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Re: [TCML] Voltage/power dissapation drop across HV DC current limiting resistors.



'1:1 220VAC Cheap isolation transformers' seems to be the problem :)

Ive found many output 12VAC so id need to recitfy and regulate that. 

At this point id be ok with using the 15KV NST with 10x10MOhm 3.7KV resistors each side. It gives be a hundred microamps at .1 Watt max dissapation which is totally acceptable.

----- Reply message -----
From: "Atomic" <atomicrox@xxxxxxxxx>
To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
Subject: [TCML] Voltage/power dissapation drop across HV DC current limiting resistors.
Date: Wed, Sep 30, 2015 11:26 AM

As to your first question, yes, I think it'd work.

As to the second question, not sure, I've never tried anything of the sort
with wall-warts. Worst case hypothesis you could plug the wall-warts to
cheap isolation transformers.

On Wed, Sep 30, 2015 at 1:15 PM, msweeney23@xxxxxxxxx <msweeney23@xxxxxxxxx>
wrote:

> Replying to both last replies here. If i could chain two (output isolated)
> rectified flybacks could i not do the same for two isolated negative ion
> generators?
>
> Most wallwart xformers have no ground does that mean i can assume an
> isolated DC output or maybe measure resistance/capacitance of output to
> each AC prong to see? (I know these are not well regulated and the voltage
> may drift).
>
>
>
> Sent from my HTC
>
> ----- Reply message -----
> From: "Carl Noggle" <cn8@xxxxxxx>
> To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
> Subject: [TCML] Voltage/power dissapation drop across HV DC current
> limiting resistors.
> Date: Wed, Sep 30, 2015 9:53 AM
>
> A nonrectified flyback would make a good power supply for a hairy
> Cockroft-Walton.  If you do hose the diodes, you will lose about 20% of
> the output voltage due to the increased capacitance in the secondary.
> Usually the secondary is divided into four parts with the diodes between
> them in a big series string.
>
> ---Carl
>
>
>
> On 9/30/2015 4:26 AM, Atomic wrote:
> > I'm not sure why you don't want the rectified flybacks. You could just
> > power two of them from (separate) batteries or isolated PSUs and then
> > series the HV output, grounding the center tap. Then you'd have a
> positive
> > and a negative high voltage, low current output. I'd use a 555 oscillator
> > as opposed to a ZVS for to power them for this purpose.
> >
> > On Wed, Sep 30, 2015 at 3:58 AM, Carl Noggle <cn8@xxxxxxx> wrote:
> >
> >> Hey--I forgot to mention that there are four fectifiers in each unit.
> >> Most units have had the fectifiers replaced with rectifiers. Best not
> to do
> >> tech writing too late at noght.
> >>
> >>
> >>
> >>
> >>
> >>
> >> On 9/29/2015 4:53 PM, Doug wrote:
> >>
> >>> Hi Mat; I have 2 flybacks but do not know how to identify weather they
> >>> are old style or newer style, I have had them for a long time.
> >>> Doug
> >>>
> >>> On 9/29/2015 7:01 PM, David Speck wrote:
> >>>
> >>>> Matt,
> >>>>
> >>>> The large majority of potted flyback transformers available these days
> >>>> have integral rectifiers built in, because they were intended for use
> on
> >>>> CRTs.  If they have a long lead with a round anode cap on it, it's
> safe to
> >>>> assume that it has a rectifier in it.
> >>>>
> >>>> It's quite hard to find flybacks without rectifiers in them these
> days,
> >>>> unless you can find very old ones from tube TV sets.  Those sets used
> >>>> vacuum tube 1B3 rectifier tubes, 'cause effective solid state
> rectifiers
> >>>> weren't available at the time.
> >>>>
> >>>> The old flybacks without rectifiers tend to command high prices when
> you
> >>>> can find them on eBay.
> >>>>
> >>>> Removing the rectifiers from an epoxy potted flyback without
> destroying
> >>>> the hair-fine end of the HV winding is a very difficult proposition.
> >>>>
> >>>> Dave
> >>>>
> >>>> On 9/28/2015 11:19 PM, Matthew Sweeney wrote:
> >>>>
> >>>>> This is correct I am building a 'tandem' VDG using both positive and
> >>>>> negative polarities. I picked up two of those HV negative ION
> generators
> >>>>> just because they were so cheap and I can mess around and see what I
> >>>>> get.
> >>>>>
> >>>>> I though about picking up some flybacks but they don't say anything
> >>>>> about
> >>>>> having a built-in diode and I don't think it's easy to remove them. I
> >>>>> didn't see this deal and already ordered the ion generators, maybe
> I'll
> >>>>> check these out if the ion generators don't work as expected.
> >>>>>
> >>>>> Thanks again for all the info it's been very useful.
> >>>>>
> >>>> _______________________________________________
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> >>>
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