This circuit was found in a 1969 EEE. The circuit uses transistors from the era that can be replaced by modern equivalents.
I found this circuit in an English magazine from July 1982. The circuit is still viable by using...
The circuit shown was found in the 1994 National Semiconductor's Linear Application Handbook. The...
This solar powered circuit was found in a 1991 documentation. The transistor is a general purpose...