i have searched in over voltage protection (like mosfet ) , i wanted to use zener diode parallel so it wont dissipate power unless in over voltage protection , but its power is low so i read that i needs resistor to control the current passing through it .
but this resistor will dissipate power , so i thought if we can put resistor like this :
so in this situation resistor (R3) will only dissipate in case of over voltage but in desired voltage current wont pass through zener so wont pass through resistor .
so my questions are :
is the voltage going to led equals to source or to zener ?
is the new placement for resistor right? if wrong why?
is there another placement for resistor if this doesnt work ?