I'm trying to regulate 12V to 4.7V with a zener diode. (I'm doing this to protect an AVR's gpio pin, so the current is very low.) I tried the simplest circuit with the zener, but it does not work as expected.
I expect the multimeter to measure 4.7 Volts on the zener diode, but it only shows about 3.2-3.3 Volts. I replaced the diode with other ones with the same model, and the results are the same.
Are my diodes faulty, or am I doing something (very) wrong?