Okay looking at many of the responses, I got similar feedback and it all sounds great. So here's my idea. If I drill all of the holes the same distance etc. Exactly the same, but then cut incrementally more off of each one so that I end up cutting a full spacing-between-each-coil distance off of the last one. Then when I mount them flush, each hole will be progressively closer and my primary will be nice and spirally. I AM drilling slots rather than holes.
Thanks to all who answered,
Tyler
That's how I did my latest supports, although they weren't the "through
hole" type. I routed the depression for the tubing the same on each
standoff, and just altered each block's distance from the center
incrementally by (1/n)*2d (where n= the number of standoffs, and d= the
diameter of the tubing, assuming a spacing equal to the diameter of the
tubing).
On my previous standoffs, I incremented each hole by (1/n)*2d, but it
took a lot more effort in the setup.
Jon
On 07/05/2014 09:13 AM, Derek, Extreme Electronics wrote:
>
> Or
> Make all the spokes the same and offset each spoke by 1/4 of the
> spacing from the secondary, depending of course on how you are mounting
> the spokes.
>
> Derek
>
> On 05/07/2014 16:48, Jim Lux wrote:
>> If you have 4 spokes, offset the holes by 1/4 the spacing on each on.
>> For instance, if your turns are 1" apart, the first spoke has the
>> holes at 1,2,3,4 inches, the secon at 1.25,2.25,3.25,...
>> The third at 1.5, 2.5, 3.5,
>>
>> Jim
------------------------------
Message: 2
Date: Sat, 05 Jul 2014 12:41:54 -0700
From: Krux <krux@xxxxxxxxxx>
To: Tesla Coil Mailing List <tesla@xxxxxxxxxx>
Subject: Re: [TCML] Radial Spoke Primary
Message-ID: <dbgecci2l3ar1opjfh83h8nm.1404589314771@xxxxxxxxxxxxxxxxx>
Content-Type: text/plain; charset=utf-8
You can lay them out parallel and then mark an angled line across all of them with your desired spacing. ?That should then give you your spiral. ?Try it on scrap wood first.
perl -e 's==UBER?=+y[:-o]}(;->\n{q-yp-y+k}?print:??;-p#)'
t-burns14 <t-burns14@xxxxxxxxxxx> wrote:
I'm about to drill holes in my HDPE spokes and realized that if I drill all the holes in line, I'll end up with concentric circles and then a bent piece to get to the next circle level. Not good. So how do I do this properly in order to get an actual spiral?
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------------------------------
Message: 3
Date: Sat, 5 Jul 2014 14:49:30 -0700
From: Yurtle Turtle <yurtle_t@xxxxxxxxx>
To: Tesla Coil Mailing List <tesla@xxxxxxxxxx>
Subject: Re: [TCML] Radial Spoke Primary
Message-ID:
<1404596970.57535.YahooMailNeo@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>
Content-Type: text/plain; charset=us-ascii
I had eight spokes, so I divided the center by center dimension and divided that by 8. I stacked all eight,using the offset, and cut both ends flush.
________________________________
From: t-burns14 <t-burns14@xxxxxxxxxxx>
To: tesla@xxxxxxxxxx
Sent: Saturday, July 5, 2014 7:55 AM
Subject: [TCML] Radial Spoke Primary
I'm about to drill holes in my HDPE spokes and realized that if I drill all the holes in line, I'll end up with concentric circles and then a bent piece to get to the next circle level. Not good. So how do I do this properly in order to get an actual spiral?
