I think I answered this before. THIS circuit will work until 4.5v from 18v. by adding a regulator then it will work until 4.5v +2. You should add a regulator only if the timing is essencual. if you do that then use only for the lm555 timer and at the AND gate add a pull up to battery that makes an AND gate as opposed to open.

 

I think I answered this before. THIS circuit will work until 4.5v from 18v. by adding a regulator then it will work until 4.5v +2. You should add a regulator only if the timing is essencual. if you do that then use only for the lm555 timer and at the AND gate add a pull up to battery that makes an AND gate as opposed to open.

And the LEDs and the transistors driving them? That has been the subject of conversation.