High Power Alarm (CB20475E)

We found this circuit in a Popular Electronics from the 90's. The circuit uses three SCRs to trigger the loads.

Infrared Optical Link (CB14674E)
In the figure we have the transmitter and the receiver for an optical audio link via infrared. The...
Common referenc dual regulator (CB8691E)
We found this symmetrical regulator in a documentation from the 70s. The circuit uses components...
Up to 1 Hour timer (CB21424E)
This circuit was found in a 1960s General Electric unijunction transistor manual. The circuit can...