🚀 go-pugleaf

In sci.electronics.design Bushy <please@reply.to.group> wrote:
>> Getting the cost down is the interesting bit.
> 
> Use a photodiode to detect the light. Can't be to hard to do, they even come
> in those 150 in 1 electronics project kits. Couple it to a small signal
> transmitter that will send a code or serial number down the power line every
> few minutes that it can't see the light. Could even be included in the
> electronics to turn on future light fittings at night.
> 
> Also, it's not restricted to one lamp type, but will work for a wide variety
> of lights. Maybe the traffic lights could be done....
> 
> Hope this helps,

The detection circuit is trivial, and inexpensive.
The power supply for it, the coupling and bypass arrangements, confirming
it doesn't do nasty EMC things and has a MTBF greatly exceeding that
of the lamp housing (say 20-50 years) and installation issues could all make 
it more expensive than a first look would make it seem.

Then you've got to look at if as you'r already putting one circuit board
into the light, connected to the mains, might it be a good idea to 
integrate an electronic ballast?

-- 
http://inquisitor.i.am/    |  mailto:inquisitor@i.am |             Ian Stirling.
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"I meant, have you ploughed the ocean waves at all?" Colon gave him a cunning
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