We found this circuit in a 1967 American documentation. It is a transmitter for animal research, monitoring intestinal pressure. The operating frequency is 22 kHz.
This amplifier was found in a 1970s documentation. Darlington transistors can be replaced for modern...
This “test your nerves” game was found in old documentation. The SCR can be of any sensitive type,...
Applying a 38 kHz signal at the input of this circuit (multivibrator) we can have stereo...