The idea is to protect the input stage of a control card from improper power supply connection. The power supply is a standard desktop AC-DC power adapter (Meanwell GST160A12) with inbuilt shortcut, overload and overvoltage protection. Since other models are used (Meanwell GST160A15) the risk for improper connection and operation is high. The control card needs an input of 12V and draws circa 12 A. How should a circuit be design in respect with efficiency and simplicity? There is no problem in brutally shorting the power supply adapter. I was thinking in just placing a Zener diode of correct rating that can turn on when the voltage is above 12V and short out the PSU. Would this be a very bad design?