Based on the TCA6600 or TCA5500 this circuit was found in a 90’s European documentation. The integrated circuit used is not very common today.
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...