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.
This circuit was found in February 1976, Radio Electronics magazine. The circuit is powered by 12 V...
This circuit was obtained in a 1973 publication, being implemented with TTL technology. The...
Found in a 1969 documentation on neon lamps, it actually takes advantage of the durability of the neon...