On Sat, 17 Jun 2006 21:06:35 +0100, Steve Firth
wrote:

|On Sat, 17 Jun 2006 14:32:24 +0100, Dave Fawthrop wrote:
|
| On Sat, 17 Jun 2006 14:02:46 +0100, Steve Firth
| wrote:
|
||I would suggest that you start with a solar panel, and then add a wind
||gneerator if necessary. However I also work on eletrical/electronic
||installations on motorways and if you look you will see that for low
||current drain stuff we use solar only, for higher drain uses we have both
||wind and solar.
|
| What are those green boxes which you see beside motorways, with a solar
| panel on the top?
|
|They are traffic counting devices. The box is linked to a set of loops
|buried in the road surface one pair of loops in each lane. You can usually
|see the loops as a shiny outline on the road surface. The green box counts
|traffic flow and sends the data back to the National Traffic Control
|Centre. NTCC use the data to work out where there are serious delays and
|then set messages on the EMS signs to divert traffic around the problem.

Thanks!
--
Dave Fawthrop dave hyphenologist co uk Google Groups is IME the *worst*
method of accessing usenet. GG subscribers would be well advised get a
newsreader, say Agent, and a newsserver, say news.individual.net. These
will allow them: to see only *new* posts, a killfile, and other goodies.