I wanted to check with y'all that this is a sane voltage implementation. [Yes, I know that circuit protection is a subject that has been beaten to death by the internet, but please bear with me.] Where the zener is rated for the max voltage the load can take And the resettable polyfuse is rated for min(Load_max_current,zener_max_current) [Ramblings below. Above is my real question.] And ideally, the zener is rated for a current higher than that of the load. Maybe a darlington pair with a zener connected (anode to base, cathode to collector). In that case, the zener would be rated for (load voltage + turn-on voltage of darlington pair), correct?