>
>
>On Wed, 20 May 1998, Pedro Drummond wrote:
>
>> That's it, I have to come up with a solution. On small airports, people
>> steal light bulbs from the runway. How to prevent (detect) it ? And maybe
>> detect burn-out bulbs as well ?
>>
>> Thanks in advance.
>>
>>
>> Pedro.
>>
>>
>
>

It will be near impossible to stop the "Theft", unless the bulbs are placed
in a lockable enclosure that requires a special tool to undo. But even this
may not work, as the "Would be vandal" will take this on as a challenge! If
this is the case then even special light bulbs will not do, cause then they
will be stolen for the simple "fun of it". After you have made you bulbs
"Theft proof", you may also need to make then "bullet proof", as this is
generally the vandals next option.
This is a problem, as many small airports are unmanned at night, and a
carrier detect off a radio is used to turn them on. Perhaps the simple
solution is to have so many light bulbs, that not all of them can be stolen
in one night/week.

As for detecting the possible missing bulbs, that's quite simple. Use a
circuit to measure the current/power/voltage after a given period (Let the
bulbs warm up). If different by X watts, then missing bulb/s!


Dennis


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Dennis Plunkett: Embedded Hardware, Software design
NEC Australia DRMASS
Line Interface cards
TRX software
ISDN interface card
ph 03 9264-3867

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