This LED flasher was described in the Radio Electronics Experimenter magazine special issue of 1989. It was designed to be assembled with SMD components.
This circuit was found in a 2005 Linear Technology documentation. The circuit is based on LTC4213...
This wired intercom was found in a 1960 Sylvania transistor manual. The transformers are the type...
We found this circuit in a Japanese publication from the 1960s. The frequency depends on the coil,...