high voltages

[efra_mt]

Hi everyone! Can somebody tell me how to produce high voltages (say about 15kV) from a low voltage source (less than 15VDC) and using JUST RESISTORS, CAPACITORS AND/OR INDUCTORS???. There´s any site where i can find the diagram?? Thank you very much!

 

[audioguru2]

Hi Efra,
Welcome to our forum.
Of course, the laws of physics say that you can't get something for nothing. So to make a high voltage you will need a power source, from a battery of mains transformer.

You can select a mains transformer to give you nearly any voltage.

For stepping-up a battery's voltage, you will need a charge-pump circuit (with oscillator) for a small (double the voltage) increase in voltage and a fairly low current. The charge-pump uses its oscillator to juggle capacitors.
If you want to convert a battery's voltage to a much higher voltage then you have the choice of using a switched-mode circuit (with oscillator) which produces a high voltage by taking advantage of the inductive spike in an inductor when its power source is abruptly disconnected by the oscillator. Or you can use an oscillator that feeds a step-up transformer.

As you can see, all ways of producing a high voltage involve a power source, and if AC is not supplied by a mains transformer, generating AC with an oscillator circuit. The oscillator has an IC or transistors. Passive devices such as resistors, capacitors and inductors can't produce a voltage by themselves.

 

[Yevgenip]

Audioguru is right, you can't get something from nothing. That means that if you use a transformer (which I think is the easiest) you might get a higher voltage, but in a much lower current.

Is this for projects like particle reception from space? I have some of those (schematics) if you like (from Scientific American).

Yevgeni.

P.S.
Talking about something from nothing, check this out:

let us take two equal numbers: a=b
multiply everything by a: a^2=ab
add a^2 - 2ab to both sides: a^2+a^2-2ab=ab+a^2-2ab
therefore: 2a^2-2ab=a^2-ab
and: 2(a^2-ab)=a^2-ab
devide everything by a^2-ab 2=[a^2-ab]/[a^2-ab]
then we are forced to conclude that: 2=1

is it possible?

 

[Kevin Weddle]

That is very high voltage from a DC source. I would recommend a switch mode like audioguru said. You can make one very simple. The transformer you selct will have an output current rating. This is going to be useless. But the turns ratio will give you a hint at the input current. If you have 1:2 rated at 3Arms, then you can have a primary current of 6Arms. This is equal to 8.48 Ip which gives you an average of 5.4 A. You will need a turns ratio that is much larger but this will give you an idea. The primary has an inductance that can be calculated but don't worry about that. All you have to do is make sure to get the 5.4A maximum under DC conditions. At cutoff the current should be zero. The inductance will only affect the voltage at the collector which will affect the amplitude of the output. I would saturate the transistor as opposed to not.

 

[autir]

devide everything by a^2-ab 2=[a^2-ab]/[a^2-ab]

gotcha!

 

[Yevgenip]

Yep, can't devide by 0.

 

[steven2]

today is sunday  18th of september 2005 and this article i cut out of the sunday times here in perth estern australia australia , yous might find this article intresting to say , and relates to high voltage to

View attachment 37625

 

[audioguru2]

Ridiculous!
I create more than only 30,000V of static electricity each time I comb my hair or walk across a carpet in winter.
I don't set anything on fire because the current when I touch anything grounded is so low. The few hundred pF of my body's capacitance to ground holds only a tiny charge.

Maybe if I used my static electricity to zap a grounded plate of gasoline or somethin'. :

 

[steven2]

welcome to the world of the mystery electrical phenomenas audio guru. a static charge biult up on your body from combing your hair , i thought would of been hard to measure , even with a multimeter as it wouold disharge so fast even the mioniute you grab ya meter , back in school i used to rub my shoes on the nylon carpet and generate  a charge in my body which  i discharged into the legs of the girl sitting next to me , and my nabour told me of an incedent where a fellow who wore highly static conductive clothing and generated in school a charge so big that  that he actually  threw a small ball of electrissity from his fingertips , and i read  article some years ago about a perth mechanic here in western australia , whos wife works in a synthetic cloths factory and she even wares these synthetic cloths and everytime she walks across the carpet she generates a charge so big that it even opens the gararge roller doors and would even interfear with the computer  and every time he  touches her  when he wants to get in the mood he describes it as like touching a power socket ,  as for the charge of static biult up on a comb , only so small i can pick paper up with it but cant even get a spark out of it , so wouldent you think that if a fleece jacket is made of highly static conductive matierial , much bigger than a tiny hair comb  would act as a static capacitor and hold a good charge  like that  and if the air was a bit dryer it wont leach away  so it would biuldup more when the man walks on the carpet  and if he hops into his car  which is insulated from the ground so even a car biulds up a charge as i get shocks on my mums car when i get out so  the cars that dont have the static discharge trap runing to ground under them  here just seem to act like capacitors for more static charges