how choronograph works?

Question

how does a choronograph works on a watch??

Answer 1

A Chronograph is nothing more than a simple counter that counts time elapsed.
In Digital watches, there is a digital "clock". When you press start, a digital counter counts how many clocks go in. When you press stop, the counter divides that number with the clock frequency and you get minutes and seconds.

In analog watches, it is pretty similar. You have a minutes wheel and a seconds wheel. Every 60 sec the "minutes" wheel steps one notch. So, when you stop, you know how many minutes/seconds elapsed since start.