[TCML] VIDEO of variable speed vacuum fan RQ spark gap.
Phil Tuck (hvtesla)
phil at hvtesla.com
Mon Nov 9 03:17:05 MST 2009
Thanks for the video, that's a nice looking construction. I like the idea of the slots to concentrate the vacuum where it is needed. I can see the usual debate about gap losses could arise, so did you try to use less gaps than your current eight that you have now. I don't mean tap on different positions on that particular gap, but rather say a different 4 or 5 gap setup with bigger inter pipe gap spacing but still giving you the total you have now of 0.24 inch.
I recently ran a small pig at 5kva odd with a two gap static and was quiet pleased with the results. I too like the ease of a static over an SRSG (with a Freau controller) but a SRSG will always have more power throughput, *on paper* at least.
As I just happen to have a bit of thick wall 6 inch water pipe like that I will look forward to seeing the video of it working on a coil. (with more kva the better!)
From: tesla-bounces at pupman.com [mailto:tesla-bounces at pupman.com] On Behalf Of gary350 at earthlink.net
Sent: 08 November 2009 23:47
To: Tesla Coil Mailing List
Subject: [TCML] VIDEO of variable speed vacuum fan RQ spark gap.
Here is a video of the variable speed vacuum fan RQ spark gap. I threw this together very quick so it is not a very professional video but you will get the idea.
Since most people do not have a milling machine I think the best way for you folks to build this is to drill a row of 1/8" hole as close together as you can it will do the same thing as the slots that I milled in the side of the PVC pipe.
Most of the time the VSVFRQSG is running about 1/2 to 3/4 speed so it provides enough air flow to keep the spark gap cool.
Once you build it and experement a few times you will see how well it works.
When I get time I will hook it to a TC and get some video of the sparks getting longer and shorter as I change the fan speed with the variac.
>From: gary350 at earthlink.net
>Sent: Nov 8, 2009 3:54 PM
>To: Tesla Coil Mailing List <tesla at pupman.com>
>Subject: Re: [TCML] Pig based coil design.
>I can turn on my TC and measure the output sparks using a typical RQ spark gap with a 4" box fan.
>Then I can swap out the RQ gap with the 4" box fan for my variable speed vacuum fan RQ spark gap then turn on the TC. As I turn up the speed of the fan I can see the output sparks get longer and longer. When the fan reach a certain speed the sparks do not get longer. If I speed the fan up faster the sparks start to get shorter. There is a fan speed where it is very visible that the sparks have reached maximum length. I have taken measurements and the sparks are always at least 5% longer some times more.
>I have a variable speed vacuum fan spark gap on a 4" coil, 6" coil and my 10" coil. The same spark gap works on all the coils from 450 watts to 15KW.
>The output on my 10" TC is 12 foot streamers to a target. I can change the speed of the fan the output gets shorter. With the typical RQ spark gap with a 4" box fan the output is about 10" 6" so I am getting an extra 18" of output with the variable speed vacuum fan spark gap.
>I have noticed I get my best output when the humidity in the air is very low.
>I have built 2 different styles of variable speed vacuum fan spark gap and the both work fine.
>I will see if I can take some pics and upload them to photobucket and post the links here. My son has a very large pile of auto parts stacked up in from of my TC stuff that I have not used in several years. If I can get to the spark gap and connect it to a TC I might even be able to get a video and upload it to You Tube. Today I am working on the camper and tomorrow I have another project to deal with so it may be a few days before I get around to the spark gap.
>>From: Quarkster <quarkster at att.net>
>>Sent: Nov 8, 2009 12:56 PM
>>To: Tesla Coil Mailing List <tesla at pupman.com>
>>Subject: Re: [TCML] Pig based coil design.
>>1. You stated: "The variac tunes the spark gap to the exact speed to get
>> By "exact speed" you mean airflow rate, correct? There is no rotary
>>spark gap, and the only variable is the amount of air passing throiugh the
>>static spark gap?
>>2. By "12 foot arcs", you mean single arc channel or streamer, from topload
>>to some other object, and not two simultaneous six-foot arcs from each side
>>of your topload? In your photo, it looks like the coil is generating two
>>simultaneous 5-6 foot arcs from each side of the spherical topload.
>>----- Original Message -----
>>From: <gary350 at earthlink.net>
>>To: "Tesla Coil Mailing List" <tesla at pupman.com>
>>Sent: Saturday, November 07, 2009 3:05 PM
>>Subject: Re: [TCML] Pig based coil design.
>>> Ok.... what exactly are you looking for. Plans you can copy?
>>> Here is a link to my 10" coil. Secondary is 950 turns of #18 enamel
>>> coated copper wire close wound on a 10" diameter PVC pipe. Secondary coil
>>> has 3 coats of polyurthane. Primary coil flat would 1/4" copper tubing
>>> 1/2" spacing with strike rail. Variable speed vacuum fan RQ spark gap.
>>> Capacitor is .035 uf 40K volts. The coil produces 12 foot arcs on about
>>> 12KW at 14,000. volts. The variac tunes the spark gap to the exact speed
>>> to get maximum output. I can dial in about 1 extra ft of output arc
>>> length with the spark gap vacuum fan speed control.
>>> My suggestion is forget the rotary it is just a fancy over priced toy.
>>> Build a variable speed vacuum fan spark gap.
>>> I have a 15" diameter PVC pipe you can have it FREE if you come and get it
>>> in Murfreesboro TN 37129. I have a truck load of other diameter PVC pipe
>>> 6", 8" and 10" it is all free to anyone that will come and get it.
>>> -----Original Message-----
>>>>From: Travis Tabbal <travis at tabbal.net>
>>>>Sent: Nov 5, 2009 10:58 AM
>>>>To: Tesla Coil Mailing List <tesla at pupman.com>
>>>>Subject: [TCML] Pig based coil design.
>>>>I was wondering if someone had a JavaTC file they would be willing to
>>>>for a chicken based coil. I was thinking secondary diameter in the 12"-24"
>>>>range. The chicken is 14.4Kv 10KVA. The gap will be rotary, not yet
>>>>Tesla mailing list
>>>>Tesla at pupman.com
>>> Tesla mailing list
>>> Tesla at pupman.com
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>>Tesla at pupman.com
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