Again it's not clear what you're saying. First you say "That design is fairly standard" presumably referring to flipped russian design and now you imply the opposite "to save money" aka not standard.

The only answer that makes sense is as i said that they flipped it because there is no first cap. With first cap one just needs to continue the cascade (as shown in post 28). There is no reason why second one should be flipped.

As David in first video i linked explains that output of voltage multiplier is pulsed DC on top side and steady DC on the bottom.

So, when you stack multipliers like this input on the next one is pulsating only on one terminal, other is steady DC and since second one is flipped now it's getting pulsed DC on what would normally be it's bottom side and DC on the top side. But clearly it doesn't matter as long as one side is pulsing.

It's a simple manufacturing design decision, nothing else as there is no electrically mandated standard configuration for interconnects or internal circuit connection details. Why are you so obsessed about it?

 

It's a simple manufacturing design decision, nothing else as there is no electrically mandated standard configuration for interconnects or internal circuit connection details. Why are you so obsessed about it?

I'm not obsessed, i just wanted to understand why they flipped the connections, like i said, it must be the no first cap thing.

 

The US built a large unit. This video interview with one of the builders. It is long but If you listen carefully ...

 

Between stages 1 & 2, how does + become ~ ?

View attachment 206323

When you are stacking voltage sources the positive output of one ALWAYS connects to the negative input of the next one. That is how it works. More important, it really does not matter, since the output is on top and the imput polarity is always moving back and forth.

 

Speaking of stacking voltage sources.

 

The Russian diagram is correct (bottom image of the attachment)
No need for simulation, but if you must, there is about a 1kV advantage to the Russian configuration
Note: Simulation Input 5kV 1kHz ; Output ~80kV on the Russian (bottom) ~79kV on the top

 

The Russian diagram is correct (bottom image of the attachment)
No need for simulation, but if you must, there is about a 1kV advantage to the Russian configuration
Note: Simulation Input 5kV 1kHz ; Output ~80kV on the Russian (bottom) ~79kV on the top

Great, so 5 diodes and caps are enough to increase the pp voltage 3 times, not 6 diodes and caps as usually represented.

Also, is output of your simulation steady dc? According to David it should be pulsed dc since your "ground" side is his top side.

 

There is no load, but this is what the simulator shows. Also ... a correction earlier ... The difference is closer to 10kV between the Russian version and the other version.

Keep in mind the input i used on the simulator was 5kV 1kHz ... so the pk-to-pk is actually 10kV

 

I know it's pk-to-pk 10kV, that is x3 per multiplier.

EDIT: Now i noticed the waveforms below, that is the exact opposite of what i expected. The side toward which the first diode points, bottom side in your case, should be pulsing dc. I must say that is most likely a simulation error.

 

Best video (i guess) i seen so far on voltage multiplier.

I wish someone made a vid about a tripler using only 5 diodes and caps and explained why extra diode and cap are not needed.

 

When you are stacking voltage sources the positive output of one ALWAYS connects to the negative input of the next one. That is how it works. More important, it really does not matter, since the output is on top and the imput polarity is always moving back and forth.

If you follow the positive output from stage 1 to the AC input to stage two, how does a POSITIVE source become an AC INPUT.

 

If you follow the positive output from stage 1 to the AC input to stage two, how does a POSITIVE source become an AC INPUT.

It connects to the "AC input " terminal because that is the short way to the anode of the next diode in the circuit. Circuit analysis beats arbitrary nomenclature almost every time.

 

It connects to the "AC input " terminal because that is the short way to the anode of the next diode in the circuit. Circuit analysis beats arbitrary nomenclature almost every time.

You may try to reply to my post #49.

 

Now i noticed the waveforms below, that is the exact opposite of what i expected. The side toward which the first diode points, bottom side in your case, should be pulsing dc. I must say that is most likely a simulation error.

It is not a simulation error ... To answer your question, it is relative to where the GROUND reference is on the AC source ... (See Video Link)

Note: In the video, the scope lines corespond to the two outputs on the far middle right.

Video Link:
http://www.bscircuitdesigns.com/Oklahoma Robotics/HV Multiplier.mp4

 

It is not a simulation error ... To answer your question, it is relative to where the GROUND reference is on the AC source ... (See Video Link)

Note: In the video, the scope lines corespond to the two outputs on the far middle right.

Video Link:
http://www.bscircuitdesigns.com/Oklahoma Robotics/HV Multiplier.mp4

I don't understand why changing the ground REFERENCE changes which side oscillates, nothing changes in the circle, it's just a reference.

 

I don't understand why changing the ground REFERENCE changes which side oscillates, nothing changes in the circle, it's just a reference.

It absolutely changes in the "circle" - circuit

Here is another video that systematically removes one diode and one capacitor down to the point where all you are left with is the AC voltage supply and you can see how moving the ground does make a difference and how the voltage effectively propagates through the multiplier.

http://www.bscircuitdesigns.com/Oklahoma Robotics/HV Multiplier v2.mp4

 

"to the point where all you are left with is the AC voltage supply and you can see how moving the ground does make a difference and how the voltage effectively propagates through the multiplier"

And how does that make sense? You got AC source and open circuit yet only one side (opposite to ground reference) is oscillating, how, why.

This is like connecting a dipole antenna to AC source and then say that only one side of the dipole is oscillating.

 

"to the point where all you are left with is the AC voltage supply and you can see how moving the ground does make a difference and how the voltage effectively propagates through the multiplier"

And how does that make sense? You got AC source and open circuit yet only one side (opposite to ground reference) is oscillating, how, why.

This is like connecting a dipole antenna to AC source and then say that only one side of the dipole is oscillating.

The dipole antenna has a symmetrical electrical response because the electric field is distributed symmetrically. The purpose of the multiplier is to have a asymmetrical response that separates charge creating a electric potential that stores energy between stages.

 

The dipole antenna has a symmetrical electrical response because the electric field is distributed symmetrically. The purpose of the multiplier is to have a asymmetrical response that separates charge creating a electric potential that stores energy between stages.

We are not talking about a multiplier now, but empty circuit.

 

We are not talking about a multiplier now, but empty circuit.

Why? I don't think he was talking about empty circuits.

Isn't the point of this thread to understand how variations of voltage multiplier configurations work.