> I would strongly suggest that you look at something like the Ferranti-Pac= kard > Flip Discs as used in outdoor signs. They are a simple electromagnet tha= t > operates a bistable disc - black on one side, florescent yellow on the ot= her. > >=20 > We used to make vehicle-mounted traffic signs that used these displays - > awesome visibility except at night. The florescent lighting available ba= ck then > just sucked big-time. >=20 > I think that we still have a bunch of the larger panels hanging around in= the > back storage. I'll look and see how easy it is to remove a single disc a= ssembly. >=20 > FWIW - I think that the disc is about 1.5" diameter. I don't know at wha= t > distance a single disc would be visible. I do know that a full panel (18= " tall, 5 x > 7 array) is visible from many hundreds of feet away. Those are the ones I was thinking of, the equipment we had used a 1/2" disc= .. --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .