Fast adder 1 (CB7055E)

We found this circuit in an Electronic Engineering from the 90s. It applies to any logical family.

HFE meter with LED Indicator (CB17001E)
This circuit was found in a 1995 documentation and is very simple to assemble, as the components are...
Headphone Amplifier (CB4386E)
Found in a 1964 magazine, this is a small headphone amplifier from 500 ohms to 10 k ohms (magnetic...
Control unit CIR11045S CB20368E (CB20368E)
This circuit was found in a 70's American schematic. It can be used for several purposes such as...