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.

Factory and Police Siren (CB18210E)
This circuit produces the sounds of the two types of siren switched by S3. The circuit is from...
Current Regulator 1.5 A L200 (CB15145E)
This circuit was found in the SGS manual of linear integrated circuits of 1982. The integrated circuit...
Operational Multi Ammeter (CB13261E)
The operational amplifier used in this circuit from a documentation from the 70s is no longer easy...