Found in American documentation from the 1980s, this circuit has a diode feedback. At the exit we have an indicator LED. The LM3900 is a transconductance operational amplifier.
The circuit presented was obtained in the 1994 Linear Applications Handbook from National...
This circuit, suggested by National Semiconductor, provides an output voltage proportional to the...
This circuit is from a cookbook to timers. The circuit is triggered by an external signal and,...