Phase Comparator

[BIGEYE]

When cleaning out an old shed/workshop, I came across a phase comparator
made by Pfisterer.
This is a hand held unit and may be for use on HV systems judging by the
look of the leads and looks hardly used.
Could anyone tell me what these instruments are for and what the value might
be.

TIA

 

[Don Kelly]

----------------------------

One stage of a phase locked loop?


Use it to put 2 generators in phase and keep them in sync by using an
error
voltage as a control.

 

[krw]

Thirty years ago I was asked to update a phase-rotation sensor for
mainframes (their phase-controlled power supplies didn't like to be
plugged in backwards and backwards blowers didn't work well .
LEDs don't work so well in this application. They use a lot of
current at a low voltage (low impedance), thus load/upset a phase
delay circuit. The answer was a 'D' flipflop on a bridge between
the phases. That was sensitive to zero-crossing distortion, but a
solvable problem.