Re: 1920's Tesla Coil, Fischer Type H, 12 AMP !!

["Mike 'Viggy'" <vigorita-at-colorado.edu> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

I have a question:  What kinds of 'procudures' were these machines used for?

Viggy

At 05:30 AM 6/29/99 -0600, Tesla List wrote:
>Original Poster: Jeff Behary <jeff_behary-at-hotmail-dot-com> 
>
>Hello !
>
>I just received a 75 pound work of art! A 1920s Fischer Diathermy Machine, 
>type H.  It is more of a cross between a Tesla Coil and a d'Arsonval Coil, 
>approx. 12" x 12" x 18".
>
>Usually d'Arsonval coils are high current Tesla Coil primaries, from which 
>various taps are lead to outputs for varying voltages of high current and 
>frequency for surgical work.  This particular machine has a large knob in 
>the front that is attatched to a rack and pinion, which moves a primary coil 
>over a secondary coil to adjust coupling (ie, intensity of current).  The 
>secondary is almost identical to the primary, only one fits inside of the 
>other.
>
>This machine had a large transformer, usu. 3000 volts.  It has 2 series mica 
>condensers, and 5 MASSIVE finned stationary spark gaps with 1/2" tungsten 
>discs.  This is the "heavy dutiest" of any spark gap I've seen in a 
>diathermy machine, even more rugged than the typical Fischer gaps.  Very 
>high current.
>
>Now, the scary thought is that 12 amps of are being drawn from the mains.  
>These 12 amps charged the condenser and were passed through the gaps in the 
>usual fashion to the primary coil.  As the secondary coil is the same amount 
>of turns, the current induced in the secondary is EXTREMELY high -- and THIS 
>current was conducted DIRECTLY to the patient through metal electrodes.  If 
>these electrodes were not in DIRECT contact with the skin, an arc would form 
>instantly burning a hole in the skin!
>
>Patients were often petrified, and Fischers large manual has a chapter 
>devoted to preparing the patients for such scary treatments, and calming 
>those already scared out of their wits!
>
>Most of Fischers machines DID however have secondary coils made to give 
>"high frequency effluve" or hot sparks, as well as the above "d'Arsonval" 
>and "Thermo-Penetration" "Low/Medium/High" currents...however taps for these 
>later currents were taken DIRECTLY from the primary, meaning a mis-fire of 
>the spark gap leaves a patient firmly wired directly to a 3000V 6A 
>transformer...
>Not exactly OSHA approved!
>
>Jeff Behary
>
>
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---------------------------------------------------
Mike Vigorita
vigorita-at-colorado.edu