How to measure charging of Cockcroft Walton Multipliers?

shrinky · Nov 10, 2011

How do you measure the voltage of a cockcroft walton multiplier over time to observe the charging behavior? Does measuring with oscilloscopes discharge the capacitor hence you cant observe the charging or not?

NascentOxygen · Nov 10, 2011

The oscilloscope doesn't impose much loading on the circuit. You are wanting to observe the actual pumping up? That will be a short term transitory waveform. Using a CRO with differential inputs might be handy, if you wish to observe all waveforms around the circuit.

shrinky · Nov 11, 2011

Yeah. Ideally I'd like to see the oscillation with amplitude offset increasing as time goes on.

Right now I have a simple half wave multi stage multiplier set up. I can measure the rectification part, so the sine wave only goes to the positive and not negative, but I dont see the amplitude increase so that the dc offset is always zero essentially.

It could be my driving frequency isnt correct perhaps?

Rhetorical I guess but is it better to measure the voltage across the capacitor at the highest stage or measure the potential relative to ground.

NascentOxygen · Nov 11, 2011

shrinky said: ↑

Yeah. Ideally I'd like to see the oscillation with amplitude offset increasing as time goes on.

Well, it's a transient, so unless you have a storage CRO or a synchronised camera, you won't see it.

Right now I have a simple half wave multi stage multiplier set up. I can measure the rectification part, so the sine wave only goes to the positive and not negative, but I dont see the amplitude increase so that the dc offset is always zero essentially.

Are you saying it's not working?

It could be my driving frequency isnt correct perhaps?

It shouldn't matter.

Can you post your circuit schematic?

Rhetorical I guess but is it better to measure the voltage across the capacitor at the highest stage or measure the potential relative to ground.

Unless your driving source is floating, you can't connect the CRO across any ungrounded element.

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How to measure charging of Cockcroft Walton Multipliers?

shrinky

NascentOxygen

Staff: Mentor

shrinky

NascentOxygen

Staff: Mentor