This Linear Technology circuit can measure currents from 100 pA to 100 uA. The circuit is from the 80's, using a component of the era. Transistors are general purpose types.
The Variable Frequency Oscillator (VFO) shown in the figure can generate signals in a frequency...
The focused circuit was found in the National Semiconductor's Linear Applications Handbook of...
The circuit is suggested by National Semiconductor in its 1994 Linear Applications Handbook. The...