Suitable capacitors and switches? 10kV

[MrFox]

Hey all
Newbie here so if it's a stupid question please say...

I have been asked to build a device for testing materials for resistance against static electric discharge. The spec says 10kV and 4 Joules.

So 10kV and 100nF looks about the right region.

Questions:
1) What sort of caps can I use for this? Or specifically, can I run 10x 1uF 1000V in series? With balancing resistors?
2) Whats the best way to switch the impulse from the cap to the test area? I was asked to look at Hydrogen Thyrotrons but surely there's a better way? Series IGBTs? HV relays? (2A current limit?)
3) 10kV power supply - one of those neon transformers? A £400 DC-DC module? Build my own multiplier?

Thanks in advance!
Fox

[ElectroXa]

Hello!
Stupid question does not exist,

1) the best capacitors for this application is pulse film capacitor, as they can handle high pulse current ;
2) I would use a HV relay because current can't leak, and it is simple of operation (only a coil to actuate)
3) For the power supply, I suggest using a small HV transformer, and hook the output to a voltage multiplier.

Hope this helps 

[T3sl4co1l]

Does the spec give rise time and pulse width?  Does it conform to, or resemble, any existing standards e.g. IEC 61000-4-5?

Just dumping a capacitor, without any impedance controlling the waveform, is likely to give extremely destructive results!

You may also need a coupling network so as to apply it to active e.g. mains connections properly.

Calling it ESD sounds very peculiar; only surge has energy levels like this.  ESD as such is in the 10s mJ range (typically capacitors of 300 to 1500pF).

Tim

[MrFox]

The standard is similar (apparently) to:

EN 13938-2 Part 2: Determination of resistance to electrostatic energy.
STANAG 4490: Electrostatic Discharge Sensitivity Tests
MIL-STD-1751A Safety and Performance Tests for the Qualification of Explosives - Methods 1031, 1032 & 1033.

But I am struggling to find the rise and fall times or impulse duration.

Any further ideas? Thx

[Mads Barnkob]

The standard is similar (apparently) to:

EN 13938-2 Part 2: Determination of resistance to electrostatic energy.
STANAG 4490: Electrostatic Discharge Sensitivity Tests
MIL-STD-1751A Safety and Performance Tests for the Qualification of Explosives - Methods 1031, 1032 & 1033.

But I am struggling to find the rise and fall times or impulse duration.

Any further ideas? Thx

I am not familiar with that standards and are not going to read them through for you.

But if you are struggling with rise/fall time and impulse duration, look into the design of heart-stoppers (defibrillators), this must be thoroughly documented which capacitance, impedance and output choke to form the desired pulse waveform and length.

[shrad]

You can also document on blumlein lines and pulse forming networks