[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: ARSG Questions

To: tesla@xxxxxxxxxx
Subject: Re: ARSG Questions
From: "Tesla list" <tesla@xxxxxxxxxx>
Date: Sat, 31 Mar 2007 19:50:15 -0600
Delivered-to: testla@xxxxxxxxxx
Delivered-to: tesla@xxxxxxxxxx
Old-return-path: <tcmlmod@xxxxxxxxxxxxx>
Resent-date: Sat, 31 Mar 2007 18:50:23 -0700 (MST)
Resent-from: tesla@xxxxxxxxxx
Resent-message-id: <FJ4_U0gNyRO.A.nDG.X_wDGB@chip1>
Resent-sender: tesla-request@xxxxxxxxxx
Original poster: Yurtle Turtle <yurtle_t@xxxxxxxxx>

I use Visio for my schematics.

While I was questioning the ability to parallel
filters, I saw that Matt D did the same on his PSU,
with the exact same filters:

http://bellsouthpwp.net/B/u/BunnyKiller/powersupply.html

The arrestor is what came with the pig when I
"chain-sawed the pole down". It should be easy enough
to test without it. Good question, since I'm feeding
my pig 280 vac. I can also remove the TVSS. I'm
upgrading my safety gaps, as their ROC is probably too
small.

As to power, I successfully ran my 4" coil with less C
but the same pig and welder combo for up to 5 kVA,
with nothing more than my sucker gap. I'm currently
running 5 - 6 kVA, so the sucker gap should be able to
handle this. I need to saw down my rsg motor supports
so I can try all four (two sets) gaps in series of the
rsg. Heck, I may also try them in parallel.

As configured, I cannot get my coil to run at any
power level using only the rsg. I need the sucker gap
in series to get smooth operation. With the sucker I'm
probably able to run up to 10 kVA, though both the rsg
and the sucker gap get HOT!

With the original gap, I got 480 bps at 3,600
synchronous. At 1,725 rpm 60 Hz, I should get around
307 bps at 80 Hz. Ideal is somewhat subjective, and
based on coil res. freq.

My problems don't occur when making rapid speed
changes in my rsg. I deliberately set my rate of
change really slow. I don't recall my settings (and am
too lazy to go down two flights of stairs) but I think
I set the vfd to take 5 seconds to go from 0 - 45 Hz.
My problems haven't been in rapid changes. Since my
safety's are so sensitive, I go easy.

Adam

--- Tesla list <tesla@xxxxxxxxxx> wrote:

