Sinatra,
Finally I study well your sollution, it's OK that a delay is w t0, I was simultaing how the method works, and work's ok for phase changes, you can get phase changes when you compare a periodical signal with it same signal delayed, if signal changes, when you compare it with the same signal some time ago, you will see that the signal changes itself, and its the result, if phase changes, I can have it result.
Thanks sinatra, it's whats i'm looking for.