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		DAN'S HV ENDEAVORS
		SSTC #1 "Inchoate" .

News
...	6/19/2003 - I've been adding minor details/pictures/videos throughout the day. 6/18/2003 - Created this page.

Spark Pictures
...	All of these were taken with the coil running at ~180VAC half-wave rectified. I can not run the coil higher than 180 at present, or arcs develop along the primary coil form (which I now believe to be somewhat conductive.. somehow I overlooked the fact that it was black plastic when I bought it). Don't mind the plastic CD cover thing, it's just there to stop the breakout point (a nail) from falling over ;). A few more pictures. This time taken with a breakout point placed on the side of the toroid. Here are some pictures of sparks coming from 3 seperate breakout points. Not the greatest focusing, but you get the idea ;). And, for those that are interested, here is a high quality 1280x1024 version of the 4th picture, suitable for use as a desktop wallpaper, etc. (it's what I'm currently using for a wallpaper).

Spark Videos
...	All videos were compressed using DivX 5.0.3. As a result, they are extremely small (~100KB each). However, you will require the codec to view them. These videos were taken at ~180VAC half-wave rectified with a breakout point on the side of the toroid. Same setup as before, but this time with 3 breakout points.

Complete Setup Pictures
...	Here are some pictures as the coil is setup now, in my room. All of the drive electronics are encased in the wooden box below the coil. The variac is in the wooden box next to the DMM. The PVC pipe on top of the variac is my improvised 'chicken-stick' used for safely drawing arcs from the coil. Also notice the florescent lights at the base of the coil. They are an excellent demonstration of the immense RF field generated by this coil.

Primary Coil
...	Not only is this thing somewhat conductive, it is also a bit too big. I am currently looking for a better coilform, but progress is slow due to general laziness on my part ;).

Secondary Coil
...	About 1300 turns of #31 magnet wire wound around a 4.2" diameter PVC pipe. Winding length is 12.5". 280KHz resonant frequency without a topload. 210KHz with.

Toroidial Topload
...	Not the best, but it gets the job done.

TL494 Oscillator
...	This is what I am currently using to drive the coil. I'm using the push-pull outputs of the TL494, resulting in a minimum of 5% deadtime. I have not tested this yet, but the deadtime may be required when using IGBTs (the IGBTs turn on much faster than they turn off; this could lead to shoot-through). The RCA jack shown is used for audio modulation. It accepts a line level input and allows for audio to be modulated into the spark output of the SSTC. I will post more details on this eventually.

MOSFET Driver
...	This was originally intended to drive a larger load (hence the 6 total TC4421s), but has since then been scaled down.

IGBT H-Bridge
...	A bit tight, but quite functional (I just hope I never have to replace a damaged component!). Initially I had only intended to use this temporarily, but the results are quite nice, so I have little incentive to modify it. My first bridge consisted of some IRFP450As, but they failed due to poor heatsinking. This prompted me to construct a new bridge with some IGBTs (600v 75a HGTG30N60A4s) I had recently acquired through eBay. This bridge is extremely capable, and even when operating at higher power levels the heatsinks only become slightly warm. I almost expect the coil to overheat before the bridge! However, since these are IGBTs (which are quite a bit slower than MOSFETS), special dead-time considerations may be required. I am currently running at 5% dead-time thanks to the TL494's push/pull outputs. This is probably excessive, and I will investigate running at lower amounts (hopefully 0% if all goes well).

COPYRIGHT 2003 DAN STROTHER.
I will not be held responsible for any damage resulting from the use of
information contained on this site. Many of the devices presented here
can deliver potentially lethal shocks and cause severe burns.
Do not attempt to duplicate these results unless you know what you are doing.