Bilateral current source 2 (CB20819E)

We found this circuit in an American publication from the 1980s. Equivalent modern operational amplifiers can be used.

Two conventional 78xx power supplies (CB25958E)
This circuit appeared in the June 1990 issue of Radio Electronics magazine. Integrated circuits must...
SCR Photosensor (CB16109E)
Lockout shooting, due to the incidence of light, can be achieved with the circuit in the figure. In...
Galena with FET Preamplifier (CB10212E)
This circuit can function either as a crystal or galena receiver with a pre-amplifier using a FET...