Re: Why PT's?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Edward Wingate <ewing7-at-rochester.rr-dot-com> 

Tesla list wrote:
 >
 > Original poster: "Lau, Gary" <gary.lau-at-hp-dot-com>
 >
 > Here's a question I've always wondered about.  As I understand it,
 > potential transformers are devices designed to step down a 14.4kV or
 > whatever transmission line to a more manageable 120V signal that can be
 > more easily read by the utility companies, so they can see what's
 > happening on their HV lines.  Basically a step-down transformer with a
 > precise turns ratio and a minimal power handling capability, but happily
 > enough so that it's useful in "our" application.
 >
 > These are big, heavy devices.  I would think that a solid state
 > optically isolated equivalent could be easily produced.  Why are these
 > dinosaurs still used by the utility companies?  And why a 120V output?
 > I'm grateful that these devices work so well for our application but...
 >
 > Gary Lau
 > MA, USA

Hi Gary,

Solid state devices are gradually replacing potential transformers,
that's supposedly the reason there are fewer of them showing up at the
famous "yard" in Richmond, VA that has been shown on some of the TCBOR
Video Report tapes.

Wishing everyone a Happy Thanksgiving,

Ed Wingate RATCB