This simple low current circuit was found in a Radio Electronics magazine from August 1960. The circuit does not use transistors in regulation, but only zeners directly.
Found in a magazine from the '90s, this circuit uses an integrated circuit from the era that is...
This circuit, found in documentation from the 1990s, uses a common 7-segment LED display. The...
This circuit provides precise signals of three frequencies, using CMOS technology. The integrated...