This circuit is from a 1969 Electronics World. The transistors may be modern general-purpose equivalents. The circuit is for frequency ranges between 250 Hz and 250 kHz.
This 3V-only circuit was found in old American documentation, but can be implemented with...
The output voltage of this circuit, which can regulate the current in a load between 0 and 1 A,...
This circuit was found in a Popular Electronics from the 90s. The circuit has temperature...