Current Monitor
![](https://freecircuitdiagram.com/wp-content/uploads/2010/03/Current-Monitor.gif)
On the circuit diagram, R1 is used to senses current flow of a power supply. We could use JFET as a buffer because Id=Is, therefore the power supply current flow is accurately reflected by the output monitor.
Here’s the circuit diagram:
[Source: National Semiconductor Application Note]