The configuration shown was found in an old Poptronics but can be easily assembled using a common calculator photocell. The relay is according to the supply voltage.
This circuit appeared in the June 1990 issue of Radio Electronics magazine. Integrated circuits must...
Lockout shooting, due to the incidence of light, can be achieved with the circuit in the figure. In...
This circuit can function either as a crystal or galena receiver with a pre-amplifier using a FET...