[Fran] demonstrates the display running with a CD4511B BCD-to-7-segment decoder, hooked up with a bunch of 3904 power transistors to get the chip working with filament bulbs instead of LEDs.

The arms then cause the elements to flip as they count up through the digits. In essence, he engineered a physical decimal to 7 segment decoder, much like the electronic one inside the SN74LS47.

This display driver circuit shows how a Seven Segment Display is driving with the help of the 5 stage Johnson decade counter IC CD4033.The IC has counter and decoder in one package. It converts the ...