I am working on a project where I need a variable voltage from 4-12V. to make I can regulate input voltage to keep the voltage below 12V, and I am thinking of using a zener diode combined with a transistor to block current below 4V. Will this work?
note: adjusting the voltage works, I only need help with the cutoff.
schematic:**broken link removed**
note: adjusting the voltage works, I only need help with the cutoff.
schematic:**broken link removed**