been done to overcome it (if anything). Is there a particular type or make of lamp that seems to last longer.

Spider

[jfkal]

Appears to be happening if you run them on DC. I remember4 vaguely that they appear to loose more metal at one end of the filament, hence the early failure.

[spider147]

Thanks for the reply. I am interested to know if premature failure is considered an issue within the marine envirnoment, and what others have done to overcome it.

Mark

[Landlubber]

...the problem is with voltage stabilisation...they do not like fluctuations, so you need to have then powered by a more stable supply, the alternator will play havoc with them.

[jfkal]

I have changed all to LED or fluorescence types.

[spider147]

Thanks. I have done some further reading. I found something that I haven't previously considered. Apparently halogen lams do not like under voltage either. I'd assumed that because they are dimmable, a lower voltage would not matter. However this apparently messes with the "halogen cycle" and the lamp can blacken. With volt drop, I have found that the lamps could be running at only 70% power, which according to the article I read, will greatly shorten it's life (and of course output).

So, what is the recognised way to power these lamps. At the moment there is no voltage stabilisation, so the charger, alternator, voltdrop etc all play their parts. The boat in question has around 100+ 20w lamps. Can anyone recommend an economical way to achieve a stable voltage.

My client will not accept LEDs or fluorescent lamps for internal overhead lighting.

[jfkal]

Dear Spider,

you are totally right. The Halogen Cycle plays an important part as well.
Best is to run them on stable 12V AC or forget it and use other technologies such as LED's

[daiquiri]

Originally Posted by spider147

My client will not accept LEDs or fluorescent lamps for internal overhead lighting.

Did he give some particular reason for that refusal?

[spider147]

The customer trialed LED replacement lamps on his last boat and he didn't rate them. There was a problem with heat build up which resulted in the solder joints failing. As for using "proper" LED fixtures, the cost would be prohibitive, and trials on these have also shown issues with voltage stabilisation (possibly regulator problems). Again, a constant matched voltage at the fitting is what I need to achieve.

As for using 12v AC lamps, that's something I will research.

[jonr]

I agree - get a 12V AC inverter - or easier to find, a 120v AC inverter and a 12V transformer. Also use a voltmeter to check that you aren't getting a voltage drop anywhere.