HIGH VOLTAGE GENERATOR

Papabravo

Joined Feb 24, 2006
14,241
Here is the thing. You cannot get more power out of a circuit than you put in. So the input voltage is 14.5 to 18 Volts and you want to get say 300 Volts out. I don't see current mentioned anywhere. Let us be modest and say we want 300 Volts at 1 Ampere. That is 300 Watts of output power. Again let us be charitable and say the conversion process is 80% efficient. That means the required input power is 300 watts / 0.8 = 375 watts. Assume our input was 14.5 Volts that means we need 375 / 14.5 ≈ 25.9 Amperes. It does not matter if this is pulsed or continuous - required power is required power. Boosting a DC voltage, by any means, means reducing the available current. You can't get something for nothing.

As to how it works. There are at least two methods. One involves capacitors and the other involves inductors. What you do is run current through an inductor, shut the current off abruptly, capture the energy of the voltage spike, then wash, rinse, repeat.
 
Last edited:

AlbertHall

Joined Jun 4, 2014
10,234
Here is the thing. You cannot get more power out of a circuit than you put in. So the input voltage is 14.5 to 18 Volts and you want to get say 300 Volts out. I don't see current mentioned anywhere. Let us be modest and say we want 300 Volts at 1 Ampere. That is 300 Watts of output power. Again let us be charitable and say the conversion process is 80% efficient. That means the required input power is 300 watts / 0.8 = 375 watts. Assume our input was 14.5 Volts that means we need 375 / 14.5 ≈ 25.9 Amperes. It does not matter if this is pulsed or continuous - required power is required power. Boosting a DC voltage, by any means, means reducing the available current. You can't get something for nothing.
The high voltage is generated by the grey box, bottom right of the diagram, labelled 'voltage generator'.
 

Papabravo

Joined Feb 24, 2006
14,241
Then what is all the clap trap surrounding the "gray box"? The diagram is -- shall we say -- a bit unconventional.
In any case my comment still applies to the gray box. The original question was how do they do that?
 

Thread Starter

dadadiouffy

Joined May 4, 2020
77
let say, if I remove the voltage generator then I connect the circuit direct to 220vac with equivalent rectifier will it work?
 

AlbertHall

Joined Jun 4, 2014
10,234
Providing the intended result is to do yourself serious harm, up to and including death.
At the very least it would need an isolating tranformer.
 

Thread Starter

dadadiouffy

Joined May 4, 2020
77
With isolating transformer, I think the circuit itself, with voltage adjusting pot can increase voltage evenly high, if the transformer provide only 120v . let's assume, I use step down isolation transformer 240v/120v
 

Papabravo

Joined Feb 24, 2006
14,241
I don't know for certain if the rest of the circuit does anything at all. It's a tangled mess, more like a cartoon than anything else.
 

AlbertHall

Joined Jun 4, 2014
10,234
With isolating transformer, I think the circuit itself, with voltage adjusting pot can increase voltage evenly high, if the transformer provide only 120v . let's assume, I use step down isolation transformer 240v/120v
Using an isolating transformer, that blue MOSFET would be unable to turn the high voltage on and off, therefore no pulses.
 
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