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DC-DC converter with floating ground
magic:
--- Quote from: electrodacus on December 28, 2023, 10:39:32 pm ---a) V1 is always 10V (battery voltage).
b) V2 can be made to fluctuate between 5V and 30V using just that green box with only two wires connected to it. There is no battery in the box but there are multiple capacitors, inductors, mosfets and even a micro controller.
Is your claim that is not possible ?
--- End quote ---
--- Quote from: electrodacus on December 28, 2023, 10:43:01 pm ---Is it possible to have the V2 fluctuating between 5V and 30V ?
If not why ?
--- End quote ---
--- Quote from: electrodacus on December 29, 2023, 12:54:51 am ---Do you have an answer to this problem ?
--- End quote ---
Is it possible that you have a brain and could start using the answers people posted to solve your trivial problems? :P
Or is this some sort of democracy where truth is established by a majority vote? :-DD
electrodacus:
--- Quote from: magic on December 29, 2023, 04:01:20 am ---Is it possible that you have a brain and could start using the answers people posted to solve your trivial problems? :P
Or is this some sort of democracy where truth is established by a majority vote? :-DD
--- End quote ---
It is a physics problem and this is a sort of survey.
You say the problem is trivial and maybe it is for you but based on other comments it does not seem to be trivial.
I will love to know your answer. I gave mine in the original post.
boB:
How about an LTspice simulation of one of the answers ?
electrodacus:
--- Quote from: boB on December 29, 2023, 04:44:19 am ---
How about an LTspice simulation of one of the answers ?
--- End quote ---
Is this a question directed to me ?
There are two questions A) and B) in the original post with my answers in bold No and Yes.
A) Is it possible for V2 to be a constant 30V? No
B) Is it possible for V2 to peak to 30V multiple times while V2 never drops below 5V ? Yes
So do you not agree with one of my answers ? Or with both ?
If you say Yes to question A) the it will be you that will need to prove that as I can just use an empty box or a wire between the two points and made my case.
If you say No to second question I can describe to you how it will work but the diagram I offered as an example should be sufficient.
The capacitor will be disconnected from the two box terminals and connected to the output of a DC-DC boost converter.
The boost converter can be a max power point so one that maintain a constant voltage at the input and takes what is available.
So say DC-DC MPPT is set to 5V then the other 5V will drop across the 100Ohm resistor meaning 50mA will flow trough the circuit.
5V * 50mA = 0.25W are available with say a 70% efficient DC-DC converter 0.175W are available to charge a large electrolytic capacitor connected at the output of this DC-DC converter.
When this capacitor gets to 20V some analog trip circuit can disconnect the DC-DC and connect the capacitor between the two connection points on the green box.
Thus for a short moment V2 = 10V + 20V = 30V
It can get way more complicated than this with a microcontroller and current measurement to calculate exactly what the resistance value is and what the battery voltage is but this are unnecessary complications just to say that it can be done.
Andy Chee:
--- Quote from: electrodacus on December 29, 2023, 05:24:17 am ---So do you not agree with one of my answers ? Or with both ?
--- End quote ---
In order to resolve disagreement, we need proof. Ltspice simulation can be used as proof.
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