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.
This battery status indicator was found in American documentation from the 1980s. The integrated circuit...
This input circuit for an oscilloscope was found in Radio Electronics from the 90s. The operating...
The resistors in this circuit marked with * must be within 1% tolerance. The circuit is from the...