This power source was found in a 1968 Electronics World. The transistors are from that time. The current of each output is limited by the transformer.
This circuit was obtained in a 1975 documentation. It is intended for old vehicles that still use...
With this circuit it is possible to select transistors and their compliant test. Or circuit...
This power supply circuit with selectable voltages was found in the June 1979 issue of Radio...