Found in RCA documentation from the 1960s, this 60 V regulator has a 100 V input and a current of 1 A. The transistors are from that time. One can try to use modern equivalents.
This assembly circuit using a small motor as a generator was found in Radio Electroics magazine from...
This 80s signal follower makes use of an audio amplifier of the era. The circuit can be adapted to...
This circuit is from a documentation from the 70s. Thus, the original transistor no longer exists,...