Re: Why bother with MOT voltage doublers?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Gregory Hunter by way of Terry Fritz <twftesla-at-qwest-dot-net>" <ghunter31014-at-yahoo-dot-com>

Hi Paul,

Good points you brought up.

--- Tesla list <tesla-at-pupman-dot-com> wrote:
> Original poster: "Paul Arrowsmith by way of Terry
> Fritz <twftesla-at-qwest-dot-net>"
> <p_t_arrowsmith-at-hotmail-dot-com>
> 
> I have been using two MOT's and a diode clamp
> circuit as per in microwave 
> ovens, an arrangement used by many coilers on this
> list. This of course is 
> not a true voltage doubler but but does render 12KV
> peak pulsed DC or 
> another way of looking at it AC with the one of the
> sine wave peaks at 0 
> Volts. It was an improvement on just 2 MOT's with
> the secondarys in series.
> Been using it to power a small magnifier with a
> .056uF in the primary tank 
> and a static series gap.
> Have since tried using a 5KV RMS (only 7KV peak)
> transformer with no diode 
> clamp circuit which delivers a significantly
> stronger and longer spark than 
> the 12 KV pulsed DC power supply. The 12KV pulsed DC
> needed 3 gaps of wider 
> spacing while the 5KV AC preferred two gaps of
> narrow spacing.
> Using 4 MOT's with series secondarys giving about
> 8.8KV RMS AC outpreforms 
> the 12KV DC by about 100%. In theory I thought this
> should give  similar 
> results to 12KV DC.
> Considering I can buy old uW ovens a the local tip
> here in Australia for $10 
> Aus each why bother with the doubler circuit?

I tried just using two series MOTs for about 4200vac,
but I had to set the spark gap so narrow it would
power arc within 30 seconds or less. I added half-wave
voltage doublers so I could open up the spark gap wide
enough for reasonable quenching, and performance
increased dramatically. 5 foot sparks from a 4" x 24"
coil were pretty neat. The power arc problem went away
too.

> Is the voltage dropping under load? or does it not
> like magnifiers?
> Or have I missed something like not putting a large
> reserve cap across the 
> output?

I don't know why the voltage doubler circuit isn't
getting the job done for you. I didn't use any filter
cap across the output. I applied the pulses directly
to the tank cap, and it drove my Tesla coil insane.

> Any thoughts,
> Paul A.
> 

_________________________________________________________________
> Get your FREE download of MSN Explorer at
> http://explorer.msn-dot-com/intl.asp
> 
> 

Regards,

Greg
http://hot-streamer-dot-com/greg


__________________________________________________
Do You Yahoo!?
Find the one for you at Yahoo! Personals
http://personals.yahoo-dot-com