Regarding Chinese DRSSTC drivers on Ebay

[TDAF]

I found a few of these drivers on Ebay.
https://www.ebay.com/itm/NEW-Tesla-Coil-DRSSTC-SKP-Jump-Pulse-Driver-Adjustment-PDM-Power-Board/282819743017?hash=item41d95ecd29:g:2LsAAOSwoFVaZueB
https://www.ebay.com/itm/NEW-Tesla-coil-DRSSTC-SKP-Jump-pulse-Driver-Adjustment-PDM-Power-Board-/282775670593

They claim to be pulse-skip drivers
is this true?
Has anyone tested these??

[Hydron]

I think i posted somewhere about these boards (here or 4hv, or given I can't find it now, maybe on IRC).

They only have one output stage so "pulse skipping" can only be done by completely switching off the gate drive for a few cycles (causing tank energy to recycle back into the bus caps), but is definitely possible. This is different to the other pulse-skipping drivers out there, which only switch off one half bridge (causing the tank energy to freewheel through the bridge rather than go back into the bus caps). The chinese version will reduce the primary current quicker than the other version, but both should work similarly other than that.

The other thing I can tell from the picture is that there doesn't appear to be a phase lead circuit. This means that some hard switching will occur due to the delay in IGBT switching from zero crossing detection point, but possibly not enough to worry about (pre UD2.x drivers didn't have phase lead either and many people used them without problems).

I don't believe anyone has tried these - if someone does then hopefully they can be tested and documented as an alternative to the UDx drivers. The price is certainly attractive (not much more than the cost of the fiber receiver on it's own), and a CPLD design means that there is the potential to write new code for it too (HDL code for something like this should be simple enough to write from scratch if someone reverse engineers a schematic).

[Mads Barnkob]

Here is a thread where we discussed the Chinese drivers: https://highvoltageforum.net/index.php?topic=141.0