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------------------------------
Message: 4
Date: Sat, 5 Jul 2014 21:11:22 -0400
From: Gary Lau <glau1024@xxxxxxxxx>
To: Tesla Coil Mailing List <tesla@xxxxxxxxxx>
Subject: Re: [TCML] Radial Spoke Primary
Message-ID:
<CAKV84ba1UhOi2qF_ab=hSK=U0kn_Voc7=XrHjN398cEfCqwitg@xxxxxxxxxxxxxx>
Content-Type: text/plain; charset=ISO-8859-1
Just to be clear - you're not planning on drilling holes in the supports
and threading the tubing *through* the holes, right? Trying to thread
copper tubing through holes - even over-sized one - will make your crazy
and make a mess of the tubing. Instead, you need slots in the radial
supports, as pictured here: http://www.laushaus.com/tesla/primary.htm
Regards, Gary Lau
MA, USA
On Sat, Jul 5, 2014 at 7:55 AM, t-burns14 <t-burns14@xxxxxxxxxxx> wrote:
> I'm about to drill holes in my HDPE spokes and realized that if I drill
> all the holes in line, I'll end up with concentric circles and then a bent
> piece to get to the next circle level. Not good. So how do I do this
> properly in order to get an actual spiral?
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
>
------------------------------
Message: 5
Date: Sat, 5 Jul 2014 20:11:04 -0700
From: "Jim Mora" <wavetuner@xxxxxxxxx>
To: "'Tesla Coil Mailing List'" <tesla@xxxxxxxxxx>
Subject: [TCML] Raytheon turns ratio too high for sane resonant
charging
Message-ID: <29F32C9AB2E94B458BB58A87BDA427EF@JimonVista32>
Content-Type: text/plain; charset="us-ascii"
Hello List,
I removed the filament transformer assembly (lots of HV wires for isolation)
and the cool but way to big Inductor (150H). There is a lots of free space
in the tank assembly now. Really only the (3) HV phase voltage wires are
coming out in the centers of the HV coils into empty space on the now roomy
side. I found the star point of the HV windings on the rear. Most of that
side is close to the tank wall and LV connections. I need to revolve it
(bring the engine lift back) to address where the additional "working
windings" that were terminated near the filament transformer, also .5" HV
wire that go around to the back. The unit is very modular and a tribute to
the Raytheon engineers for serviceability and clean design. Hell, it could
have come off an old aircraft carrier. I heard it was from a missile site,
but who knows. And I won't ask... it was decommissioned and surplus sold
back on the East Coast.
Having said and done all that, it looks like I may be back to the drawing
board. I back fed 120.9 volts and measured 1.328 volts on the LV respective
phase connections with my Fluke. I may try another meter as this has not
been calibrated in a long time, just to verify like results. That gives me
120.9V/1.328V = 91 to 1 turns ratio unloaded. That would be 91T * 208 volts
wye in = 11KV! per coil, well balanced too. Even running this at half
voltage is iffy. I suppose the interaction LV voltage control with a 3P
Powerstat stack must have inductive complex relationships to the transformer
and maybe the charging coil or is that isolated by the diode strings and
dequeing?
A few things come to mind which are out of my experience level: the HV coils
are 4 individual coils in series on each core... what would happen if one or
two were removed (I know half VA rating)? These would have to be
destructively removed, not really something I want to do. Parallel pairs
like in a generator would be awesome! - 2x current .5x voltage. The theory
of possible harmonics or eddy currents is out of my league but maybe doable!
This is much like a 12 wire Gen head wired in wye in that sense.
With the turns ratio and the core dimensions I should be able to calc the ~
VA of the transformer in the ball park, yes?
Open for suggestions,
Jim Mora
------------------------------
Message: 6
Date: Sat, 5 Jul 2014 20:23:53 -0700
From: "Jim Mora" <wavetuner@xxxxxxxxx>
To: "'Tesla Coil Mailing List'" <tesla@xxxxxxxxxx>
Subject: Re: [TCML] Radial Spoke Primary
Message-ID: <67369AF0E8754D64A6DEF21B81EA8AB2@JimonVista32>
Content-Type: text/plain; charset="us-ascii"
It has been said many times here, and I can attest to feeding though holes
and having the copper become hardened and unwieldly. I tried to do this with
a 15 pitch as well and ended up cutting out the slots and cursing the
tubing. It is suggested the tubing comes out of the box and is laid down on
the coil form with as little bending as possible.
