This active tone control circuit was found in American documentation from the 90's. The transistor can be general purpose or low noise with high gain.
This 1 A circuit was found in a Philips documentation from 1966. The transistor is of the time,...
We found this circuit in a Popular Electronics of the 90s. The circuit can also be used as a seat...
This two-digit timer was found in the 1983 Special Projects issue of Radio Electronics magazine. The...