[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
RE: [TCML] JAVATC & tuning
Hi
My first coil isn't finished yet, but I used the following method to
calculate the number of turns I had on my secondary. As I am using recycled
wire from the stator of an electronic washing machine, I had no wire data
other than direct measurement of the thickness of the wire by micrometer and
that was a bit dodgy. Instead I got an engineers' scale rule and laid it
against the secondary winding and took a photo with my digital camera. I
then put the image on my pc and zoomed it up and counted the number of turns
that coresponded to 10cm of the rule. That gave me the no of turns per cm
and based on the length of my coil, I calculated I had 999 turns. About
right!
Kiwi Newbie
-----Original Message-----
From: otmaskin5@xxxxxxx [mailto:otmaskin5@xxxxxxx]
Sent: Monday, 12 April 2010 10:34 a.m.
To: tesla@xxxxxxxxxx
Subject: Re: [TCML] JAVATC & tuning
Hi Bart, thanks for rechecking my JAVATC calc. Yeah, I had discovered I had
erroneously checked the AWG box being which was giving me the weird negative
space between turns (that was embarassing).
The reason I was came up with 1516 turns is that I input the heavy build
insulation thickness into the turns calculator. The spool I bought from
McMaster Carr said the wire diameter was 0.018 close to 0.0178 (which is
0.0159 bare wire + 0.0019 heavy build insulation) so I used the heavy build
0.0019 insulation thickness in the calculator. After getting your email, I
redid the turns calculator using single build insulation thickness (0.0011)
and came up with 1652 turns, almost exactly the turns number you came up
with.
The only thing I can conclude is that the spool was mis-labled as to the
wire diameter. It would be too much of a coincidence that, using 1650
turns, JAVATC came up up with almost exactly the number of primary turns
(19.2) as I found through trial & error tuning (19.3). So I gotta believe I
really got single build insulation and 1650 turns on my secondary. The only
times JAVATC was ever way off for me was when I entered a bad input.
I'll see if I can borrow a O-scope to verify frequency, but I think the
mystery is solved. Thanks again. Dennis Hopkinton MA
-----Original Message-----
From: bartb <bartb@xxxxxxxxxxxxxxxx>
To: Tesla Coil Mailing List <tesla@xxxxxxxxxx>
Sent: Thu, Apr 8, 2010 9:04 pm
Subject: Re: [TCML] JAVATC & tuning
Hi Dennis,
Got the specs. BTW, the mentioned value -0.30455 (sec space between turns)
is due to have the AWG checkbox checked instead of wire diameter. Try it,
you'll see.
The your turns value is off. 0.0159" is 26 awg and the winding turns
calculator shows 1650 turns (not 1516 as your specs showed). Change your
turns to 1650. At that point, Javatc shows 19.2 turns for the tuning. I'm
not sure where you go the 1516 turns from. Anyway, Fr will be about 95kHz.
Measure it and make sure it's around that to verify the numbers. Nothing
wrong with the program or your computer. ;-)
Best regards,
Bart B. Anderson
otmaskin5@xxxxxxx wrote:
> Thanks Bart. Attached are specs & JAVATC output. One odd thing I found
> that I didnt notice before is, under SECONDARY COIL OUTPUT DATA, the
> Space Between Turns (e/e) indicates -0.30455 inch. Not sure why it's
> showing a negative number. On the turns calculator I entered both "0",
> but also tried it by adding in the insulation thickness (x2). When I
> run the program, the -0.30455 doesn't change. Length of Wire output
> shows 2627.4 ft. That seems a bit off too since I had a 3000 foot
> spool & wound all but 30 ft or so. Maybe the program isn't running
> correctly on my computer? Thanks for taking a look. Dennis
>
>
>
> -----Original Message-----
> From: bartb <bartb@xxxxxxxxxxxxxxxx>
> To: Tesla Coil Mailing List <tesla@xxxxxxxxxx>
> Sent: Tue, Apr 6, 2010 10:47 pm
> Subject: Re: [TCML] JAVATC & tuning
>
>
> Hi Dennis, > > Tuning will vary a little with surroundings (external
> capacitance) depending on the items nearby and even the coils
> sensitivity to extC. 2 turns is a bit much, so I understand your
> reason to question it. I've found (and many others) that a coil runs
> better when the primary is tuned for more L. Thus, it is actually
> "detuned" as far as coil to coil oscillation is based on their
> component values and derivations. I've run as far as 13% detuned on
> the primary in the coils I've built. In your case, your also running
> high on primary inductance as indicated by "more" turns. There are two
> main reasons why this occurs: 1) spark length and it's external
> capacitance affect on the coil. 2) External objects affecting the coil
> itself. Beyond these main issues, there is also a 3rd. If the coil is
> relatively small in size, the primary L is often very small. Thus, a
> little extC can greatly affect tuning. This aspect is difficult to
> understand until you actually try it. > > In the end, what matters is
> your best spark length. Don't worry so much if a programs tuning is
> not perfect for your coil. Programs are using the best information
> they have, however, there's only so much data that a program can input
> that is practical for coilers. There is a point where more accuracy
> would require some odd measurements that most would not be up for or
> have the capabilities to do. > > I would like if you sent me your coil
> specs however. A Javatc output would be good. > > I haven't been
> checking my emails as often as I use to. I've been rather lazy with
> TCML this year. I do poke my head in now and then. I'll try to do
> better in the future. > > Very best regards, > Bart B. Anderson > >
> otmaskin5@xxxxxxx wrote: > >> Hey guys - I just built a built a 6"
> secondary & installed on my 15/60 system (replaced the old 4"
> secondary). I ran it on Sunday & like the way it's performed so far.
> I've got the static gap set conservatively at 0.12", & will gradually
> open in up as I get more confident everything is in balance & working
> the way it should be...which brings me to my question. JAVATC
> indicates optimal tuning at 17.3 primary turns. I started there but
> didn't get any sparks at all. Eventually after trial & error tuning I
> found the optimal primary tap point at 19.3 turns, 2 full turns more
> than JAVATC indicated. The coil seemed to run smooth at 19.3 turns and
> I didn't detect problems to indicate the anything was significantly
> out of tune. > >> In the past, JAVATC has always proven to be right on
> the money or within a quarter turn of where I've found the actual
> tuning point. So I'm thinking I'm doing something wrong here - 2 full
> turns seems like major difference. I've gone back, checked & confirmed
> all the inputs (physical dimensions & elevations) and I've run the
> program a few times always getting the same result - 17.3 turns. It's
> really bugging me like something's just not right. Any ideas on what
> else I might look to resolve the discrepancy? > >> Thanks for any
> ideas, Dennis Hopkinton MA >>
>>
>>
>>
>> _______________________________________________ >> Tesla mailing list
>> >> Tesla@xxxxxxxxxx >> http://www.pupman.com/mailman/listinfo/tesla
>> >> _______________________________________________ >> > Tesla mailing
>> list > Tesla@xxxxxxxxxx >
>> http://www.pupman.com/mailman/listinfo/tesla >
> > --------------------------------------------------------------------
> > ----
>
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
>
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla
__________ Information from ESET NOD32 Antivirus, version of virus signature
database 5024 (20100413) __________
The message was checked by ESET NOD32 Antivirus.
http://www.eset.com
__________ Information from ESET NOD32 Antivirus, version of virus signature
database 5025 (20100413) __________
The message was checked by ESET NOD32 Antivirus.
http://www.eset.com
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla