I'm studying the schematic for an electronic load available as a kit from Jameco: http://www.jameco.com/Jameco/Products/ProdDS/2161107%20Schematic.pdf
There is a Schottky diode shunting the source-to-drain nodes of the MOSFET, D1 in this simplified schematic:
The kit instructions describe its purpose as: "used to protect the MOSFET from voltage transients".
I've searched and searched and can't find an explanation of how it would do that. I've found circuits that have a Schottky placed this way, but they do that for improved performance in switching power supplies and similar applications.
Would this diode do anything useful in this circuit or should I just leave it out?