In essence, he engineered a physical decimal to 7 segment decoder, much like the electronic one inside the SN74LS47. The whole assembly is capped by a knob that indicates which digit is currently ...

In essence, he engineered a physical decimal to 7 segment decoder, much like the electronic one inside the SN74LS47. The whole assembly is capped by a knob that indicates which digit is currently ...

Usually, almost all 7-segment decoder ICs have a blanking input (RBI) connection to imply this type of brightness control. Because, the frequency in picture is above 50 Hz, unwanted flickering effect ...