This 12V stepper motor controller was found in the August 1996 Electronics Now magazine. The circuit has a pulse input and the MOSFETs can be of virtually any type.
Using the name of varactor this circuit was found in the Radio Electronics magazine of July 1982....
In the figure we have a differentiator with the LM3900 transconductance amplifier. The circuit is...
This is one of the many approaches we have on the site for this low power 0.5 W amp using the...