This circuit is from a 1968 documentation. It makes use of thermistors (NTC) to indicate overheating of charged batteries. Modern equivalent components can be used.
This simple regulated power supply was found in a 1977 documentation. The zener diode determines the...
This circuit was obtained in a 1977 Radio Handbook. The transistor is from the era and the coils...
This circuit uses matched transistors. The circuit is from Electronics Now magazine and has a...