# How to draw power from HV rectified DC

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#### sqr-1

Joined Nov 17, 2018
1
Hi, In a current project, I'm stuck with what I think is probably simple to solve for experienced people.

If I have say 1000W, 3500V DC output from a fullbridge rectifier, how can I build a very simple device/circuit to utilize all or most available power virtually instantly or very quickly? A short circuit is overkill. A HV lightbulb maybe if one exists. Or a spark gap to earth is that possible? Is there some simple, cheap coil/capacitor type system (or anything else) that can quickly draw and use up the power?

I'm a hobbyist so don't know quite where to start with this part of my project.

Any and all answers appreciated. Except granny responses not needed.
Thanks

#### LesJones

Joined Jan 8, 2017
2,524
You can't use power in a finite amount of time. Power is a rate of flow of energy. So your 1000 watts is 1000 joules per second. (Joules is a unit of energy.) You need to explain exactly what you are trying to do. It sounds like you want to use a finite amount of energy in a short time so that you would have a large amount of power for a short time. So if you have 1000 joules of energy you can have 1 watt for 1000 seconds or 1000 watts for 1 second or a megawatt for one millisecond.

Les

#### recklessrog

Joined May 23, 2013
985
Hi, In a current project, I'm stuck with what I think is probably simple to solve for experienced people.

If I have say 1000W, 3500V DC output from a fullbridge rectifier, how can I build a very simple device/circuit to utilize all or most available power virtually instantly or very quickly? A short circuit is overkill. A HV lightbulb maybe if one exists. Or a spark gap to earth is that possible? Is there some simple, cheap coil/capacitor type system (or anything else) that can quickly draw and use up the power?

I'm a hobbyist so don't know quite where to start with this part of my project.

Any and all answers appreciated. Except granny responses not needed.
Thanks
By "granny responses" I guess you are arrogant enough to not take advice from those who have immense experience on the subject of working with high voltages and of the dangers that can kill you in an instant. I courteously suggest that if you are not sufficiently knowledgeable on the subject, that you do seek advice on safety, or desist before you potentially kill yourself.
Guess having survived to the age of 70 despite many years of working with high and very high voltages any advice I may be able to impart would put me in your "granny" (grandad ?) category. I wish you luck, you're gonna need it!

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#### spinnaker

Joined Oct 29, 2009
7,837
By "granny responses" I guess you are arrogant enough to not take advice from those who have immense experience on the subject of working with high voltages and of the dangers that can kill you in an instant. I courteously suggest that if you are not sufficiently knowledgeable on the subject, that you do seek advice on safety, or desist before you potentially kill yourself.
Guess having survived to the age of 70 despite many years of working with high and very high voltages any advice I may be able to impart would put me in your "granny" (grandad ?) category. I wish you luck, you're gonna need it!

I like when people ask for advice form "experienced people" but are only willing to accept the advice they deem worthy.

Why in the hell are you (referring to the TS and and similar comments) asking in the first place if you know so much?

#### recklessrog

Joined May 23, 2013
985
Something that is often not realised by thread starters, is that the questions they pose and the answers received are open to a very wide audience of people who's skills range from absolute beginners to experts. They may not be aware that this is not a "one to one" exchange of information, (that is what personal messages are for)
As the experienced forum members are aware of this, they have a duty to include where appropriate, any warnings regarding safety or potential hazards in any responses they may make.
Without doing so, even when replying to a post from another experienced member, A seed of interest my be sparked in the mind of someone without any real experience who thinks "WOW! that sounds great, I'll try that" and therefore unknowingly put themselves in danger.
You only have to look at the crazy escapades on YouTube to see many examples of " a little knowledge is a dangerous thing"

To the original thread starter I would say this, we contribute what we can to this forum for free to HELP others. We do not wish to stifle your projects or put you down. But your comment regarding "granny responses" is somewhat insulting to those of use willing and able to help, and in many cases would mean that some more enlightened members will not respond to your question because of the perceived arrogance by you making such a comment.

P.S. Whilst I have many qualifications and many years experience in various branches of electronics, and have certain expertise in some areas, I do not assume to be "expert" I know what I know, and what I don't, I'm never to proud to ask for help from others on here who may be able to enlighten me.

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#### ericgibbs

Joined Jan 29, 2010
9,574
Mod Note:
Topic contravenes AAC User Terms and Conditions.
In the interests of Safety the Thread is Closed.
E

#### bertus

Joined Apr 5, 2008
20,330
Hello,

The project you are mentioning falls in the highest safety classes according to the attached PDF.