> Original poster: "Barton B. Anderson"
> <bartb@xxxxxxxxxxxxxxxx>
>
> Hi Adam,
>
> Nice Schematic! So lets see, you've got 240 Vac
> 1-phase coming in to
> a 56A Powerstat double-stack (balanced) feeding 2
> filters. Looks like
> you paralleled all the filter inputs? Something I
> haven't done. You
> then have TVS's across the pig inputs and everything
> after the pig is
> mostly normal (except the arrestor which David used
> in his designs,
> most don't use). I noticed the arrestor is 18.6kV.
> Is that it's
> breakdown voltage? I wonder if the arrestor is
> giving you problems (I
> suspect you already pulled it out of the circuit
> temporarily to check).
>
> Wow, looks like you and I have an identical 3-phase
> drive system
> (although your RSG is much prettier than my own and
> your driving more
> power than I am). I do the same POT adjustment using
> the analog
> adjustment. It's been quite a while since I ran the
> coil, but I seem
> to remember 340 bps as ideal for my coil, however, I
> had more fun
> running it than paying too much attention to
> details. I just loved
> the ability to "rev it up"! That motor is new and a
> nice one
> (compared to others of identical specs I tested;
> nice tight bearings;
> I think it was a Baldor, same motor I'm running
> now). It was used
> temporarily for testing for a short period, but
> almost zero life on the motor.
>
> Is the sucker gap helping? Seems it might hinder
> performance. The
> sucker electrodes will take the full brunt of each
> RSG break and will
> likely heat up at high powers (lower power levels
> probably ok). I
> haven't had the same problem with my gap and the
> reason (IMHO) is
> that I'm running only about 5 KVA on that coil as
> limited by my wimpy
> variac ballast with deteriorating brushes. I think
> you are simply
> seeing a condition of running high power and more
> than the gap can
> take for it's size with the available break changes
> you can make at will.
>
> Unfortunately, this weekend will be spent on work
> (bread and butter
> work). I designed an H-Bridge Dual Controller for
> two 20A, 24Vdc
> motors using PID control for synchronization. All
> works well but only
> at half the frequency (optocoupler issue). So I'll
> be excluding
> myself from Tesla stuff for a couple days to deal
> with the issue. I
> had to design this in 1 week, so I threw parts at
> it, literally
> (thankfully, I chose a good controller chip;
> HIP4081A). On the down
> side, this was all schematic with zero testing as it
> was mostly
> surface mount devices. So today, I got a taste of
> what happens when
> you don't get a chance to proto the design. I was
> lucky I think as
> this is an easy problem.
>
> Ooops, sorry to ramble.
> Take care,
> Bart
>
>
>
> Tesla list wrote:
>
> >Original poster: Yurtle Turtle <yurtle_t@xxxxxxxxx>
> >
> >Hi Bart.
> >
> >I'm glad to finally have this thing up and running.
> >With very little tuning and much tweaking to go, I
> hit
> >7' on my second day, at 200 volts and around 25
> amps.
> >I've been working on this thing since 2003! I ran
> it
> >once two Halloweens ago, but had a gap meltdown:
> >
>
>http://www.hot-streamer.com/adam/bigass_coil/Meltdown.jpg
> >
> >I not only melted pvc, but solder as well.
> >
> >When I first started modeling this coil with either
> >JavaTC or FanTC, I seem to recall a minor upgrade
> was
> >requird, as my coil was a little outside the norm
> as
> >far as aspect ratio. But you got it fixed and it
> >pretty much nailed my tuning points.
> >
> >I occasionally hear my welder thumping, but never
> >noticed my pig doing so.
> >
> >Here's my rsg, before I mounted the motor I got
> from
> >you:
> >
>
>http://www.hot-streamer.com/adam/bigass_coil/srsg.jpg
> >
> >It's a 3,600 rpm 480 bps TTR srsg seen here:
> >
> >http://www.ttr.com/rotary_spark_gap.htm
> >
> >It claims to be good for 15 kVA. I got it from
> David
> >Rieben. I tried running my coil srsg style, but
> >decided to go arsg. I originally ran the srsg motor
> >with one phase of the three phase vfd, and it kinda
> >worked, but the vfd wasn't real happy with the
> phase
> >imballance. So I bought your 3 phase motor and had
> the
> >hub line bored (no turning back now) and added the
> >1725 rpm motor.
> >
>
>http://www.hot-streamer.com/adam/bigass_coil/rsg1.jpg
>
>http://www.hot-streamer.com/adam/bigass_coil/rsg2.jpg
> >
> >Excuse the poor pics, as I just took them in a dark
> >garage with no flash or tripod. Since I've heard
> >several people state that they couldn't run their
> >rsg's with both sets in series, I set mine up to
> use
> >just one set. Maybe I sould try the other set in
> >series, though I'll have to cut down my motor
> mounts
> >to accomodate the larger motor.
> >
> >As to the VFD, I have it setup with a pot which is
> >currently set for 45 - 150 Hz! It seems happiest
> (at
> >current power level) around 70 - 80 Hz. I'm
> curently
> >using five sets of two 37667's, so I have 75 nF.
> I'd
> >like to try removing 15 nF at a time, while adding
> Hz,
> >to see if adding more pri H helps my gap issues.
