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Re: [TCML] Core size





--- On Mon, 4/19/10, jhowson4@xxxxxxxxxxx <jhowson4@xxxxxxxxxxx> wrote:

> From: jhowson4@xxxxxxxxxxx <jhowson4@xxxxxxxxxxx>
> Subject: [TCML] Core size
> To: "Tesla, List" <tesla@xxxxxxxxxx>
> Date: Monday, April 19, 2010, 6:58 PM
> Does any one know the equation that
> tells me the 
> power rating of a transformer core based on its dimensions
> and material. 
> 
> i am trying to figure out the power variac is rated for
> ...since it is not labeled 
> 
> i have scoured the internet to no avail...maybe i am just
> searching using the wrong terms, ... 
> 
> Thanks in advanced, 
> John "Jay" Howson IV 
I had a similar question where I have a ~48/1 step up transformer, about 80 lbs, but have no idea of its KVA rating. I recently ordered a 1 KVA 440 volt transformer. I would presume then that its primary should conduct no more then ~8.3 Amps from a secondary load since at 120 VAC input, the voltage times the amperage would be 1000 (volt- amps). I also note that with no secondary load the primary consumes ~.55 A, (at wall voltage) My next step should be to measure the unloaded primary amperage of my 10 KVA pole pig transformer. If this comes to ten times the value, or ~ 5.5 A, one would think that the KVA rating of a transformer might be determined linearly by its unloaded primary amperage, according to comparisons with other known KVA rated transformers. I wish to make a video using the 80 lb transformer showing a tesla coil with its  ferromagnetic primary being ballasted in a special way, what I have termed "resonant current ballasting."

In my first video on the subject, using the 1 KVA 440 step up transformer it was my intention to show a load that would require ballasting, and for this load I chose a small 3/8 inch width block of ferrite. Believe it or not, ferrite being a non-linear resistance will quickly heat up to incandescence at a 440 volt input and then its 1KVA primary will exceed its KVA rating, therefore to show the effect primary ballasting is necessary. I did not reach this demo on the first try as I first wanted to show the concept and schematic, and by then the ten minute limit for you tube videos had approached. Nevertheless since no one seems to understand what I am talking about when I mention a binary resonant system, in this first video on the subject I show the tuning and proof of concept. Basically inductive and capacitive reactive currents may be combined in a figure 8 tank circuit to yield the addition of both opposite reactances along a common pathway shared as
 a common line in opposite directions. I have been saying this for years, but no one seems to comprehend what I am talking about. Using this system of ballasting on a 4/1 step up transformer a 10 volt input does not yield 40 volts output before any load is added to the secondary but rather it yields over triple that amount, over 140 volts. This is shown at the beginning of the video before the unity of opposing reactive currents is demonstrated. Whether the specific arrangement here will perform well with higher KVA transformers remains to be seen.

Resonant Current Ballasting of a 1KVA 4/1 Step Up Transformer
http://www.youtube.com/watch?v=f85IUR0XEcw
This is a poor performance, but as shown the outer meters between both L1C1 and L2C2 showing .50 and .64 A sum to 1.13 A along the common reactive pathway. Both sides demonstrate the same tuning, although only the back sides tuning is shown in the video. The acting 60 hz resonant Q factor for the seriesed 500 ft spools of 14 gauge wire suffers a degradation of that factor (the ideal q factor X(L)/R = 9.3/2.6) when in the proximity of the larger ~ 20,000 ohm large induction coils. Complications evolve because one coil has a conical polar area for tighter coupling of that primary. These are basically tuned air core coils, but apparently there is not enough mutual inductance between the pairings to constantly light the neon from the secondaries side. It has been over a year since I reconstructed this circuit, and I remembered that the secondaries formerly easily lit the neon, and I was somewhat miffed that this was not occurring now so during some
 re-investigations I discovered the cause. In the next video, which the moderators are free to delete this or the entire post here as not being strictly applicable to tesla coils I made the following modification. I disconnected the back coil primary and then things worked fine,(with one further modification) Even though the back primary is disconnected, the back coil will still have amperage across it. This is the first thing that confuses folks. The reason for that occurrence is that because the ENDINGS of  the high induction coils L1C1 and C2L2 are connected in common inversely,  and when one current issues through one coil by resonant induction, it also produces current on its partner connected by common endings. In the video the back air core primary is disconnected from only one side, but when the other side is connected as a shorted loop it assumes an amperage near .25 A, where then this technically becomes a third air core resonant circuit, where
 current is induced on that coil, even though it has no direct influence from the primary itself, the dual nature of the secondaries allow this to occur. A mistake is made in these videos, a ~ 50 ma current through the 20,000  ohm  reactance coils is more like a thousand volts, rather then the stated 100 volts. Thus when both primaries are working more then sufficient voltage should be there to light the neon, but it wont, so even another reason and modification was made to achieve this.
http://www.youtube.com/watch?v=5qVLrg1iC3A

Even when the neon is directly connected across the coil under the only energized primary, it will fail to light.

I have gone on long enough about these things and since made three videos about another problem, that even shows more imbedded problems inherent with the taping of it. This is the apparent blinking of a neon to ground from the high induction coil system with a scoping of the phenomenon showing it to be 10 hz or so. Since this is not on the subject of tesla coils, write off list for those interested.

In fact the second video submitted here is also off topic, as perhaps my whole spiel here is, so I will leave it to the moderators to decide if it is noteworthy of mention.
Sincerely Harvey D Norris




      
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