This circuit was found in a 73 magazine for radio amateurs from the 90s. The circuit uses high voltage transistors and the relay is high voltage as well.
This control for motors up to 1.5 A was found in the SGS manual of linear integrated circuits. The...
This circuit inverts the signal of any logic using a general purpose PNP transistor. The supply...
This configuration applies to other operational amplifiers in the same family. The circuit was found...