What is or are, the most likely and common ways – the weak links in the chain (including I assume poor electricity wiring / configured housing) – that cause a traditional incandescent light bulb to blow?
And how much does manufacturing / materials quality of the bulb make a difference in any of those factors? (In other words, should an expensively, state-of-the-art constructed bulb in terms of materials purity and construction robustness, generally last a lot longer than the average bulb on the market?)
I understand it is a fairly simple lighting technology, so what complications cause them to not last longer than they generally do? Is 'blowing' the only way that an incandescent can ever expire?
Best Answer
Most light bulbs have a number of service hours designed in. This is achieved fairly accurately and on purpose during manufacturing. Consumer grade light bulbs burn out faster and the awful truth is that in that way the manufacturer ensures it can keep producing the light bulbs and make money. The main cause is the tungsten filament slowly evaporating until it gets too thin to carry the current. The trick during manufacturing is to etch the filament to a carefully designed thickness so the lifetime is
reducedprogrammed.The origins of programmed life light bulbs began with the Phoebus Cartel in 1924.
There are also light bulbs with a special stronger filament (basically they skip the 'etch-cycle'), these are for use in high reliable applications and last longer. They are commonly used in places that are hard to reach and are more expensive. Not sure about the proper name of these light bulbs. Because of the extended life time these bulbs are more expensive as a manufacturer has only limited room for producing spares. (What need is there for spares if the bulb doesn't fail?)
Where Australia and EU banned the consumer grade bulbs, the strengthened filament is not banned because of its specialized application. The latter type is just not available in your regular shop around the corner.