When an alternator is used to supply constant current, it needs an adjustment that must be made as shown in the figure. The potentiometers are of low wire value with high dissipation.
This telegraph monitor was found in an American documentation for radio amateurs from the 1970s. The...
We found this circuit in a European publication from the 1970s. The transistor is made of...
This adjustable source from 2 to 15 V uses transistors from the 60's, as indicated in the...