Found in a Popular Electronics from the 1990s, this circuit is a 1-digit counter that advances under the command of S2. The circuit can be expanded to more digits.
Found in American documentation this circuit uses transistors of the time. The circuit can be made...
The TAA300 integrated circuit is not common today. In fact, the circuit shown is from a Dutch...
This circuit was found in a 1980s documentation. Q1 and Q2 can be BC548 and SCR a TIC106. The...