Re: NST->DC Re: CGA Monitor Flyback ???

To: tesla-at-pupman-dot-com
Subject: Re: NST->DC Re: CGA Monitor Flyback ???
From: "Malcolm Watts" <malcolm.watts-at-wnp.ac.nz> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
Date: Tue, 22 Feb 2000 18:40:00 -0700
Approved: twftesla-at-uswest-dot-net
Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme

Hi all,
           I guess most would have picked this up but it begs a warning:

> Original Poster: "Jan Florian Wagner" <jwagner-at-cc.hut.fi> 
> 
> Hi,
> 
> before commenting, I'd like to ask a question along the same topic. To
> make a DC Tesla coil using a NST, can I use HV rectifiers on the NST
> secondary side? Or is this a bad idea with NSTs?

You can.
 
> > So now I am curious, Do you think this flyback is going
> > through a diode turning it into DC. 
> 
> I've also a tiny TC that uses a halfwave rectified TV flyback power
> supply, the diode built-in inside the flyback, but the power put into the
> system is too little to have a high firing rate. 
> 
> Maybe your flyback is way more powerful. 
> 
> As to the frequency, if you have the driver circuitry and all, the flyback
> will run at some kHz - personally I got best output at about 7kHz, but
> some claim these things will run in the order of 100s of kHz. 
> 
> When you connect the flyback directly to the mains, it will
> just act as a normal step up transformer, not like a flyback. The voltage
> could be below the possible output (is 12V->15kV or so in flyback
> operation), but if you drive it at a higher primary side voltage than
> intended, you could end up with the same output voltage.
> (this didn't answer much to what you asked, but anyway... :o)

I agree with the comments about transformer vs flyback actioon but I 
wouldn't advise connecting a monitor flyback transformer to the 
mains. reddened faces and popped fuses would be a likely result.
     Some basic transformer theory should be studied before 
advising applying arbitrarily high voltages to the primary of a 
transformer.

Regards,
Malcolm