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Re: H2 driver



Subject:  Re: H2 driver
  Date:   Sat, 31 May 1997 08:38:23 -0400 (EDT)
  From:   richard hull <rhull-at-richmond.infi-dot-net>
    To:   Tesla List <tesla-at-pupman-dot-com>


At 04:51 PM 5/30/97 -0500, you wrote:
>Subject:     Re: H2 driver
>       Date: Thu, 29 May 1997 08:14:20 -0700
>       From: gene lambert <tesla-at-cyberverse-dot-com>
>Organization:  Tesla Electric, LTD
>         To:  Tesla List <tesla-at-pupman-dot-com>
>        CC:   tesla-at-poodle.pupman-dot-com
> References:  1
>
>
>Tesla List wrote:
>> 
>> Subject: H2 driver
>>   Date: Wed, 28 May 1997 20:55:20 -0400 (EDT)
>>   From: richard hull <rhull-at-richmond.infi-dot-net>
>>     To: tesla-at-pupman-dot-com
>> 
>> All,
>> 
>> I just cobbled up my table top maggey driver to monkey around with some
>> ideas which may make maggey 13.  I am labeling this table model maggey
>> 12.
>> I am using a Hydrogen thyratron 3C35 for the switch.  I am pulsing it at
>> a
>> 1khz rate and its uses about 80-100 watts from the DC supply in this
>> mode.
>> I have the driver just running as a simple coil here now and I get about
>> a
>> 4" spark when tuned to resonance (500khz) and approached with a grounded
>> rod.  It is bright and noisey (k=.55).  I am worried that it is still
>> too
>> high impedance a driver due to the high Q developed by an otherwise low
>> Q
>> circuit!  The darned tube actually supplies current to the primary tank
>> for
>> 1.6 usec (far too short-I think).  The coil, due to a large 12"X4"
>> toroid,
>> doesn't break out and a stub antenna 10 feet away collects the RF soup
>> into
>> an Oscope.  I count 50+ rings in the beautifully decremented envelope.
>> A
>> huge Q for this coupling! (by normal cogitatin').  I just have to work
>> on
>> the phased back to back idea.
>> 
>> A normal neon 60 ma 6KV AC tranny with a rotary gives about an 8" spark
>> at
>> 160 watts.
>> 
>> The coil is a 10.5 diameter by 6" tall form wound with 20 ga. wire.  the
>> primary is RG 214 of 5 turns.  Cap is ~ .008ufd and the tap is at about
>> 18-20uh.
>> "Sqwat and Hot".
>> 
>> I'll keep you folks up on this one.
>> 
>> Richard Hull, TCBOR
>
>Richard:
>Please keep us posted. Question; Have you tried perhaps using two tubes,
>like you mentioned before? Also, since you mention that tubes don't
>conduct long enough, couldn't a  driver circuit, be designed to allow
>you to increase the on-time? I know this would also increase the heating
>of the tube being used. This would be a good time to use a tube with a
>greater plate dissipation, or two tubes, either in parallel.  Or, like
>in many amplifiers, in a 'push pull' configuration.
>
>Gene Lambert
>
>
Gene,

H2 Thyratrons are on-off devices like SCRs.  Their on time is limited by
the
current reversals. (which snap the tubes off).  Plate diss;pation is not
a
problem with these tubes and a normal vacuum tube can't handle the
voltage
or currents needed in Tesla switching.  To my knowledge on the H2
Thyratrons
have this capability in the tube world.  Yes their are custom tubes at
$10,000 each, but the H2 units are hamfest buys at $1-5 each.  Solid
state
devices are out of the question, of course.

Richard Hull, TCBOR