Re: [TCML] July 4th and why not to be in a hurry

["Phillip Slawinski" <pslawinski@xxxxxxxxx>]

On Wed, Jul 9, 2008 at 8:21 PM, bartb <bartb@xxxxxxxxxxxxxxxx> wrote:

> Hi Phillip,
>
> Putting the coil closer to the wall would have done the trick also.
> Streamers would naturally go there most often. Breakout point would not help
> and not needed on this coil.
>

Well what I meant is that in this case the streamers did not go to the
nearby wall because it was easier for them to go out through the breakout
point opposite the wall.


>
> The VFD receives 1 phase 240V power and outputs 3-phase 230V power to the
> motor. The frequency is changed which changes the speed of the motor. It all
>  built in to the VFD. I simply use a small potentiometer mounted on the
> control panel to vary the analog signal and the drive takes this information
> and vary's the frequency accordingly. The PLC is the brains, but it's mainly
> for errors. The main reason I use it is that if the VFD gets an error of any
> type, the motor will either stop within 5 seconds or freewheel to a stop.
> The VFD outputs an error signal which I feed into the PLC. If there are any
> errors, it will shut down the main contactor to the coil. While I was at it,
> I threw in a deadman switch (low level signal), enable key, etc.


Very interesting setup.  Do you have images, schematics, etc available on
your Classic Tesla site?

How much did all the control circuitry cost?  I'm nearing completion [yeah
right] on my 6"  I just got some parts back from the machine shop, and I'm
going back tomorrow to get the rest of the parts.  I'm not sure how I lived
with that cardboard primary support.  The new primary supports are
beautiful, and I don't have to worry about the primary form catching on fire
or leakage current.


>
>
> Adam Minchey also runs 3-phase via VFD on his coils. One could also use a
> DC motor and simply vary the voltage for bps control.
>
>
> Take care,
> Bart
>
> Phillip Slawinski wrote:
>
>> Bart,
>>
>> I figured this is what you meant by field control, but I was not entirely
>> sure.  Would a breakout point have helped at all, or would that detract
>> from
>> the experience too much [not allowing streamers to craw all over the top
>> load].  This previous weekend when I was playing with my coil in the
>> garage
>> I was able to run the coil next to a wall that was well within the range
>> of
>> the maximum streamer length by using a breakout point.
>>
>> Very interesting coil you have there.  Certianly you have the the most
>> computerized classic coil I've heard of.  The variable frequency drive is
>> a
>> nice touch.  How do you vary the speed while the coil is running?
>>
>> On Tue, Jul 8, 2008 at 9:19 PM, bartb <bartb@xxxxxxxxxxxxxxxx> wrote:
>>
>>
>>
>>> Hi Phillip,
>>>
>>> I may not even have the term correct. But I look at "field control" (old
>>> term) as the control of how the spark is formed, where it's going, etc.
>>> Maybe spark control is a better term.
>>>
>>> Normally, the spark is single channel and moves along the toroid. It does
>>> stop and breakout elsewhere in a couple seconds, but the spark usually
>>> moves
>>> outward and down. When it moves "down", I like it to stay off the
>>> primary.
>>> This is easy to do with a smaller coil in a garage where the air is still
>>> and becomes very ionized. When outdoors however and especially in windy
>>> conditions like we had, it's difficult to control the spark channel. In
>>> the
>>> case of the July 4th runs, I eventually had to crank up power to get the
>>> sparks out and away from the primary. Most hits then went to the garage
>>> door
>>> about 8 feet away, some went down and hit the ground, and some went back
>>> and
>>> hit the primary (but far less often than the run in the video). The run
>>> in
>>> the video I was trying to play with voltage versus current keeping the
>>> power
>>> about the same, and to no good result.
>>>
>>> I smoked the brushes in the same ballast variac 2 years ago on a 4th of
>>> July night, so that is why I was trying to do what I could at a moderate
>>> power level (I didn't want to smoke the variac again). But after that
>>> run, I
>>> decided to go for it. It did much better, but I didn't run it as long.
>>> Another problem was bps. When you saw those multiple streamers, that's
>>> when
>>> I turned the bps down low (adjusting voltage and current), and then I
>>> would
>>> increase bps to see if my voltage and current swapping would help (it
>>> didn't). Normally, the coil likes about 350 to 360 bps, but I installed a
>>> new VFD the day before and didn't have it set to go past 80Hz (another
>>> hurry
>>> incident). I also use a PLC to control the main contactor, deadman
>>> switch,
>>> enable circuit, etc. Well, I lost the program in a computer that died
>>> earlier this year, so I had to rewrite the program (that was another task
>>> I
>>> had to do the day before). There were a lot of "little" things like that
>>> which got in my way, so needless to say, I started scrambling just to get
>>> the coil to function at all. And that's pretty much when it got dark, so
>>> I
>>> just left it as is. It happens from time to time. Luckily, no major
>>> damage.
>>> Although, I did burn off 2 primary ty-wraps which was an odd thing (I
>>> think
>>> this occurred from both a top load spark hit and auto-transformer action
>>> as
>>> it occurred about 10 inches past the tap point into the unused turns of
>>> which there were 3).
>>>
>>>
>>> Take care,
>>> Bart
>>>
>>> Phillip Slawinski wrote:
>>>
>>>
>>>
>>>> On Mon, Jul 7, 2008 at 7:22 PM, bartb <bartb@xxxxxxxxxxxxxxxx> wrote:
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>> Hi Phillip,
>>>>>
>>>>> Mainly, the field control was not good and the primary was under
>>>>> attack!
>>>>> That's mainly what I wanted to show.
>>>>>
>>>>>
>>>>>
>>>>>
>>>> When you say field control what exactly are you referring to?
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>> Yea, hard to see most of it as the guy taking the video was all over
>>>>> the
>>>>> place. Had I known he had a video camera, I would have had him use my
>>>>> tripod. But nonetheless, it's one thing to get a few strikes to the
>>>>> primary,
>>>>> and quite another for the primary be the main focus. Hit's like that
>>>>>  and
>>>>> that often can do damage. So I was trying to show what "not" to allow
>>>>> if
>>>>> you
>>>>> can avoid it. BTW, that secondary is a 1760 turn coil.
>>>>>
>>>>> Take care,
>>>>> Bart
>>>>>
>>>>> Phillip Slawinski wrote:
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>> It's hard to see what's wrong with the coil in this video.  I'd
>>>>>> consider
>>>>>> that a good run if my coil was running like that ;).  Of course it's
>>>>>> hard
>>>>>> to
>>>>>> see anything at all in that video.  It would have been nice if the
>>>>>> camera
>>>>>> had been fixed, and there was less zooming.
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
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>>>>>
>>>>>
>>>>>
>>>>>
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