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 an Electronic Design from the 90's, this circuit uses an SCR according to the controlled power....
This circuit was found in an English publication from 1967. The circuit is for listening on a...
This is the traditional configuration of an OR gate using a voltage comparator, but it can also be...