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Author Topic: Why do low energy lightbulbs take so long to reach full brightness?  (Read 2115 times)

Offline thedoc

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Oliver Clark  asked the Naked Scientists:
   Hi Chris,

(Great Show)

Why do energy saving lightbulbs take so long to get to a bright light and why is this level still dimmer?

Oliver Clark (Aged 12)

What do you think?
« Last Edit: 01/04/2012 12:50:01 by _system »


Offline Soul Surfer

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Presumably you mean the ones based on small fluorescent tubes wrapped up.  There are two reasons for this.  Firstly the tubes depend on mercury vapour to run properly and need to warm up a bit to work properly.  Secondly to avoid excessive stress on the electronic driver circuits.  While the tubes are warming up they tend to need a bit of extra power to get them going.  with non electronic tubes this is easy and they warm up much quicker but with the electronic circuits you would need much more robust bulky and expensive components to allow for this quick warmup and they would be under utilised for the main part of the life of the bulb so it is a balance between reliability and warmup speed and the compact tubes compromise by having a slowish warmup of a minute or two.

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