Light sensitive curtain control module required

["David Chapman" <david@xxxxxxxxxx>]

I've been using the Add-A-Motor curtain control kit for a few months, these
cost about 50 quid direct from the States and work OK controlled by a
timeswitch but ideally I'd like them to be light controlled. Don't want to
go as far as X10. They need a pulse for about a minute (can be left on
longer) to transition between open and closed. Could be mains but prefer 12
volt. Ideal would be something that at say 25% light (adjustable) closes a
relay for 5 minutes. The difficult part is I'd like it to this on both
gradients - in the morning as it goes from 0 to 100% light and in the
evening as it does the reverse.

Any ideas ?

David C

ps the Add-A-Motor is available here http://www.worthdist.com/aam/aam80.htm