This is one of the many versions of this circuit that appear on this site. We got it from an internet documentation.
This circuit for link or alarm was found in the Encyclopedia of Electronic Circuits Volume 5 of...
This circuit is from a Popular Electronics of the 90's. Any power MOSFET can be used. The circuit...
This circuit extends the scale of a milliammeter. We found it in a documentation from the 60's. The...