This circuit can work with almost any JFET. The circuit is from an Electronics Now from April 1993. It is powered by a 12 V battery, but can also be powered by 9 V.
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...