This circuit was obtained in a Popular Electronics from the 90's. The gain depends on R4 and R3. Transistors are general purpose types.
This circuit was obtained from ancient American documentation. The circuit combines a JFET with a...
In the figure we have an application of an oscillator 4013 as voltage multiplier. It consists of a...
Found in Linear Technology documentation from the 1980s, this circuit has an accuracy of 0.01%....