This circuit for cars of the time was found in a Popular Electronics magazine from the 90s. The circuit is based on CMOS logic that is common even today.
Quadrature Generator for Transistor and SCR Testing This circuit was found in US 1980s...
This circuit, with output currents up to 500 mA, can stabilize or regulate the output voltage of a...
This circuit that uses only transistors that are still common was found in a 1995 documentation. The TIP41...