This circuit can make use of almost any operational amplifier and the diodes are for general use. It is intended to excite an analog instrument.
In the figure we have a small general-purpose amplifier with the LM386 integrated circuit and...
The presented circuit allows to control the valve of a tap. The positioning of the emitter and the...
This circuit is from a 1956 Sylvania publication. The transistor used is germanium and the old...