Re: [TCML] Trying another coil after 42 years

[Gary Lau <glau1024@xxxxxxxxx>]

I don't think it would be worth the effort to try a Cocroft-Walton
multiplier.  CW's are only worthwhile if the output current is very small.
I don't know how you'd go about sizing the Tesla coil tank cap for a given
CW power supply.  In a Tesla coil application, you need every bit of current
to charge the cap, and even if the efficiency was 100%, if you only have
4.5W to start with, it won't be impressive.  It would be way, Way, WAY
simpler and impressive to just start with an NST of any size or oil burner
ignition transformer.

Regards, Gary Lau
MA, USA



On Sat, Oct 2, 2010 at 8:33 PM, Bill Washburn <billwashburn@xxxxxxxxxxx>wrote:

> Gregory,
>
> I have a couple of "FLPS - Power Supplies - for Cold-Cathode Lamps" and
> thought I'd use one of these with
> A one stage High-voltage amp to push the current up.  In addition several
> stages of cocroft-Walton might push the
> Voltage up where it will need to be.
>
> The DigiKeyCXA-L10L runs at 4.5W, 900V and 30KHz..
>
> Could I start with one of these and/or amplify/multiply (or at 4.5W would
> simple voltage multiplication work)?
>
> Thanks, Bill
>
>
>
> -----Original Message-----
> From: G Hunter [mailto:dogbrain_39560@xxxxxxxxx]
> Sent: Saturday, October 02, 2010 8:15 AM
> To: Tesla Coil Mailing List
> Subject: Re: [TCML] Trying another coil after 42 years
>
> Hi Bill,
>
> Welcome back to the insanity...
>
> > When I was a youngster I built a small Tesla transformer
> > with an old Model-T
> > spark coil and a capacitor made of a piece o glass with
> > tin-foil electrodes.
> >
> > The primary was two inches or so in diameter and the
> > secondary was one inch
> > or so at about six inches in height.
> >
> > It performed well.
> >
>
> Yeah, I made something similar when I was a teenager.  Powered it with a
> car
> ignition coil and a dimmer switch.  Glass plate capacitor, machine bolt
> spark gap, 2-3" streamers and lots of purple corona.  I was mesmerized.
>  Had
> my parents known what I was up to, they probably would have stopped me.
> I've been tinkering with the hobby--on & off--roughly 35 years now.
>
> >
> > I'd like to recreate this same coil but with a 555 timer
> > source or some
> > other small AC source.
>
> Are you trying to avoid 120vac operation for some reason?  Also, I'm not
> sure how you'd work a timer chip into a TC.  If you want to keep a small,
> table top coil simple & reliable, I suggest a car ignition coil & dimmer
> switch for the power supply, or better yet (much better) a small neon sign
> transformer or an oil burner ignition coil for the power supply.
>
> >
> > The old glass and wooden stuff would go but the same
> > general size of 6" x 6"
> > would stay the same.
>
> Nothing wrong with glass plate caps for a small coil.  Such caps are not
> very efficient, but if your goal is only a few inches of spark, they are
> good enough.  Besides, they lend a cool "retro" look to a project.  Of
> course, the "Gold standard" for Tesla coil tank caps these days is a bank
> of
> small polypropylene & foil units arranged in series/parallel to achieve the
> desired capacitance & voltage rating--the so-called "multi-mini cap".
>
> > Can you tell me (on the heavy side to allow for mistakes)
> > roughly what power
> > in watts at about 45KHz (or whatever frequency you would
> > recommend) would be
> > enough for a toy like this?
>
> You only need a few 10s of watts.  Very small coils tend to have rather
> high
> operating frequencies.  500-1500kHz is far more likely than 45kHz.  The
> exact operating frequency is not at all critical.  If you wish to eliminate
> uncertainty about such things, try using one of the Tesla coil design
> programs such as WinTesla or JavaTC:
>
> http://www.classictesla.com/java/javatc.html
>
> Programs like this will tell you virtually everything about your coil
> before
> you even build it.  To heck with the "good old days" of coiling from way
> back.  Thanks in part to this list, the knowledge level is higher, the
> components & materials are better, and the resources for computer assisted
> design are just excellent.  The good old days of coiling are right now!
>
> >
> > Thanks so much, Bill Washburn
> >
>
> Best Regards,
>
> Gregory R. Hunter
> http://myweb.cableone.net/grcarhunter/
>
>
>
>
>
>
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>
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