[Home][2018 Index] Re: [TCML] rectifying my NST [Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [TCML] rectifying my NST



 Charles,

Wow! 36” spark! That’s impressive. I happen to have a surplus x-ray transformer (with its internal diodes still intact) that I currently already have set up to be fed with the current ballasted 0 - 280 VAC output from my large Tesla coil control panel that would serve admirably for feeding a ‘man-sized’ Marx generator. I have toyed with the idea of building a big Marx bank before, but the challenge of its sound construction, both from an electrical as well as a mechanical standpoint, the unlikely prospect of procuring all of the required matching HV Caps and resistors on the surplus market and the consequential cost associated with obtaining the same on a retail market, and the total lack of space to safely operate such a beast have pretty well placed that project on the back burner for now. :-/

David

Sent from my iPhone

> On Jun 22, 2018, at 8:26 PM, charles rakes <crakes29@xxxxxxxxx> wrote:
> 
> I use a 15Kv 60ma NST with 30 diodes in series on each output hot
> terminal.  One string with a negative output and the other with a
> positive.    I get over 22KV DC output that I use to drive my dual 15 stage
> Marx generator and get about 36-inches spark between the two towers.  The
> NST's primary is controlled by a variac.
> 
> On Fri, Jun 22, 2018 at 2:14 PM, Matthew Sweeney <msweeney23@xxxxxxxxx>
> wrote:
> 
>> Hi Raymond, I did this using strings of cheap Microwave oven diodes potted
>> in short PVC tubs with paraffin wax. I also added some high wattage 1M
>> resistors for my own safety.
>> 
>> Basically I created large, clunky, cheap 30KV-50KV diodes :)
>> 
>> It worked well, but I think the diodes would be better off in epoxy
>> specific for the context. Rectified DC off an NST is a different beast and
>> kinda scary for me :)
>> 
>> I was using this to drive a VDG, but the voltage was too high and it's very
>> much overkill!
>> 
>> Good luck!
>> 
>> On Fri, Jun 22, 2018, 5:35 AM Raymond Spigot <raymond.j.spigot@xxxxxxxxx>
>> wrote:
>> 
>>> Hi, thanks for all the interesting discussion about NST testing and safe
>>> grounding, it's all been instructive for a noob
>>> 
>>> I have this grey resin block neon transformer in the shed I was thinking
>> of
>>> experimenting with.  It's a 15kv/30mA one with a midpoint ground
>>> connection.  Is there a way to rectify the output so I can use it for
>>> trying out powering a dc tesla?
>>> 
>>> I have a big bag of diodes (1N5408 I think) that were pretty cheap.  If
>>> they'll handle 1000v each I could solder them up into long strings and
>> use
>>> 4 strings of diodes to make a bridge rectifier?  I guess I'd need a
>>> capacitor on the other side of the bridge as well though to smooth it
>> out a
>>> bit.
>>> 
>>> Then I was wondering if there was another way to do it with a midpoint
>>> grounded transformer like mine.  I'm thinking the 2 secondary windings on
>>> the transformer must be out-of-phase, but could I rectify them
>>> individually?  Between each HV output and the midpoint ground I mean.
>> Then
>>> I'm thinking I'd need 2 bridges but they're only trying to rectify half
>> the
>>> voltage each and it would be easier to cope with.
>>> 
>>> Basically I'm hoping there's a way to get like 10kv dc out instead of
>>> closer to (I think) 20kv  Because then I can buy a main MMC capacitor
>> that
>>> doesn't have to be rated for the highest voltage (so I can put less caps
>> in
>>> series)
>>> 
>>> hope this makes some sense to someone! thanx for advice anyway
>>> 
>>> Ray
>>> _______________________________________________
>>> Tesla mailing list
>>> Tesla@xxxxxxxxxxxxxxxxxx
>>> https://www.pupman.com/mailman/listinfo/tesla
>>> 
>> _______________________________________________
>> Tesla mailing list
>> Tesla@xxxxxxxxxxxxxxxxxx
>> https://www.pupman.com/mailman/listinfo/tesla
>> 
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxxxxxxxxxx
> https://www.pupman.com/mailman/listinfo/tesla

_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxxxxxx
https://www.pupman.com/mailman/listinfo/tesla