cw sstc build advise (parameters)

[yourboi]

the new coil will be:
the coil will be on a 4.5inch tube
4awg stranded copper primary
large top load with aluminum duct
bus voltage 180v to 340v
8 parallel FGA60N65SMD in a full bridge configuration


I want to know if results like this are possible with one of those large heatsinks I see people use with a big cooling fan many times the size of an average one:

I want something similar to this if not weaker.

I also want advise to how long I should make the coil what awg I should use and how I should design the flat primary for maximum power output at my given size. I want to know if results like above are possible with my given setup. what kind of cooling and transistors would I be able to use to deal with a cw coil like this. assuming my driver has a dual flip flop for zero voltage switching operation 2 gate drivers and a Schmitt trigger with secondary feedback.

would a ferrite like this https://www.mouser.com/ProductDetail/623-5977001701 ferrite be able to drive 8 igbts?

I want to know if this build is feasible for cw operation. If not this coil will still have significant power interrupted. I want to know what theory you have on whatt zilipoper used. Do i need a PLL?

[davekni]

8 parallel FGA60N65SMD in a full bridge configuration

Should be plenty capable, of course presuming genuine parts, not Chinese counterfeits.

I want to know if results like this are possible with one of those large heatsinks I see people use with a big cooling fan many times the size of an average one:

Yes.  Heatsinks shouldn't need to be excessively large.  Use sinks with close spaced fins, not the sparse fined sinks intended for natural convection cooling.

I want something similar to this

This appears to be a low voltage high current coil compared to most.  Breakout tip on end of long handle has sodium, perhaps soda lime glass or a sodium salt.  That is what makes the arc bright yellow.  If you want bright yellow arc, you will need sodium too.

Performance for such a CW coil depends mostly on total line power available.  You can get the most power from a line circuit before tripping breaker if power factor is high.  Leaving off the bulk cap (just snubber caps on H-bridge power) allows voltage to go up and down with rectified line voltage.  Current will somewhat track, so much better power factor than when using large bus caps as are needed for an interrupted coil.  What AC line voltage and current do you have available?  You can look at Phoenix' high power version (without sodium) on his thread:
    https://highvoltageforum.net/index.php?topic=1415.msg10653#msg10653

would a ferrite like this https://www.mouser.com/ProductDetail/623-5977001701 ferrite be able to drive 8 igbts?

Depends on coil frequency and gate drive voltage.  May be a bit small.  Calculations for turn count can be found on the final post (that I just added) to my GDT tutorial thread:
    https://highvoltageforum.net/index.php?topic=1854.msg13949#msg13949

H-Bridge board construction option here:
    https://highvoltageforum.net/index.php?topic=1324.msg9795#msg9795

There is lots of other good examples on the forum.  Do some reading.  Then use JavaTC to calculate values of any design you want to try before building anything.  Try vertical primary rather than pancake.  High coupling is generally good for a CW coil.  After you have made some trial designs, then is a good time to ask detailed questions.  This forum isn't intended to design a coil for you.  Rather for you to learn and design one yourself.

[yourboi]

What AC line voltage and current do you have available?

I am currently enrolled in a tradeschool in an electricians program so whatever voltage I need can be acquired by a custom run at 120-240v USA power in my home. I also am learning the math for power factor correction which I have a 98% in the class.

High coupling is generally good for a CW coil

I intend to have a variety of interruption types to my coil with an ability to switch from filtered to unfiltered mains, with standard dc interruption and staccato interruption for the unfiltered option. you mention cw operation being ideal with a high coupling. if I am intending to also interrupt this coil should I lower the coupling? I need to rethink this whole build ill get back to posting once the driver electronics is assembled and I finished tig welding the base.

[davekni]

if I am intending to also interrupt this coil should I lower the coupling?

Probably.  Too high coupling for normal interrupted DRSSTCs can cause racing sparks.  Also depends on secondary aspect ratio.  A short fat secondary can handle higher coupling before experiencing racing sparks.

[yourboi]

Too high coupling for normal interrupted DRSSTCs can cause racing sparks

I'm intending for this to be a single resonance build.

[davekni]

I'm intending for this to be a single resonance build.

Then 0.3 coupling is likely fine, perhaps as high as 0.4.

Behavior of coil in video suggests low voltage and high current.  That may not work very well in interrupted mode.

[yourboi]

0.3 coupling is likely fine, perhaps as high as 0.4.

I made a prototype flat primary and got a coupling of .175 should I go for a spiral primary to go higher?

[davekni]

I made a prototype flat primary and got a coupling of .175 should I go for a spiral primary to go higher?

Yes, I would recommend getting to 0.3 for an SSTC.  Most SSTC designs I've seen here use a cylindrical primary, with a few conical (spiral).  DRSSTCs are mostly flat and have lower coupling, except for the QCW versions.