RE- Violet Ray Tesla Coil

Subject:       RE- Violet Ray Tesla Coil
       Date:   Tue, 03 Jun 1997 08:18:00 GMT
       From:   robert.michaels-at-online.sme-dot-org (Robert Michaels)
Organization:  Society of Manufacturing Engineers
         To:   tesla-at-pupman-dot-com

        The construction you describe is virtually identical to that
        of the high-vacuum leak testers widely used in laboratories
        and available from dealers in chemistry/physics apparatus.

                How accurate it is to characterize these as Tesla
                coils is highly questionable -- tho I won't re-
                peat my diatribes on the subject here (you're

        When purchased new, the vacuum-leak testers come with dire
        warnings about not using the adjustment knob to turn the
        tester on and off.  I'm here to tell you the warnings are
        not without basis:

                | Use the adjustment knob as an on-off control |
                | and suffer the consequences.  You have been  |
                | warned.  This is the voice of experience.    |
                |                                              |

        It is my sense that the coils sold for violet-ray use are
        not as powerful as those sold as vacuum-leak testers al-
        though they appear to be similarly-constructed.

                                        Yours for truth in coiling,
                                        in -- Detroit, USA

                                        Robert Michaels

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

T>Hi all, I purchased another hand held "Violet Ray" machine at a
T>flea market over the weekend for $5.00. The unit didn't work at all
T>so I opened it up and studied the insides, below is an ASCII
T>schematic of what I found. Please excuse the ASCII art!

T>                                    |   |
T>    socket for evacuated tubes ---> |   |
T>                                    |___|
T>                                      )
T>                                      )
T>                                      )
T>                                      )
T>                                      ) S
T>                                      )
T>                    __________________)
T>                 VG ____  _|_         )
T>                      | | ___C        )P
T>                     #( |__|__________)
T>                   C #(    |
T>                   O #(    |
T>                   I #(    |
T>                   L #(    |
T>                      |    |
T>                       115V
T>                        AC

T>There is an iron core coil connected at one side of it's windings to
T>the line. The other side of the coil connects to a vibrating armature
T>almost identical to those found on the old induction coils. The
T>stationary contact of the interrupter is connected to a 5 turn tesla
T>coil primary P made of 2 no.20 double cotton coated wires, the other
T>side of the primary is connected to the tesla coil secondary S which
T>is very fine wire (No.36 - 40) wound on a wooden form 3/4 inch in
T>diameter and 2 1/2 inches long. the primary also connects to the
T>moving contact of the interrupter and there is a paper capacitor C
T>across the vibrating spark gap VG. There is an adjusting screw that
T>pushes the moving armature of the vibrating spark gap closer to or
T>further away fro the stationary contact. The spring was over bent in
T>the unit I purchased so I rebent it back into position. The unit then
T>worked and yielded snappy thin bluish white sparks about 2 inches in
T>length at the best position of the adjustable control. Sorry I can't
T>provide any measured values for the inductance, capacitance, voltages,
T>ect. but one of my kids stole my multimeter! Grrrrrr. The unit is
T>about 10 inches long and 2 inches in diameter and made of black
T>bakelite, it looks identical to the Tesla coil vacuum testers except
T>it is designed to hold evacuated glass tubes instead of the pointed
T>metal probe. The only markings on the unit were;

T>                     20w  115V
T>                      No. M66
T>           The Master Electric Co. Chicago

T>I find their use of a vibrating spark gap in series with the line
T>through a choke to be interesting. Its circuit looks identical to the
T>circuit described in Thomas Stanley Curtis's "High Frequency
T>Apparatus" 1916 (reprinted by Lindsay Publications 1988)in chapter
T>VIII "Kicking Coil Apparatus".