[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.

In engineering circles, this circuit is better known as a 7447 BCD to seven-segment decoder/driver, but just using a single chip has little pedagogical value.

How to Make Mechanical 7 Segment Display from Cardboard In today's video I want to show you 7 segment display with unique mechanism that is our own invention. There are 7 circles inside. Each ...