This circuit was obtained from a 1967 General Electric manual. The circuit makes use of absolutely current components. Similar versions from other sources can be found in this section.
This circuit can operate with 5 uV to 1 mV input signals from low impedance sources such as...
This circuit was obtained from an American documentation from the 90's. The components can be...
This circuit for the automatic activation of a small lamp (or high brightness LED) was found in...