Propeller clock

From HvWiki

"Propeller Clock" Mechanically Scanned LED Clock by Bob Blick is the first one (as far as I know).

Also known as "persistence of vision" displays.

Or, on the 4HV discussion forum, a LED Spinner or a LED spinner thingy.

The vast majority of propeller clocks use 5, 7, or 8 LEDs (easy to interface to 8 bit output ports; minimum 5 LEDs to make numbers like "5" and "8" distinguishable). But one 4HV thread discusses the Nixie Propeller Clock.

Description:

A Propeller Clock utilizes a mechanically scanned display usually consisting of a row of LEDs. In the scanned display the LEDs are not illuminated constantly. The LEDs turn on and off at precise intervals, one after another, extremely rapidly while being rotated at several thousand RPM. Due to the slow response of the human eye an effect known as Persistence of Vision gives the illusion of a static stable display. There are 2 main types of rotating displays, cylindrical and disk shaped. Whereas cylindrical displays are only capable of displaying text and digits disk shaped displays have the ability to display analog clock hands.

An Example of a running Propeller Clock