Competition: High Voltage Power Supply

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You're picking at it again, tcm. I thought we already went through this.


Thanks for your vote of confidence, Ian. I agree with you--there are plenty of members here who could do a great job with this project if they'd just pull their heads out of their........I mean...if they'd just let go of the details and just focus on the outcome. I know the potential is here and that we've got a great group of guys/ladies who could do very well. I just wish some of them would come out of hiding and see that there's nothing to be worried about.

Best wishes,
Matt
 

If you don't have anything constructive to say, please don't say it.

The host does not have a design that manages the requirements. That's the entire purpose of this competition! He needs a circuit similar to the one in a TV, but it should be smaller, as well as have a variable voltage and current output. I have already explained that your design does not meet the criteria because it is too bulky and heavy. It's as simple as that.

Why are we still flogging a dead horse? I swear we've been over all this already....
 

Sorry John, I mistook your post for someone else's.

The problem with the instructables one is that the output can't have a variable voltage and current output. You could control the voltage using a variac, but again that would be too big and heavy for the host's needs.

As for the second circuit, I think I mentioned when you first suggested it that it would work fine if the designer modified it so it too could have a variable voltage and current output. I think that was one of the posts that I was thinking could get the whole thing off the ground.

Again, sorry for the confusion

Regards,
Matt
 
Not picking. I thought that what I had asked about what he will be doing to the bugs with HV was a legitimate question.

So to be fair can he pass 20 KV at 60 ma through a bug without it turning to flaming carbon dust?
 
Not picking. I thought that what I had asked about what he will be doing to the bugs with HV was a legitimate question.

So to be fair can he pass 20 KV at 60 ma through a bug without it turning to flaming carbon dust?

Nobody said anything about passing the current through the insect. That was your own assumption, and if you read the quote from his PM, you'll see that that is not the intent.
 
Fair enough but then what is the 60 ma requirement for? If its being produced purely as a coronal discharge that still 1200 watts of heat coming off of single electrode point.

The point is the highly vague application specs are still not making much sense to apparently a lot more people than just me.

Here is how I would have approached this whole competition.

----------------------------------------------------------
Hey everyone I would like to propose a competition to create a high voltage output device for multiple applications.

The requirements are that is should have an adjustable HV output capable of up to around 20 KV with a good corona discharge but also able to be used for producing an electric arc preferably capable up to around 60 ma if possible but able to be adjustable for less peak current limits.

The power source can be anything from a common 12 VDC source for lower power designs or a line powered source for a high powered design.

So that's it. 0 - ~20 KV adjustable output with 0 - ~60 ma current limiting function capable of running continuously in both corona discharge mode or electric arc mode.
Power source compatible with common DC voltages or AC line sources.

Thanks.
 

How is that any different? Every bit of that has been said already!

What I said to John should have been to you instead. If you don't have anything constructive to say, don't say it. I've had about enough of your picking. It hasn't had any positive impact to the thread whatsoever, and I'm about this close to asking the mods to clean it up.

To anyone who has actually helped with this thread, I thank you for sticking with it.

Regards,
Matt
 
This challenge began on January 18, 2013 with a set of specifications that would at best be very difficult to meet regardless of budget, but when considering limitations on budget, size, and weight, the goals appeared unattainable.

Those original specifications have been modified. For the purpose of clarification, here are what currently exist in Post #1 (emphasis added to certain items):

1) Supply a stable, yet variable voltage output of roughly 0-20 kilovolts, with enough current to sustain an arc rather than a series of small sparks. Adjustable current is preferable. The closer the current comes to 60mA, the better.

2) Must be able to run for 24 hours straight without damaging components or creating excessive heat (Comment: The term excessive suggests that a certain efficiency must be met. What is it?)

3) Fit on a 4x4 inch perf board, not including the flyback transformer or any external power supplies

4) Try to keep the cost under $150.00us. Includes Shipping. (To where?)

5) Focus on how you can sustain an arc 24hrs at 20k without burning things up. That's the question. If it's a Flyback design, how far would you push it? Only 1ma? So be it. If it's a NST, again, how far would you push it? The same question goes for the tripler John suggested. Also, what would be the sacrifices in order to get 20kv? These are the questions for the contestants to answer for themselves.

6) NST's (solid state type, due to their small physical size and weight) and Tripler's are allowed, provided the cost remain under $150. (Comment: The acceptablity of NST’s has changed so many times, it is not clear what is accepted. At present, are solid-state NST’s the only form allowed?)

Scoring:

These specifications are not firm, so feel free to let your mind run. Designs will not be judged based only on how much of it matches the specs. Instead, they will be judged on how well they operate, efficiency (use of space, etc), and overall design. (Comment: This is way too vague for any legitimate contest. It pretty much allows you to decide that a CFL power supply would win.)
Bonus points will be given for original designs (not pulled off google), and for designs which allow for switching between battery and mains.

Entries should be submitted no later than March 1st. The community will vote on the entries to determine the best 5, based on theory and overall design. Finally, I have been selected to build these 5 circuits and choose the best design according to the afore-mentioned guidelines.

DIALOG:

Posts #2-45 Questions, clarifications, confusion.

Post #46 (January 21, 2013)

New specifications given (my interpretations, unless quoted):
1) No neon sign transformers
2) TV flyback at <1 mA is acceptable (DerStrom8: “The original output power requirements were very rough since the host was not sure of the output specs that he really wanted. He has since specified that it simply has to operate like it would in its original TV application.”)
3) Host prefers DC output
4) Size limits without quantifying what would be too big or too heavy
5) With regard to the input, it is now stated “That is for the designer to decide.” It was previously stated it had to be 110/120 VAC mains and ability to also work off a battery was preferred.

