Xray transformer under oil

. zondag 29 april 2012
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Have been busy with the Xray transformer.
It's under oil now, the outgassing with vacuum took some time, lot's of bubbles :)

I tested the transoformer with 10V input, output was about 700V, I expected more, but maybe it's not that linear at low input voltages.

Negative HV supply for PMT's

. dinsdag 10 april 2012
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The idea of making a high voltage with a DC-DC converter and a voltage multiplier can also be used to generate a negative supply for PMT's:

There is no need to use a P-channel mosfet, just reversing the diodes in the voltage multiplier reverses the polarity of the output.
The feedback circuit needs to be adapted to a negative output, when the PCB's for the positive supply are in, I will extend the design and make one ciruit board which can generate -3kV...+3kV with jumpers to switch polarity (changing in and out of the voltage multiplier and changing the feedback circuit).

10mm polycarbonate for the 85000V supply

. zaterdag 7 april 2012
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Have been working on the (very small..) saw table today, sawing some polycarbonate sheet for the high voltage supply:

It's big enough for the Xray transformer which is going to be immersed in transformer oil (the real thing, 60kV/mm), to get the air out I will use vacuum, which will create a force of about 2900N on the biggest sides. The sides will be glued together with epoxy, the edges are 45 degrees.

I also got a preview of the circuit board for the neutron counter power supply (eurocircuits.nl):

Circuit board voor HV supply

. dinsdag 3 april 2012
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The SNM-10 and another detector tube need about 1600V.
This is the circuit board:

Designed with Eagle.
The circuit is VERY DANGEROUS, it can deliver a few milliamps at 3kV, the capacitors are charged at 3kV. If you build this thing, make sure that you know what you are doing!
Eagle BRD file
Eagle SCH file