This circuit converts negative logic signals to positive logic signals. We found it in 1969 documentation. Current equivalent transistors can be used.
This circuit for cars with fans was found in Silicon Chips documentation from the 90s. It is used...
The frequency of this circuit, which uses one of the LM139 comparators, depends on C1. The circuit...
This interesting high-quality amplifier configuration was featured on the cover of the June 1994...