This simple circuit has good gain and can be implemented with any general-purpose transistor. The circuit is from Electronics Now, June 1997. The coil determines the frequency range.
This circuit, in addition to transforming a sinusoidal signal into a square, shifts its phase. The...
The transistors on this circuit can be the BC548. The circuit is from English documentation from...
In the figure we have three voltage doubler configurations that can be used in high and low...