Using the LM3909 this circuit was found in the January 1992 issue of Radio Electronics magazine. Resistor R1 should be chosen according to the table given next to the diagram.
The circuit in the figure is from a source with the possibility to adjust the output voltage from...
We found this circuit in an old magazine 73 of 1974. The circuit must be powered by a continuous voltage...
This circuit is from a 1987 American publication called Electronics Handbook. The circuit can be...