Jim Mora,
Left Coaster, USA
-----Original Message-----
From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On Behalf
Of Gary Lau
Sent: Saturday, July 05, 2014 6:11 PM
To: Tesla Coil Mailing List
Subject: Re: [TCML] Radial Spoke Primary
Just to be clear - you're not planning on drilling holes in the supports
and threading the tubing *through* the holes, right? Trying to thread
copper tubing through holes - even over-sized one - will make your crazy
and make a mess of the tubing. Instead, you need slots in the radial
supports, as pictured here: http://www.laushaus.com/tesla/primary.htm
Regards, Gary Lau
MA, USA
On Sat, Jul 5, 2014 at 7:55 AM, t-burns14 <t-burns14@xxxxxxxxxxx> wrote:
> I'm about to drill holes in my HDPE spokes and realized that if I drill
> all the holes in line, I'll end up with concentric circles and then a bent
> piece to get to the next circle level. Not good. So how do I do this
> properly in order to get an actual spiral?
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
>
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla
------------------------------
Message: 7
Date: Sat, 5 Jul 2014 23:01:43 -0700
From: "Jim Mora" <wavetuner@xxxxxxxxx>
To: "'Tesla Coil Mailing List'" <tesla@xxxxxxxxxx>
Subject: [TCML] Arithmatic error with 208v @ 90:1 transformer voltage
Message-ID: <DE690BF616CE440FBA6CFEB4E2B3F9AC@JimonVista32>
Content-Type: text/plain; charset="us-ascii"
Hi all,
I stated 208v * 91turns = 11Kv. My bad, I was experimenting with 120v in my
numbers and transposed it. The actual calculated transformer output at rated
208v input is 18,928 volts per phase! . So take 18928 * 1.41 (half wave) =
26,688 * 1.73 (fullwave) = 46,171 DC volts 6 pulse - would make a great Cap
charger with resistive current limiting! I already have one of those by
Lamda at 50Kv - too scary for me with a 16 uF 50KV discharge cap! ***Both
are 4 Sale, BTW***
Under load with (6) 8020 tube losses and the beefy 150H 564 ohm choke in
real life = 24KV. Something doesn't seem right intuitively... Maybe the
transformer core was not energized well enough to reflect real numbers on
the primary. What would be a better charging voltage into the secondary to
test this theory?
Working backwards from the name plate 24KV -out, assuming no resonate rise
we should have 24,000/ 1.73= 13873 / 1.41 = 9839 volts add losses of tubes
and inductor maybe 10k per leg? I don't get it, has to be a ratio error or
the auto-ranging on my Fluke is wacked out. I'll carefully try a higher
voltage and a different meter Sunday.
Thanks for indulging me.
Jim Mora
------------------------------
Message: 8
Date: Sun, 6 Jul 2014 10:52:27 -0400
From: Jeremy Gassmann <jeremyee78@xxxxxxxxx>
To: Tesla List <tesla@xxxxxxxxxx>
Subject: [TCML] IGBT Selection
Message-ID:
<CAKaFCg_Z-pydvYAZo7wS30Zfjbu76y0kYEKRFTedKXdECqbR+Q@xxxxxxxxxxxxxx>
Content-Type: text/plain; charset=UTF-8
Hello everyone. I am starting my journey on the DRSSTC road and have some
questions regarding the heart of the system...the IGBT. There are a lot of
options out there including half bridge packages and even full bridge
packages. Looking at the data sheets shows a lot of characteristics such as
input and output capacitance, rise and fall times, and switching energy. My
question is: what are the most important factors to look at when selecting
a device? Obviously current and voltage ratings are very important but what
about keeping capacitance as low as possible, etc? Are there any good
documents out there the correlate these parameters to an fmax of the
device?
I did find a device that looks like it would be a good candidate: the
Microsemi APTGLQ200H120G. It is a full bridge power module. Anyone work
with this device or know if there any reasons not to use it? Thank you all
very much for the help!
Jeremy
------------------------------
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End of Tesla Digest, Vol 81, Issue 6
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