We found this circuit in a 1985 documentation. The transformer is an old TV flyback that has an exposed part of the core, where 10 to 20 turns of common wire are wrapped.
We found this circuit with an operational transconductance amplifier in the Motorola Linear...
Originally the circuit in the figure is indicated by National for the control of an electronic car injection...
This small two-transistor amplifier was found in the April 1994 issue of Electronics Now magazine. This...