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High voltage DC voltage doubler? Answered

Is there any kind of high voltage voltage doubler that uses pulsed DC?
(Solid state not anything like a Marx)

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21 Replies

So that one definitely takes pulsed DC? If so will you need to attach it a certain way and which pins are which I don't quite understand what it's saying?

steveastrouk (author)2011-03-27

Well, pulsed DC is AC !!

No it isn't.

steveastrouk (author)2011-03-27

Sorry, its not often I pull rank, but as a professional electronic engineer for 30 years, I'm telling you it is, with an apparent change of origin.

Steve

Do the electrons move at the same speed?

steveastrouk (author)2011-03-27

Of course.

Out of interest, how fast do you think they're moving ?

Steve

1/3 the speed of light.

steveastrouk (author)2011-03-27

Nope. Walking speed.

Steve

Doesn't AC move a lot faster than DC?

steveastrouk (author)2011-03-28

The current does, but the charge carriers don't.

kelseymh (author)2011-03-27

As Steve said, "Wrong." Current travels due to collective motion of all the electrons in a material, not due to the direct travel of any given electron from source to drain. The electrons travel at drift velociy (look that up on Wikipedia), while the current propagates at some large fraction of c.

gmoon (author)2011-03-27

I think you're both right, Steve. I have seen older definitions that indicate it needs to alternate voltage through positive to negative ranges to be called "AC."

But a more modern defintion (and Wiki) doesn't require that to "alternate".

steveastrouk (author)2011-03-27

Its a relative thing, and thats where I am coming from. Where is your reference ? It can be anywhere, and a Fourier analysis shows harmonics, therefore its AC.

Mathematically, there isn't anything that is "DC" because it had to be switched on at some time.

Steve

gmoon (author)2011-03-27

Yeah, true in the strictest "academic debate" sense.

(Sometimes it's OK to use the same definitions that your local utility, electrician and UL use...)

steveastrouk (author)2011-03-28

Well, no, because as has already been pointed out, the doubler WILL work with what has already been called "pulsed" DC

gmoon (author)2011-03-28

Not to be argumentative, but why does denying that DC is a valid concept have anything to do with the use of "pulsed" DC?

This is all just noise to the OP.

steveastrouk (author)2011-03-28

True,sorry.

Steve

gmoon (author)2011-03-27

The difference between AC and pulsed DC is that a portion of AC has negative voltage in respect to ground (and that pulsed DC might not be a smooth sine wave).

It's not really important here, AND you'd probably want all the output to be positive anyway.

Go back to Lemonie's link. Click on the second pic (schematic)--it explicitly says pulsed DC is fine.

There's an input and an output. They share a common ground. That's all there is too it.

lemonie (author)2011-03-27

I meant like this as in "Solid state"
I'd suggest looking at Plasmana's stuff:
https://www.instructables.com/member/Plasmana/

L

ctscasemod (author)2012-09-13

Gmoon is right. AC is an alternating current, it does switch polarity, lets not over complicate. To be AC you have to go up and down 0, alternates.

DC is DC. At the ouptut of a bridge rectifier you have Pulsed DC, from 0 to the peak of the sine wave.

The fact you have noise on a pulsing DC current doesnt make it an AC. If you try to spin an induction motor with pulsed DC it will lock and vibrate, at least!