Cockroft-Walton question.

Guy Macon wrote in news: snipped-for-privacy@corp.supernews.com:

This fellow is going to accidentally kill himself one day.

See, for example...

Newsgroups: alt.binaries.schematics.electronic Subject: Charge Pump (from S.E.D) - ChargePump-4X-Example.pdf Message-ID:

...Jim Thompson

Yes, that should have been 3V not 4V.

Bob Clark

Correction: with the usual circuit adding another stage takes it from

Bob Clark

Google didn't pull that one up, since Google doesn't archive binaries. Do you have another source for that?

Bob Clark

Use a good news server. Doesn't your ISP have a news server?

I designed it ;-) It's now on the S.E.D/Schematics page of my website.

...Jim Thompson

How many times does it multiply the input voltage?

Bob Clark

"ChargePump-4X-Example.pdf" 4X ?:-)

...Jim Thompson

This thread is setting some sort of record for "least coherent."

John

This is true. Rational people could explain the OP's issue using the terms "AC" and "DC," but we can't use those terms here anymore..............................

What's the puzzle? The ac swing you have available to work with and stack up, is always V, that's not doubled, or tripled, etc., at any point. That'd be nice, but how would it be?

well i meant to say 3000 V not 3000 Kv or should have said 3Kv on the input. and that is on the input side of the pie xformer. the output of the pie is around 12k..18k volts. one of the vessels is around some where in the neighborhood of

from what i have seen in here from some, it may not be an accident! :)

Cockroft-Walker multipliers with fewer components can multiply voltage

Cockroft Walton Voltage Multipliers

Are saying your circuit has the advantage of being able to be staged to *multiply* by 4 each time?

Bob Clark

"Charge pump" is a catch-all term that is also applied to Cockroft-Walton multipliers. Are you sure the type you're thinking of can be staged to *multiply* by the same factor at each stage?

Bob Clark

Read more carefully, it multiplies 8X the PEAK, or 4X the Peak-to-Peak; mine does the same, just in a fashion that allows monolithic implementation without forward biasing wells and creating latch-up, etc.

Diodes can't be implemented in monolithic form, as in your example, because all kinds of bad parasitic things happen.

You've got a hair up your butt about "staged".

"Staged" doesn't happen. The output is DC. The only way would be to add a switching device at the end of a 4X and you have no power to run it.

...Jim Thompson

The circuit that I described as a theoretical possibility that isn't used, only to discover that someone was using it, actuall does multiply.

Consider a bog-standard Cockroft-Walton voltage multiplier that has a DC-to-AC inverter on the front end, and enough levels to get a nice

Now take that 10X DC out and use it to feed another bog-standard Cockroft-Walton voltage multiplier that has a DC-to-AC inverter on the front end, and enough levels to get a nice 10X increase from the DC in to the DC out.

The downside is that doing this throws away the main advantage of the Cockroft-Walton configuration; that no component is subjected to more than a small fraction of the output voltage. A regular Cockroft-Walton can go as high as you want.

(I am still amazed that anyone would do it that way given the many alternative topologies that seem, on the face of things, to be better choices.)

You can't read what is not there. You ONLY said it multiplies "4 times". The Cockroft-Walton circuit page specifically says 8 times peak. You're post is also misleading in that it was in response to the post by "cnctut" who suggested "charge pumps" could multiply at each additional stage. I don't know if this is accurate or not.

Bob Clark

No charge pump MULTIPLIES! A better phrase would be STACKER... stacks one capacitor on top of another.

...Jim Thompson