Following is the circuit I have been analyzing. My intention is to calculate the turn on and off condition of the transistor Q1. R1 and R2 (10 kΩ each) are internal to the transistor.
Following is my understanding, whenever there is voltage at the input V1, it will equally divide across R1 and R2. When it reaches 0.7 at Vbe, Q1 will be turned on. If I want to increase the turn on voltage of the transistor, introducing voltage divider at the input (before resistor R1) will be sufficient.
I want to on and off the transistor above to a fixed voltage, say 5 V. Please advise my understanding.