This circuit was found in a 1970s General Electric documentation. This circuit already used an emitting LED. The circuit operates at frequencies from 50 Hz to 50 kHz with short pulses
We found this configuration in the Linear Applications Handbook of the National Semiconductor of...
This circuit is an application for an operational amplifier with field effect transistors from...
This circuit was found in an old Radio Electronics, but can still be assembled as the components are...