I know this will sound stupid but...

You can't unless some switching is involved.

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Dirk

http://www.onetribe.me.uk - The UK\'s only occult talk show
Presented by Dirk Bruere and Marc Power on ResonanceFM 104.4 
http://www.resonancefm.com

104.4

ok, so could you explain this in lay man's terms?

Ok, You need to give more information.

"more voltage" means what ??

Are you looking at getting 100 volts from 12v DC.

Are you looking at getting 12 v DC at a special load. ( only known by you)

Are you looking at doing a homework assignment only known by your professor ?

If you want an complete answer, ask a complete question.

What do you expect ??

Mind reading ??

donald

what you are looking to build is called an "inverter" (AC output) or "boost converter" (DC output) -- it takes the DC input, and using transistors or mosfets and an oscilator, turns this in to AC.. which is then run through a transformer to get your desired output voltage... if you want DC out, the voltage is then rectified and filtered. (this is grossly over-simplified, but depending on what you are trying to do, some of the circuits are pretty simple !!)

just hooking caps across a DC supply will charge the capacitors then do nothing (unless the DC supply is too much for the caps, in which case they go BANG !!)

what capacitors in a circuit do is store charge so that momentary surges in demand can be handled without dramatically pulling down the voltage..

Cough up a bit more about what you are trying to do and we'll see about finding you some schematics or at least some theory sites to get you up to speed :)

A fixed addition "consisting of capacitors" (to quote part of the question) will not (by themselves) increase the voltage of a 12 volt DC supply.

If you could post a more complete question about what you are trying achieve; using what kind of circuit etc. you may get some guidance. There may be suitable circuit configurations where the placement or addition of certain capacitors could influence the voltage of the output of a voltage supply.

Various half-wave, full wave, voltage doubler circuits etc. are described in many text-books. But will involve more than just capacitors.

In other words there are a whole host of 'what if' and 'what type of' questions that could be asked; but that's just a guessing game!

A 'trick' answer to your question could be as follows;

If I charged up two identical capacitors each to 12 volts and then connected them in series they would just for a few moments (depending on the size of the caps. and whatever was measuring and discharging them) would as the as the voltages decayed, add the two voltages together.

which would rapidly die away to zero as the caps. discharged.

The question is so vague that it's rather like asking "If I put 12 gallons of water into a leaky bucket how long would it take the water to drain out?'.

if you have access to the AC part you make a Cockroft-Walton or similar charge pump circuit.

Bye. Jasen

104.4

The obvious way to do it is to charge a whole load of caps in parallel and then put them in series. However, it's normally done with an inductor charging and then being disconnected from its supply, whereupon the voltage rises to the desired level and is tapped off. This is done thousands (millions?) of times a second for a smooth flow using transistor switching.

Not trivial from your POV.

--
Dirk

http://www.onetribe.me.uk - The UK\'s only occult talk show
Presented by Dirk Bruere and Marc Power on ResonanceFM 104.4 
http://www.resonancefm.com

Ok to all of those who want to know more about what I'm doing: I'm trying to make a high voltage electrolosys machine ( to split wanter into its 2 elemental forms hydrogen and oxygen.) Higher voltage= faster spliting.

EDIT: I want the voltage to around 150-200...

Really? I would have thought the voltage was self limiting and higher current = more output.

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OK -- that means DC current -- what is your intended source of power ?? batteries ?? wall juice ??

I just did some double checking -- what I'm reading is that lower voltages (1.6-2 volts) and higher currents are what you really want (on the order of

10s to 100s of amps) (reference: ) .... More voltage can help, but its really the current doing the work. Higher voltages help when you are electolysising more "difficult" chemicals.. water is an "easy" one !! Especially Deionized water when mixed with sulfuric acid.

So what you really want is a current mode buck converter designed for extreme high current output. Current mode means the current is regulated, and the voltage goes where it needs to based on the resistance of the load (with in the maximum limits based on the design of the converter). What this does for you is get you those high current densities needed, and the voltage will automatically adjust to the solution being processed... here is the trick -- if you use deionized water and sulfuric acid.. you adjust the voltage by adding one or the other, not by messing with the power supply... adding more DI will increase the voltage and reduce the current (until you hit the voltage limit), adding more acid will decrease the voltage and increase the current (until you hit the current limit), which will help you keep your solution in balance once you determine the proper ratios for most efficient gas production.

OK -- here is the problem with the idea of boosting a 12v supply up that high... boost converters basically act like electronic transformers -- so approximatly watts in = watts out (minus losses).... so -- to create 120v at

1 amp from 12 volts takes 10 amps + a little current.. to get voltages like that you are much better off starting with wall juice, which is correspondingly more dangerous to work with.

Here is the real danger.. for a given solution being processed, the solution has a resistance.. let us say for instance the resistance is 1 ohm... at 12 volts, a 1 ohm resistance will consume 12 amps of current... however, as 120 volts, it will consume 120 amps (rather more than enough to blow any breaker in your panel !! and blow you across the room if you get in the way !!)

This gets into what I described in my other post.. if you use Deionized water and sulfuric acid, you will have some control over the resistance of the solution, and can therefore balance the voltage and current.

A-f****ng-mazing.

You want hydrogen and oxygen, you do not want "more voltage".

A-f****ng-mazing.

.... More voltage can help,

my intened source of power was bateries because it needs to be portable

And how would u build 1 of those "current mode buck converter "?

How many grams of each gas do you want?

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I just realized I didnt go far enough on part of the explanation above.

if you start with a 1 ohm soulution... and hit it with 12 volts, that will take 12 amps. (144 watts) then use a booster to hit the solution with 120v , which will take 120 amps (14400 watts 14.4 KILOWATTS) BUT since the booster is running from 12 volts, . it will consume more than

1200 AMPS to generate that 120 volts at 120 amps

I have some big gel cell batteries that come out of the power backup systems for cell phone towers -- they are rated at 100 amp/hours, and setting up 120 of those or more to power the booster would be something of a challenge !! and even then, they wouldnt run the system for very long (120 batteries = 1 hour of run time !!)

Now -- those same 120 batteries -- if you adjusted the resistance of the solution, could dump the same amount of power (14400 watts) in the same amount of time (1 hour) resulting in close to the same amount of gas produced as the 120v system (it takes 4 kwh (kilowatt/hours) to produce 1 cubic meter of hydrogen pretty much no matter what your voltage/current ratio is)

which brings up an interesting note -- all that power from all those batteries will create around 3.5 cubic meters of hydrogen

if you really want to run up the production rate -- we need to talk wall juice !!

Switching will be fun too.

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