Found in a 1980s American documentation, this circuit has a current consumption of only 1 mA. The crystal can be from 100 kHz up to a few megahertz.
The idea of this circuit from a 1960 publication is simple: we can switch the transistor being...
Using a small speaker as a microphone, this 10-LED circuit was found in the March 1992 issue of...
We found this circuit in a 1977 documentation. The National Semiconductor's LM380 is no longer...