Re: RE- Re: Bombarder xfm

Subject:        Re: RE- Re: Bombarder xfm
       Date:    Tue, 10 Jun 1997 12:59:00 GMT
       From:    robert.michaels-at-online.sme-dot-org (Robert Michaels)
Organization:   Society of Manufacturing Engineers
         To:    tesla-at-pupman-dot-com

This message was originally addressed to JIM.FOSSE-at-BJT.NET
and a carbon copy was sent to you.
r>From: jim.fosse-at-bjt-dot-net (Jim Fosse)

 [ ... ]

J>>  Such
J>>        can cause  =brief=  (sometimes very brief) internal arcing
J>>        which in turn can cause an internal open circuit in a trice
J>>        (which is also very brief).

J>which would cause (in a thrice) the 3/16" pit 3/4 of the way down my
J>"first" blown neon's secondary. (as I found out after I depotted it).

J>I don't believe that the neon's max current could have caused this
J>sized hole because it just doesn't have enough energy to blow a clean
J>hole in a copper/fish paper/tar composite;)  But, the short circuit
J>current from my ~14nF (aka14,000 micky-mikes;) rolled cap (or any low
J>Esr/Esl cap) WOULD blow a hole in the neon's secondary.

        Could not your pit be due to sustained internal arcing??

 [ ... ]

J>>        I'm not saying your basic premise is wrong, only a little
J>>        oversimplified -- and apt to be mis-applied by some readers.
J>>        Hey -- I'm the guy who unabashedly advocates wholesale over-
J>>        volting (but not over =powering=) military-spec.
J>>        so we are both brothers of the Cause.
J>Yes it was.  I had left out all my assumptions.  I stated a rule of
J>thumb without stating ALL the assumptions that go along with it.

J> So Robert M.,  What rule of thumb do you suggest for this
J>        transformer?

        I'm inclined to rely on physics, rather than rules of thumb
        (not that they don't have their place.  Sometimes.  Maybe)

        If I had a "rare find" transformer which I really treasured,
        I'd stick in a thermocouple (perhaps a thermistor) and watch
        the temperature like a hawk, at least until I was fully
        confident about what it'd take.

        Even more desirable is to use several thermocouples in
        adventitious places.

        Even more than desirable would be having those theromcouples
        feed a temperature alarm -- or a controller which would shut
        the system down at excessive temps.

        If/when such a transformer is under rebuild, I'd say stick
        in a few miniature thermoswitches which would accomplish
        the above much more cheaply.  They are widely available and

                                        Physics! (that's  =my=  "rule
                                        of thumb"), in -- Detroit, USA

                                        Robert Michaels

cc: Tesla List [tesla-at-pupman-dot-com]