Accurate 60Hz phase delay : re-visited

[Freddybaby]

My original problem was in accurately measuring phase difference between 2 60Hz sources. Requirement is within a few 10ths of a degree.

I got the detector working pretty well but my problem is I see no delay in a 165FT section of coax using sine wave to analyze. With a square input I see about what I expect (215nS).

Am I seeing DC offset errors or am I crazy in thinking the delay will be different between signal types ?

Original post

https://www.edaboard.com/threads/209747/

 

[FvM]

The delay is in fact much lower than 1/10 degree, actually less than 1/200. Not quite sure, if your detector will see it?

 

[kak111]

FvM is right.

60Hz ____ 1 cycle ___ 360 degrees ___ time 16.7ms

1 degree ___ 46.3 µs

0.005 degrees ___ 263 ns

That means sine signal 1 Vpeak , phase difference 0.005 degrees
gives sin (0.005 [deg]) * 1V signal = 87 µV

You can use 100Vp for measuring or use two identical amp stage with A = 100
to find 8.7mV signal etc...

ref. my previous answer to " Accurately resolving 60Hz phase lag using attached schem "

Regards KAK