High Voltage pcb

[FonziDaytona]

Hi all,

I’m thinking about a new CW multiplier and considering designing a pcb for it. This would be used under oil…Do pcb traces under oil behave the same as wires/solder joints under oil, or does the surfaces of the pcb provide a place for tracking to occur (oil or not)?

This would be for an 8 stage full wave multiplier pushing -100kV.

-Matt

[Mads Barnkob]

You need to make room for physical cutouts, to avoid tracking. This is normal procedure in x-ray high voltage oil tanks where voltage multipliers and rectifiers are in the same tank.

This is a 70 kVDC full bridge rectifier board and its quite huge as you can see from my hand.


You can always add in some hobby factor derating as the service life you need and the consequences of a flash-over might not be overwhelming.

[FonziDaytona]

Oof! That may change my plans then. I have no access to any sort of machinery that can do that…Was hoping that oil would save me, but if not, will abort.

-Matt

[Mads Barnkob]

Oof! That may change my plans then. I have no access to any sort of machinery that can do that…Was hoping that oil would save me, but if not, will abort.

-Matt

No need to abort!

Just make enough room on your PCB to do cutouts, you need nothing more than a drill and saw to do that

[Twospoons]

If you get the PCB made by one of the cheap Chinese fabs then you can have all the cuts, slots or holes you want. The prices are low enough I've quit making PCBs myself, something I used to do quite a bit.  Unless I need it the same day.

[FonziDaytona]

I may sketch out what I was planning and then show it…It’s going to be a bit complicated as I’m putting poly capacitors in series for each stage. Might be pretty tight fitting trying to get traces and slots all in the right places. My 6 stage just has the capacitors all glued down to a piece of plexiglass and wired up.

-Matt