Based on the well-known LM3909, this LED pulser circuit was found in American documentation from the 90's. The power supply is only 1.5 V.
We found this circuit in an old documentation from the 70s. The sensor is an LDR that must be...
This circuit with junction field effect transistors was found in documentation from the 1980s. The...
Common general purpose silicon diodes when direct biased provide a voltage fall of about 0.6 to...