In the figure we have the way to use the transistors of an old-paired pair as a trigger circuit. The circuit is by Philips from an old documentation.
This high-performance circuit was found in the 1982 SGS Linear Integrated Circuits Manual. The...
This circuit was found in Radio Electronics magazine from the 90's. The circuit is for small NiCad...
The circuit in the figure is a comparator for negative voltages, and a pair of polarization...