Reliability of LED flashlights?

LED is more robust to drops and have a much longer lifespan

so LED should be more reliable than Incandescent?

but how about the circuit needed for the LED? how reliable are those? doesn't hear circuitary breaking down but more parts = more complexity = more ways for possible failure?

what do you think?

There are DD ( Direct Drive ) that avoid the possible breakdown of a drive circuit. But they do fade as batteries weaken. Electrolumens has several DD lights that are robust.

I have dropped LED lights from over 5 foot and they still work.... do that to an incandescent and you have to buy a new bulb. Unless an LED light is super cheap the circuitry is well engineered against heat and drops. I once threw my UKE2AAA at the concrete sidewalk to prove to someone how rugged it is.

Lynx, i´ve dropped incans from more than 5 foot, all i can
say that the bulb MAY break, but it is likely that only the
filament gets missaranged, or the lense breaks.
it depends very much from the angle with that the ground
gets hit, the ground and the construction of the flashlight
itself.
there is more stuff thet can fail, not only the light
source. (switch, lense, batteries..)


But in general a direct drive LED light that is driven at
spec is the most rugged you can get.


and if the circuit is potted there shouldn´t brake anything.

Yes most likely the case of the light will break. I find LED lights tough enough even with the electronics in them it is the case and switches/contacts that usually fail before the electronics in them. a well made LED light should hold up as long as a well made incan does and probably outlast a few bulbs xenon modules etc.

If I was stranded on a desert island I would want an LED light instead of an incan for sure.

pyro, but even if the circuit is potted
there is mathematical a higher defect possibility
because there are hundrets of electronic devices.
each of them has a theoretical defect possibility
(Ausfallwahrscheinlichkeit in german, hope the translation is right)

You can see this in the car sector more and more defects
are electronic ones. So if you have an 1960s beatle keep
it safe, your 2001 Mercedes will not last that long /ubbthreads/images/graemlins/grinser2.gif

Cheers
Ralf

I think there is always going to be a question mark over long term reliability when you decide to purchase a LED v Incandescent.Do you trust a bulb filament to burn when you need it or do you trust in the components and build quality of potted electronic circuits?

Given that LED's are 99.9% guaranteed to work when using Direct Drive even under protracted use then the question is simply will a circuit board and it's components substantialy reduce that margin?

AFAIK the simple components and the encapsulating in epoxy of a well built circuit board provide a substantially better chance of reliability than any incandescent bulb will ever do. In addition companies like Surefire,Streamlight,Inova, etc,invest considerable amounts of money in research and development of their products and wouldn't do so if the product was inferior to existing incandescent products.

Doug

I think one aspect of reliability which is not directly related to *toughness* that LED lights have is LONGer runtime.
I consider a light reliable more when I need it and it works and works till I am finished with it. I have been left in the dark more often by incans sputtering yellow then red then forget it I am better off with a stupid candle.

I find we trust electronics more than most people think without even giving it a thought. For instance driving a new car half way across the country. Imagine how much more tremendously complex the electronics are in a car. Not just one circuit but perhaps hundreds that can go out and most often a mechanical part goes out..... instead.
Most of the cheaper less exotic LED circuits are relatively simple, way less complex than some walwarts and clock radios , tv sets and boom boxes that people use for decades at times.

[ QUOTE ]
Ralf said:
pyro, but even if the circuit is potted
there is mathematical a higher defect possibility
because there are hundrets of electronic devices.
each of them has a theoretical defect possibility
(Ausfallwahrscheinlichkeit in german, hope the translation is right)

You can see this in the car sector more and more defects
are electronic ones. So if you have an 1960s beatle keep
it safe, your 2001 Mercedes will not last that long /ubbthreads/images/graemlins/grinser2.gif

Cheers
Ralf

[/ QUOTE ]

I'm sorry, but this is simply complete and utter nonsense!

The bulb in the incandescent has a *much* higher probability of failure, both due to shock and to the limited life of the bulb itself. No contest. (Assuming all other things are built equally.) We drop (literally)electronic equipment onto other planets - it's quite possible to build something that is more impact resistant than a bulb!

1961 Beetle vs. 2001 Mercedes. I have a good friend who drove one of these, and was in an accident. The Beetle had inadequate braking, and rolled in the accident. She broke her face in about 3 places. She was lucky to have survived the accident. In a 2001 Mercedes, even if the ABS brakes, better stearing, and superior suspension and traction control hadn't helped her keep the car in control and avoid the accident, the airbag would have deployed and the car almost certainly would not have rolled. She'd likely have emerged with only minor injuries. So no, I don't buy that one either.

BTW, having had friends who owned these, and watching them try to START their Beetles on a daily basis, I really don't buy reliability in *any* sense of the word when applied to these cars.

/ubbthreads/images/graemlins/thinking.gif /ubbthreads/images/graemlins/ohgeez.gif

As a design engineer, I have heard this same "more parts = more causes of failure" BS for years. Most electronic devices do NOT fail due to random, statistically predictable failures of individual parts. They fail because of inadequate design, poor construction (bad solder joints, crappy PCB's) and/or environmental factors (impact, thermal cycling, etc.). Adding parts can substantially IMPROVE reliability by providing protection against various failure modes.
A ceramic oil lamp is substantially simpler than even a incandescent flashlight - do you think that it is a more reliable source of light? in extreme conditions? more resistant to impact?

I agree with dtenebrator, more parts can give more of a chance for a bad part to fail but really the truth is in poor design and implementation of circuits properly. If a tv set that is used sometimes 8-12 hours a day can last 15 years with all the parts in it... a similarly made LED light should be able to outlast it, due to the fact very few people use a flashlight that many hours a day.
I have had some cheap simple circuits fail on me because the manufacturer used cheap parts and poor design while fancy more complex circuits may outlast..... me.
I have a feeling well made LED lights may still be working when people put them in museums because the technology is made so obsolete people will prefer to use newer lights instead.