Split Flap Displays

That’s cunning

I don’t think they always used a stepper though because they came in only about 40 years ago, and AFAIK split displays are much older.

Don’t tell Bendix King about this. They might incorporate it in their latest attempt to emulate a KI256

I always LOVED these things! Much better than the – usually far too small – monitors that replaced them. @Peter: the patent was filed (in the US) in 1966 and can be found here

On a quick read, no mention is made of a stepper motor, indeed. The patent uses a DC motor and a sort of gray-code encoder to control the power to it, by the looks of it.

Whether using a stepper would get around the patent (which has long expired anyway) I can’t tell; not being a patent lawyer

I’m a little disappointed. From the thread title I was hoping to finally get an indicator that would tell me when to replace the flaps ;)

I’m a bit disappointed. I thought it was going to be an aerobatic display using asymmetric flaps!

There’s still a few mechanical things like this around – occasionally you’ll find a Network SouthEast “clicker clock” at train stations around the south east of England – these are mechanical 7-segment displays that have rotating parts to “turn on” segments, and they click as the segments turn (the more segments that turn at once, the more they clatter).

I want one. Perhaps a clock instead of a text display.

I have been looking for a ‘Public Transport’ type clock (or digital display with a nice font) for ages now. Despite living in London they are harder to find than you might think.

Ohoh, what will my wife say with the clicking… perhaps it will have to go in the garage/workshop.

This is a split flap Apparently they were invented by Orville Wright in 1920 Link