7-segment display driver (CB20551E)

We found this circuit in English documentation from 1996 for PCs. The circuit is for common cathode display.

Sine to Square Converter (CB6586E)
Found in American documentation this circuit uses transistors of the time. The circuit can be made...
1 W Amplifier (CB6295E)
The TAA300 integrated circuit is not common today. In fact, the circuit shown is from a Dutch...
Rain Alarm or Door Bell (CB5369E)
This circuit was found in a 1980s documentation. Q1 and Q2 can be BC548 and SCR a TIC106. The...