Hello again. Finally I implemented the circuit in the first post with some modifications due to lack of availability of some components.
The first time i tested the circuit i removed the battery in the UPS of my desktop and used it. This worked perfectly.
Anyway i needed the battery for UPS, so i bought a new battery of the same brand (exide 12V 7AH) and tested for the second time my router got damaged, it is dead now.
While testing first time i used step down t/f for input but the second time i kept the step down t/f aside to finish the connections neatly.
While testing second time the last connection i put was router terminals to 1N5408 and instantly i saw sparks in the breadboard.
I also posted my breadboard connection screenshot , please find my mistakes on it.
Anyway I spent a lot of time on it and i wanted to know what did i do wrong.
Below are the orginal and modified circuits . Please tell me what to change and what to keep.
Original Circuit
Modified circuit
I made the circuit on a bread board even the bread had burns on it.
Please help me this time , May be i'll be careful next time.