This circuit is from an 80's technical newsletter. The circuit can use any general purpose transistor and its power supply can be changed with a resistive divider to use a single 9V battery.
This circuit is from old documentation. The operational amplifier is uncommon nowadays. The...
This instrumentation circuit was found in the September 1989 issue of Radio Electronics magazine....
This JFET amplifier was found in documentation from 1958. The circuit has voltage gain of 4 and 10...