Understanding Capacitors on SSTC

[werd]

I've been looking at a lot of SSTC schematics, and there is one thing that seems to vary between schematics that I don't understand:
Some Tesla Coils seem to have a large bus capacitor in parallel with the rectified AC along with two capacitors in series which discharge through the primary. I've seen other coils that exclude the bus capacitor and only use the series capacitors (see examples below). I was wondering if I'm either misreading the schematics or if there are reasons as to why you may or may not want the extra bus capacitor.

Thanks for the help!

Schematics with Large Bus Capacitor + 2 Series Capacitors
https://www.stevehv.4hv.org/SSTC5/miniSSTCsch3.JPG
https://www.loneoceans.com/labs/sstc3/schema_sstc3v1complete.jpg

Schematics with only 2 Series Capacitors
https://www.stevehv.4hv.org/SSTC1/FBSSTCsch3.gif
https://www.loneoceans.com/labs/sstc2/sstc2schematicv10.jpg

[Zipdox]

If you look at the schematic without a bus cap, you can see that it only has one rectifier diode. This coil is designed to run only at half of the mains cycle. It's effectively 50/60Hz interrupted.

[Mads Barnkob]

Read about the DC blocking capacitor here: http://kaizerpowerelectronics.dk/tesla-coils/sstc-design-guide/