I would like to turn off and on a circuit by another circuit. I believe that could be easily achieved by a transistor but when there is a voltage regulator and an ESP8266 with wide range of input current I'm lost.
I have the ESP8266 programmed to send a notification when it's turned on. The V1 supply has unfortunately too low current to power the ESP so I have to power it by the V2 (4xAA 1.5V batteries should be probably enough to feed the voltage regulator 3.3V + 1.1V it's dropout and some transistor dropout)
The circuit below is my amateurish attempt that can be probably all wrong.