By combining 49 of them he’s put together a soda bicarb diode steering circuit for a 7-segment display capable of showing the digits 0 to 9.

Many options exist to drive seven-segment LED displays, but most are limited to low output currents. The approach described here uses one 74ALS374 or 74AS374 octal latch, wired as a shift register ...

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. Building a simple circuit with 39 ...