> >
> >Here's my schematic:
> >
>
>http://www.hot-streamer.com/adam/bigass_coil/schematic.pdf
> >
> >Adam
> >
> >--- Tesla list <tesla@xxxxxxxxxx> wrote:
> >
> > > Original poster: "Barton B. Anderson"
> > > <bartb@xxxxxxxxxxxxxxxx>
> > >
> > > Hi Adam,
> > >
> > > Glad to hear your getting the coil up and
> running
> > > with the VFD! I've
> > > read your posts at work but haven't had time at
> home
> > > or work to
> > > respond in the past few days. I originally used
> a
> > > resistor in my pig
> > > (2.5 ohm, really big 3KW resistor). My reason
> for
> > > using it was the
> > > pig would thump at high power levels. The change
> in
> > > current in the
> > > core causes the thumping and it is a very
> > > discernible audible low
> > > frequency noise. I only heard this with my 13"
> > > diameter coil, but
> > > quit using it with my smaller coils as the
> thumping
> > > was no longer
> > > there. I'm not sure this will help with your
> issues
> > > at the gap. The
> > > resistor is there to limit the speed of change
> of
> > > current in the core
> > > (slow the change down) as a fixed value. I don't
> > > realize a
> > > relationship for the gap issue. I mention this
> > > because it's probably
> > > wise to go down some other avenues first.
> > >
> > > I suspect the gap itself is the issue. I
> personally
> > > use as close a
> > > spacing as possible. I don't remember in the
> posts
> > > if you described
> > > your gap, but if not, that would maybe help (or
> > > picture would be
> > > cool!). I personally don't like a static gap in
> use
> > > with a rotary
> > > when I consider an ideal case. A static gap is a
> > > band aid for a
> > > rotary that needs to be beefed up for the power.
> > > But, due to cost and
> > > onhand components, it is often the best coarse
> of
> > > action for the time
> > > because as rotary requirements for power
> increase,
> > > the cost goes up.
> > >
> > > Anyway, I was just thinking if we could see your
> > > ARSG, than maybe
> > > something might stick out to those who have run
> into
> > > similar problems.
> > >
> > > Take care,
> > > Bart
> > >
> > > PS, are you adjusting speed with the 0-10V
> analog
> > > input or are you
> > > using presets? (just curious).
> > >
> > >
> > >
> > >
> > >
> > > Tesla list wrote:
> > >
> > > >Original poster: Yurtle Turtle
> <yurtle_t@xxxxxxxxx>
> > > >
> > > >Thanks. I just added another 30 Hz to my VDF
> setup,
> > > so
> > > >I can go from 30 to 150, with a 1725 RPM motor.
> > > That
> > > >will allow breakrates of up to 575. At current
> > > power
> > > >levels, I get better length at around 70 - 80
> Hz,
> > > >which is around 280 bps. I started this coil
> back
> > > in
> > > >2003 if I recall. While I say I've played with
> gap
> > > >spacing some, I kinda concider this weekend to
> be
> > > >first light, as I was unable to get the rsg to
> > > "keep"
> > > >the spark, as my safety gaps always took over.
> I'll
> > > >keep playing and will look for a big resistor
> to
> > > use
> > > >in line with my welder. I'vwe always read about
> > > some
> > > >folks needing resistive ballast, but I thought
> that
> > > >was just to keep their welder happy. I have two
> > > slide
> > > >chokes that I plan on using instead of my
> welder.
> > > Do
> > > >they also need the resistive ballast, or is
> this
> > > more
> > > >of a welder ballast issue?
> > > >
> > > >Adam
> > > >
> > > >--- Tesla list <tesla@xxxxxxxxxx> wrote:
> > > >
> > > > > Original poster: FutureT@xxxxxxx
> > > > >
> > > > > In a message dated 3/25/07 8:53:32 PM
> Eastern
> > > > > Standard Time,
> > > > > tesla@xxxxxxxxxx writes:
> > > > >
> > > > > >Original poster: Yurtle Turtle
> > > <yurtle_t@xxxxxxxxx>
> > > > > >
> > > > > >I've noticed a number of large coils use
> arsg's
> > > > > with
> > > > > >no problems, while others seem to need a
> static
> > > gap
> > > > > in
> > > > > >series with their arsg. Mine seems to be
> the
> > > > > latter.
> > > > > >Does anyone know why some need this and
> others
> > > > > don't?
> > > > >
> > > > >
> > > > > Adam,
> > > > >
> > > > > This is an interesting question and I think
> it's
> > > > > affected by
> > > > > various factors.  Factors such as coupling,
> > > > > ballasting,
> > > > > transformer voltage, cap value, power level,
> > > > > mechanical
> > > > > dwell time, rotary gap spacing, electrode
> speed,
> > > > > etc.,
> > > > > could affect this.
> > > > >
> > > > > With a high break rate, a small amount of
> > > ballasting
> > > > > is usually needed to obtain sufficient power
> > > > > throughput.
> > > > > This small amount of ballasting makes the
> gap
> > > appear
> > > > > more like a short to the transformer when
> the
> > > gap
> > > > > fires.
> > > > > The gap may try to power arc, or it may try
> to
> > > > > re-fire
> > > > > again while the electrodes are still aligned
> > > which
> > > > > will
> > > > > cause inefficient operation and heavy
> current
> > > draw.
> > > > > This especially true with a slow rotary
> speed
