Found in a1967 Ferranti documentation, this circuit uses an operational amplifier from that time. The circuit uses a LDR as a sensor and has a null setting.
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...