Re: RE- Secondary wire &

Subject:      Re: RE- Secondary wire &
       Date:  Fri, 06 Jun 1997 20:28:00 GMT
       From:  robert.michaels-at-online.sme-dot-org (Robert Michaels)
Organization: Society of Manufacturing Engineers
         To:  tesla-at-pupman-dot-com

        An (another!) fairly decent rebuttal post from Mr.
        Skrocki (God, I hate those kind!).   Many of the
        points he makes are well taken (must he keep doing
        that?!), but I'd like to offer up a precious-few
        (I promise) counter-comments:

T>  From:  "Alfred A. Skrocki" <alfred.skrocki-at-cybernetworking-dot-com>
T>    To:  Tesla List <tesla-at-pupman-dot-com>

T>oN Wed, 04 Jun 1997 08:07:00 GMT Robert Michaels
T><robert.michaels-at-online.sme-dot-org> WROTE;

T>>         -- Making a space-wound coil using a closed loop (as a
T>>                 spacer) with a weight attached is effective, but I'd
T>>                 scarcely say it is "easily" done.  In fact it
T>>                 any machine or power-driven winding of a coil.

T>Before I got my lathe I wound all my coils by hand and I never found
T>any difficulty in using a closed loop with a weight as a spacer, but
T>then I learned how to cut threads bare handed with a file so I guess
T>it's a matter of ones background.

        I've never heard of using thread before your earlier post.
        Interesting.  What does it mean to "...cut threads bare
        handed with a file..."  ???  (also, ??!!?!!??, on second

 [ ... ]
T>>                 In my experience, the closed, weighted loop is best
T>>                 made itself of magnet wire.

T>That I agree on! The best is to use the same wire your winding the
T>coil with. I also feel it's important to have a sticky base to wind
T>on so the spacing wont be for nil! I like thin double sided tape to

 [ ... ]

                BTW - It's possible to purchase bi-filar magnet
                wire (and tri-filar for that matter):  2 (or 3)
                parallel strands the entire length of the spool,
                lightly stuck together (like the two conductors
                of electrical lamp cord).  I wonder -- might it
                be possible to wind a coil with bi-filar wire
                and then unwind one of the, er, ah, um, "filars"
                to obtain a space-wound coil?  Of course, it's
                enamel-insulated magnet wire.

T>>         -- In all but the highest powered Tesla coils, the
T>>                 turn of the secondary is apt to be below the
T>>                 voltage of the wire enamel.
T>>                 Consider:  A 500-Kv coil having a thousand turns
T>>                            in it's secondary  (Love those round num-
T>>                            bers!).   That's 500-volts/turn.

T>Huh! Accept for my very first coil (somewhat of a disapointment) I
T>NEVER use more than 600 turns on a secondary and of lately I a
T>getting better output with no more than 300 turns! This means my
T>coils would require a bit over 3 times the dialectric strength in the
T>wire insulation than your example.

T>>                         Which means, the wire enamel must withstand
T>>                         250-volts. Not a major challenge for today's
T>>                         wire enamels.   Comprendo, compadre -

T>In the comparasin to the coils I wind I would need over 1700 Volts of
T>insulation and I haven't found any enamel wire that holds up at that

 [ ... ]

        Point made and taken -- in the modern idiom of coils without
        much coiling in them.

        My principal point is:--  To consider turns-per-volts.
                                  To remember that adjacent turns
                                    are insulated by  =two=  layers
                                    of enamel (or cotton) (or gutta-

        I used 1000-turns only because it's a nice round number.
        There are days when I hate the idea of having to divide
        500 by 300  (The results of my calculations are apt to be odd-
        enough as it is) (!).

        BTW -- There are wire enamels spec'd to 600-volts/mil
               (meaning it would tolerate 1200-volts/mil per
               turn).  Not a standard item you may be sure, but
               not so rare a one either.

        Also -- for the hi-buck boys -- or those lucky at love
        or more particularly at scrap dealers -- Teflon-insulated
        wire for aerospace use may be had.  The Teflon can be
        as thin as wire enamel.  (The wire can be found silver-
        plated as well  {there's nothing quite like living
        right} ) !

                                Gutta-percha, yesterday, today,
                                and tomorrow, in -- Detroit, USA

                                Robert Michaels