Downtime Analysis

Hi everyone, I am looking forward to solve this problem:
Example:
Downtime Explanation.jpg
Better quality: http://postimage.org/image/krj3hfqgn/full/

COL 1 is the Input data from Input worksheet, now..if in COL 1 between the times is 3 or more minutes gap, it is known as downtime. I want excel to recognize downtime after 3 or more minutes gap between two different times in (COL 1), and export or (mirror) those two different times in to COL 2, so that i can see without me lookin into COL 1.
Than show the acctual gap time for each downtime in the COL 3 as shown in the example on the left.

The whole point is,COL 1 is going to be an input, and the rest is going to be automatic, without me looking into the COL 1 myselfe, and picking out two different times with 3 or more minutes gap, and importing them into COL 2.

What formulas,functions i have to create, examples would be nice Thank you!