DC-DC converter with floating ground

[coromonadalix]

good point  in all of it  PlainName

 

and others do complain,    the mod(s) may eventually close it down


but until then     Electrodacus will continue and never stop   

[electrodacus]

I did not changed my opinion.

Then why are you here making yet another thread on the same thing? You're not here to learn; you are here solely to get everyone else to agree with your erroneous but fixed opinion. You won't stop unless every last one says "Oh yes, you're right".

That's it. The thread serves no other purpose except for you to spout off and get agreement that you are right. But you are wrong, and since you will never accept that you will just forever be creating this very same thread again. And again. And again.

The only reason you're doing it here, now, is because you've been banned from every other respectable forum for doing the exact same thing there.

Did I made a tread on this floating GND problem ?
Yes you are correct that I'm not here specifically to learn but I do not mind if that happens in the process.
What other forum was I ever banned from ?
I do not get your problem with me. Do you agree or not with my answers to those two simple questions ?
If you do then I do not see the problem and if you do not then please state so and provide some evidence. 

[coromonadalix]

man i think we deal with a machine  loll   an AI  bot is here

"not here specifically to learn"

you talk like an advocate

im done,  you're black listed, sadly   this forums doesnt seem to provide this functionality

[electrodacus]

man i think we deal with a machine  loll   an AI  bot is here

"not here specifically to learn"

you talk like an advocate

im done,  you're black listed, sadly   this forums doesnt seem to provide this functionality

I'm being honest not an advocate.
Care to answer the two questions before you leave ?

[Simon]

Input and output currents surely are equal because all current entering through the input must exit through the output since there are no other external connections...

Maybe you meant to connect the negative terminals to ground?

I agree with you but looking to see if this is a common opinion.
I did not meant to connect the negative terminals to ground. The ground on that DC-DC converter is floating.

Then you know enough already to tell everyone the solution and quit the wind up!

[electrodacus]

Then you know enough already to tell everyone the solution and quit the wind up!

I'm terrible at expressing myself.

The original post contains a diagram that has a battery in series with a green box (anything can be in that box as long as it is not containing energy when connected) and a resistor as the load.

There are two questions
A) Is it possible for V2 to be a constant 30V
B) Is it possible for V2 to peak to 30V multiple times while V2 never drops below 5V ?

And I provided my answer to those questions
A) No
B) Yes

A lot of people seems to agree with me and some do not agree or do not want to provide an answer but ask for some proof my answers are correct.

Here you can see Zero999 agreed with me and even provided an LTspice example (simpler example than mine) still it shows V2 >> V1 intermittently.
https://www.eevblog.com/forum/chat/dc-dc-converter-with-floating-ground/msg5247495/#msg5247495
Also there you can see a description of how a more complex circuit can work but the idea is the same as in the simpler example provided by Zero999 and EPAIII

[Zero999]

My criticism wasn't that you edited your post, but lacked transparency in doing so.

Why did you ask the question if you already knew the answer? It it was a brain teaser, then you should have been upfront about it. Going from your posting history, I think many people here thought it was some sort of free energy scheme.

I'm not the smartest person here. Far from it. I'm sure many others are capable of figuring it out. Indeed many probably did, but didn't post a solution due to lack of will or time.

[IanB]

I'm not the smartest person here. Far from it. I'm sure many others are capable of figuring it out. Indeed many probably did, but didn't post a solution due to lack of will or time.

The reason most people are not responding is because he is not asking the question in good faith. It is, as Simon said, a wind up.

This thread, along with other previous ones, is just a big waste of time.

[electrodacus]

My criticism wasn't that you edited your post, but lacked transparency in doing so.

Why did you ask the question if you already knew the answer? It it was a brain teaser, then you should have been upfront about it. Going from your posting history, I think many people here thought it was some sort of free energy scheme.

I'm not the smartest person here. Far from it. I'm sure many others are capable of figuring it out. Indeed many probably did, but didn't post a solution due to lack of will or time.

Sorry for not being clear. Yes it was a brain teaser and I always mentioned that I know the answer to the question I was asking.
I think you are modest. You are sure fairly smart.
I did not asked for a solution if you agreed with my answers.
I asked for a solution if you disagreed with me on question A)

[electrodacus]

The reason most people are not responding is because he is not asking the question in good faith. It is, as Simon said, a wind up.

This thread, along with other previous ones, is just a big waste of time.

Using an analogy to prove a point is in bad faith ?

[bdunham7]

Using an analogy to prove a point is in bad faith ?

Using an analogy to explain something to someone who is learning from you--not debating you--is sometimes quite effective.  Using an analogy in an argument is like....well it doesn't work as well because you have to defend both the correctness of the example you are using and the validity of the relationship between that example and the point you are actually trying to 'prove'.  In this case your circuit is not analogous to the issue that is really on your mind.  But that doesn't matter because you will maintain that it is and now we have an additional thing to disagree over--and you've gotten nowhere.  So while not "bad faith" in all cases (although arguments using analogies certainly can be and are very commonly presented in bad faith in the legal profession IMO) they are almost always a bad idea when arguing contested matters.

[tggzzz]

My criticism wasn't that you edited your post, but lacked transparency in doing so.

Why did you ask the question if you already knew the answer? It it was a brain teaser, then you should have been upfront about it. Going from your posting history, I think many people here thought it was some sort of free energy scheme.

I'm not the smartest person here. Far from it. I'm sure many others are capable of figuring it out. Indeed many probably did, but didn't post a solution due to lack of will or time.

Sorry for not being clear. Yes it was a brain teaser and I always mentioned that I know the answer to the question I was asking.
I think you are modest. You are sure fairly smart.
I did not asked for a solution if you agreed with my answers.
I asked for a solution if you disagreed with me on question A)

Let's record that, so he can't rewrite history again.