> > > and
> > > > > with
> > > > > wide diameter electrodes.  This becomes even
> > > more
> > > > > true
> > > > > when the rotary is slowed down for lower
> break
> > > > > rates.
> > > > >
> > > > > Making the gap spacing wider could possibly
> stop
> > > > > some
> > > > > of the problems above and make the static
> series
> > > gap
> > > > > un-needed.  With some coils, a very close
> gap
> > > > > spacing
> > > > > is needed to obtain steady firing.  So
> > > > > experimentation
> > > > > has to be done to find the best spacing.  In
> > > your
> > > > > case
> > > > > I see you tried various gap spacings, so
> some of
> > > the
> > > > > other
> > > > > factors above may be affecting your coil.
> > > > >
> > > > > Richard Hull used to use some resistive
> > > ballasting
> > > > > along
> > > > > with the inductive ballasting to dampen
> unwanted
> > > > > thumping
> > > > > and resonances in the power transformer at
> high
> > > > > break rates,
> > > > > with a small amount of inductive ballast.
> > > > >
> > > > > Coils with large caps running at 120 bps or
> so
> > > > > generally
> > > > > use larger amounts of inductive ballast, so
> they
> > > may
> > > > > have
> > > > > less need for a series static gap in series
> with
> > > the
> > > > > rotary.
> > > > >
> > > > > Regarding running 4 series rotary gaps, this
> > > also
> > > > > depends
> > > > > on many of the types of factors mentioned
> above,
> > > > > such
> > > > > as voltage, resonances, etc.  I think Ed
> Wingate
> > > > > uses
> > > > > 0.020" spacing or so on his 12 point series
> > > rotary
> > > > > gap on
> > > > > his magnifier.  If four rotary gaps are
> used,
> > > the
> > > > > spacing
> > > > > may need to be closer than when using 2
> gaps.
> > > For
> > > > > my
> > > > > small coils such as the TT-42, I have to run
> the
> > > > > rotary gaps
> > > > > very close with just a few thousands of an
> inch
> > > > > spacing.
> > > > > That coil uses only two series rotary gaps.
> > > > >
> > > > > I remember Bob Svangren saying that one of
> his
> > > coils
> > > > > ran well with a rotary with 6 electrodes,
> but
> > > would
> > > > > not run
> > > > > well with 8 electrodes.  I think it was
> because
> > > he
> > > > > had to
> > > > > slow the speed when using 8 electrodes, and
> it
> > > may
> > > > > have
> > > > > made the dwell time too long.  This may have
> > > caused
> > > > > re-firing of the gap while the electrodes
> were
> > > still
> > > > > aligned
> > > > > (two firings per electrode presentation).
> > > > >
> > > > > John
> > > > >
> > > > >
> > > > > >My 10" coil used this gap:
> > > > > >
> > > > >
> > > >
> > >
> >
>
>http://www.hot-streamer.com/adam/bigass_coil/srsg.jpg
> > > > > >
> > > > > >modified to use a 3 phase 1725 rpm motor
> for
> > > > > between
> > > > > >120 and 460 bps. I've tried various rsg gap
> > > > > spacings,
> > > > > >but adding a series static sucker gap makes
> it
> > > run
> > > > > >very smooth. Unfortunately, my coil is so
> loud,
> > > I
> > > > > have
> > > > > >to limit my runtimes to several hours a
> week.
> > > That
> > > > > >limits my ability to make modifications and
> try
> > > > > them
> > > > > >out, so I'm trying to leach info from folks
> who
> > > > > have
> > > > > >already figured this out.
> > > > > >
> > > > > >Has anyone had any luck running all four
> gaps
> > > in
> > > > > >series on an ASRG similar to mine?
> > > > > >How about two sets in parallel?
> > > > > >What gap spacing are most folks running on
> > > their
> > > > > ASRG?
> > > > > >For folks running a series static gap, what
> > > type,
> > > > > >number of gaps, and total spacing have you
> > > found
> > > > > work
> > > > > >best?
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > **************************************
> > > > > AOL now offers free email to everyone. Find
> out
> > > more
> > > > > about what's
> > > > > free from AOL at http://www.aol.com.
> > > > >
> > > > >
> > > > >
> > > >
> > > >
> > > >
> > > >
> > >
> >
>
>___________________________________________________________________
>
> > _________________
> > >
> > > >
> > > >Be a PS3 game guru.
> > > >Get your game face on with the latest PS3 news
> and
> > > previews at Yahoo! Games.
> > >
> >
>
>http://videogames.yahoo.com/platform?platform=120121
> > > >
> > > >
> > > >
> > > >
> > >
> > >
> > >
> > >
> > >
> >
> >
> >
> >
>
>____________________________________________________________________________________
>
> >
> >It's here! Your new message!
> >Get new email alerts with the free Yahoo! Toolbar.
>
>http://tools.search.yahoo.com/toolbar/features/mail/
> >
> >
> >
> >
>
>
>
>
>




____________________________________________________________________________________
Food fight? Enjoy some healthy debate
in the Yahoo! Answers Food & Drink Q&A.
http://answers.yahoo.com/dir/?link=list&sid=396545367
Prev by Date: Re: 1/4" copper tubing?
Next by Date: Re: GFI NST transformer
Previous by thread: Re: ARSG Questions
Next by thread: Re: ARSG Questions
Index(es):
- Date
- Thread