Hello John,
I too enjoyed reading about the "Solar Powered Sundial". Alas, as you
suspected, someone has already thought of it. In fact the article, that
I read when I was a teenager, was what got me interested in electronics
AND sundials both. The article "Build a Solar Powered Sundial" appeared
in Popular Electronics and used the output of two photo detectors to
drive a small DC motor via an H-Bridge until the detectors output became
"balanced". The unit also had solar cells to recharge the onboard
NiCads. Although the electronics were sound the sundial portion was not
so hot (although it did look pretty), they used equal angular lines as
the hour marks and butchered the explanation of the EoT. Still, it was a
lot of fun to build and it even worked when it was foggy (the detectors
had good IR sensitivity), which happens quite a bit where I live i.e.,
"sunny" California!
-Luke
John Pickard wrote:
>
> Ruud,
>
> Wonderful stuff! Many thanks for making the translations available.
>
> I love the motorised dial. Elegant concept, how come no one thought
> of it before? The photo makes it look a bit clumsy, but as a
> prototype who cares? I imagine that a manufacturer could apply a bit
> of elegant design and packaging and come up with a rather attractive
> gift.
>
> Parenthetically (and with my tongue very firmly in my cheek!): Could
> also be made in a military version (i.e. camoflague colours, and
> waterproof to 1000 m where I am sure it would be terribly useful!) as
> part of the survival kit of pilots. Sure would be better than the old
> tables! And more reliable than trying to find "I love John" carved
> into trees!
>
> Anyway, I think it is a wonderful design and may I ask if it is being
> packaged commercially. Definitely the universal dial as a gift for
> any gnomist anywhere!
>
> John
>
> Dr John Pickard
> Senior Lecturer, Environmental Planning
> Graduate School of the Environment
> Macquarie University, NSW 2109 Australia
> Phone + 61 2 9850 7981 (work)
> + 61 2 9482 8647 (home)
> Fax + 61 2 9850 7972 (work)