Completely disreputable behaviour.

[electrodacus]

Using an analogy to explain something to someone who is learning from you--not debating you--is sometimes quite effective.  Using an analogy in an argument is like....well it doesn't work as well because you have to defend both the correctness of the example you are using and the validity of the relationship between that example and the point you are actually trying to 'prove'.  In this case your circuit is not analogous to the issue that is really on your mind.  But that doesn't matter because you will maintain that it is and now we have an additional thing to disagree over--and you've gotten nowhere.  So while not "bad faith" in all cases (although arguments using analogies certainly can be and are very commonly presented in bad faith in the legal profession IMO) they are almost always a bad idea when arguing contested matters.

Please just answer questions A) and B)

[electrodacus]

My criticism wasn't that you edited your post, but lacked transparency in doing so.

Why did you ask the question if you already knew the answer? It it was a brain teaser, then you should have been upfront about it. Going from your posting history, I think many people here thought it was some sort of free energy scheme.

I'm not the smartest person here. Far from it. I'm sure many others are capable of figuring it out. Indeed many probably did, but didn't post a solution due to lack of will or time.

Sorry for not being clear. Yes it was a brain teaser and I always mentioned that I know the answer to the question I was asking.
I think you are modest. You are sure fairly smart.
I did not asked for a solution if you agreed with my answers.
I asked for a solution if you disagreed with me on question A)

Let's record that, so he can't rewrite history again.

Completely disreputable behaviour.

Can I know what are you talking about ?  What will I want to rewrite there ?
Can you please answer A) and B) so that it is recorded.

[PlainName]

Can you please answer A) and B) so that it is recorded.

Recorded for what purpose? What are you hoping to achieve?

[electrodacus]

Recorded for what purpose? What are you hoping to achieve?

It was as a comedic response to him recording my answers
Whatever you say is recorded anyway by the forum.

[Andy Chee]

Please just answer questions A) and B)

Your analogy is flawed and incorrect. That's my answer.

[electrodacus]

Your analogy is flawed and incorrect. That's my answer.

The questions are not about any sort of analogy.
So you are refusing to answer this questions because you are not sure about the correct answers ?
I'm just assuming that if you where sure you will had no problem answering whatever you think this is analog to some other type of problem or not.

[EPAIII]

Yes, it may be possible to charge the series capacitor that you show and then reverse it's connections to place it is series with the battery to get a higher Voltage across the load FOR A SHORT TIME. But here's what the load will see as these processes happen, using YOUR second drawing, which I would modify.

1. First, starting with the capacitor discharged, it will look like a DC short so the load will see the full battery Voltage or +10 V.

2. As the capacitor charges that charge will show as an increasing Voltage that is bucking the battery so the load will see V2 as decreasing from +10 V down to zero or some lower number depending on how long the capacitor charging is allowed to continue.

3. Then the capacitor is reversed so it's +10 V is in series with the battery and the load sees +20 V for an instant.

4. Then the capacitor starts to discharge through the load and battery so it's Voltage decreases and the load sees a Voltage that decreases from the +20 V value back down to the +10 V value.

5. And it repeats. V2 looks something like this:

{My attachment should be HERE! But this stupid BB software does not seem to want that. I give up. It is below}

I would alter your drawing by having the battery Voltage connected to the load while the capacitor is charging. That way the half of my drawing below 10 V would become a straight line at 10 V.

But even that is NOT how I would double the Voltage to the load. I do not see any reason why a floating ground is needed in this circuit. I would use the battery Voltage to run a DC to AC converter which produces an AC Voltage. Then I would use a conventional Voltage doubler circuit (diodes and capacitors) to boost the Voltage to the 20 VDC level. This would include A GROUND connection to the battery minus terminal.

Or, BETTER YET, just use a DC to DC converter in boost mode WITH A GROUND connection to the battery minus terminal.

The "floating ground" buys you nothing in a battery powered circuit. The whole thing can float. It can float on top of 100,000 VDC if you wish and it will still work. Just turn the 100,000 VDC OFF before changing the battery.

You are correct for the case where you reverse the connection of that capacitor you can get a peak of 20V but when it will discharge it will drop to zero not to only +10V as the capacitor is reverse charged.

My question was if there is any possibility to get V2 > V1 continuously not intermittent.
And the reason I ask this is because people claim that the mechanical analog of this circuit  can have V2 > V1 continually.
I was even banned on this forum for arguing that will not be possible.

The way I drawn the example with an MPPT DC-DC converter it is possible to  have V2 in the +5V and +30V range never get to zero but still it requires that V2 drops below 10V (below V1). It can be done even as +9V to +30V but it will be impossible to keep it  above +10V (above V1) continually.

You are neglecting the battery Voltage.

And you were not clear as to the duration of the boost to +20 V. You talked about both continuously and for a brief time.

I only talked about what your second drawing suggested. I did not intend to completely rule out the possibility of a different circuit accomplishing "the impossible". I will not be so brash as to say that it is totally impossible. Just because one possible circuit does not do it, does not mean that none can.

You may want to take a course in logic.

[electrodacus]

I only talked about what your second drawing suggested. I did not intend to completely rule out the possibility of a different circuit accomplishing "the impossible". I will not be so brash as to say that it is totally impossible. Just because one possible circuit does not do it, does not mean that none can.

You may want to take a course in logic.

I specifically mentioned that you can have any circuit you want in the green box as long as there is no energy in the box (so no batteries or hamster wheels in the box).

I will actually be so brash as to say that is totally impossible.
As far as I'm aware nobody has demonstrated that conservation of energy can be broken. So it will be logic to claim that any circuit inside the box will not be able to accomplish "the impossible".  Magic is not real despite multiple claimed evidence of magic smoke