Re: Saturable reactors?

At 07:44 PM 12/7/98 -0700, you wrote:
>Original Poster: "Bill the arcstarter" <arcstarter-at-hotmail-dot-com> 

>Anyway - this book describes the basics of a little-known-today 
>component called the saturable reactor.  Looks like if I had one I could 
>build a quite-unkillable pig controller out of it!

These devices have been largely replaced by silicon controlled rectifiers
(SCRs), which are smaller and less expensive and provide greater gain.
There are some advantages to saturable reactors however, they can be
designed for almost any voltage-, current-, and power-handling requirement.
They are tolerant of temporary overloads, and they are less inclines than
SCRs to produce high frequency transients which are troublesome to
sensitive and high-voltage circuits. 

There are two inherant limitations of the saturable reactor: voltage from
the ac power source induces voltage in the control winding by a transformer
action, and the response time is long. 

A major design headache is that the voltages, currents, and fluxes in the
core of a saturable reactor are related by the magnetisation curve of the
core. Since the operation of saturable reactors is dependent upon the
non-linear nature of the magnetisation curve, the lack of a convenient
analytic function to describe the magnetisation curve complicates the
design and analysis of saturable reactors. Approximate analysis is
accomplished by a combination of graphical and analytical techniques.

Safe coiling,

Gavin Hubbard