Turn off transistor at some voltage

[mister_rf]

They have answered well just use a PNP instead of an NPN.

:roll:

Please elaborate how to implement this solution...

 

[mister_rf]

@nmbg011
If you are looking for a most accurate solution need to use a TL431 adjustable precision shunt regulator. See the new diagram attached.

 

[mister_rf]

Here is a simplified functional diagram… :-D

 

[nmbg011]

I will try this with shunt regulator TL431, I dont have it, but i will get it from shop.