Posts #47-60
More confusion and clarifications, but nothing definite.

Post #61
DerStrom8: “I believe voltage AND current variation is important to the host. That is one of the required criteria, though the ranges are not specific.” Comment: Compare to “preferred” in original specifications.

Posts #62-71
More discussion and rejected solutions

Post #72
A suggestion to use an automotive ignition coil. No comments by DerStrom8 on that proposal.

Post #76
Single judging criterion presented: “Recreate the original circuitry that drives the flyback in a TV, except try to shrink it down as much as possible, and make the voltage and current variable. Also try to make it able to run for extended periods without overheating.”

Post#82
“The host does not have a design that manages the requirements. That's the entire purpose of this competition! He needs a circuit similar to the one in a TV, but it should be smaller, as well as have a variable voltage and current output. I have already explained that your design does not meet the criteria because it is too bulky and heavy. It's as simple as that.

Post#84
“The problem with the instructables one is that the output can't have a variable voltage and current output. You could control the voltage using a variac, but again that would be too big and heavy for the host's needs.” (Comment: This limitation seems to conflict with the previous criterion that off-board supplies would not be considered in determining whether the project met the size and weight limitations.)

Post #89

Final post at the time of this writing.

MY CONCLUSIONS:

Putting all of the above together, and with particular regard to Post #76, I have tried to summarize the aim of this contest and judging criteria as they have evolved over the past week. There are still some uncertainties, and I have included my best guess at the resolution or a question in each case.

If these are not accurate, please restate the full and present criteria for this contest.

1) The contest is to design a driver circuit for a TV flyback supply. Anything that will produce an arc is acceptable, including a sustained current that is less than 1 mA. Open circuit voltage must be 20 KV. Once an arc is established, the sustained operating output voltage is not a criterion, so long as the arc is maintained. It must be able to operate for at least 24 hours. What is the electrode shape and size? The minimal length of starting arc and sustained arc (if different) needs to be given.

2) Voltage control (open circuit) cannot be by means of any sort of variable transformer.

3) Since voltage and current are related, it remains unclear what is meant by the criterion of having a variable current. My interpretation is that current limiting must be incorporated in the design. Please clarify, perhaps using percentages, what range of currents are required. For example, 0 to 100% is unlikely to maintain the arc. Perhaps something like a range of 2:1 (50% to 100%) would be more practical.

4) The design does not need to include measurement circuits for voltage or current. Those measurements will be made by DerStrom8 and/or the host using equipment they already have access to.

5) Those who submit do not actually have to have built their designs nor provide operational data. DerStrom8 will judge the designs based on a paper evaluation. He will then build 5 of the designs and will base the final decision on which one he likes best.

6) Cost for construction of each project is limited to $150 USD including shipping to Burlington, VT. That cost is only for components. It does not include a project box, PCB, solder, time, and other ancillaries. The shipping part is particularly confusing. How much does it cost to ship a design electronically?

7) Overall size and weight limits are still uncertain. Are they still being considered? If so, what are they?

8) Unit must run off of US household (110/120 VAC). Any requirement for powering from a battery has been removed.

Regards, John
 
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You're absolutely right John. A lot has changed, and I realize this has gotten confusing. I think the best thing to do at this point is ignore most of what's in the first post and use mostly what's in post #82.

Weight and size constraints:

This is what I've gathered, though I'll check with the host to make sure:

Weight: Should weigh less than 3 lbs. Anything heavier will be difficult to set up or move as a unit.

Size: This is fairly unclear. Earlier it was mentioned that it should be about 4" x 4", but I realize that's very small and it would be difficult to build it to fit in such a small space. I would say 8" x 10" would be better, but that might be too large for the host. I will see what he says and will edit the first post when I receive a reply.

Again, the main idea is to shrink the TV flyback circuit, make the output voltage and current variable, and make sure it can withstand long periods of operation. I think that's the main idea at this point.

Regards,
Matt
 
New criteria

Here is the simplified list of criteria for this project:

1) The design should act like the flyback driver circuitry in a normal TV application
2) Voltage output should be variable roughly 0-20 kilovolts, and current output should be variable roughly 0-(highest possible) milliamps
3) Entire design should not weigh more than 3 lbs.
4) Entire design should not exceed the size of a standard letter-size sheet of paper in the US (8 1/2" x 11")

With these new specifications, it should be a lot easier to create a design. Please disregard all previously-given criteria and focus primarily on the ones listed above.

Best of luck!
Matt
 
Matt,

Thank you for posting the new criteria. They are much clearer.

Now, to avoid exceeding the size of a sheet of paper, does that mean we have to use surface mount devices?
(Sorry, I couldn't resist. ).

John
 
Here is a link to my submission. **broken link removed**

Basic HV output 5 - 10 KV HF AC but easily converted to 20+ KV with a simple Voltage multiplier circuit or tweaks to driver circuit.

Adjustable voltage/current limiting built in but customization with additional voltage/current feedback circuit is possible.

Continuous duty running capable.

Power and control circuit board fits in space smaller than 8.5" x 11" paper.

weighs less than three pounds.

Universal line powered input or DC input. (Depends on where you tap into the power circuit.)

Comes with optional usage 8" glass plasma globe and case.

Price under $150 with customization's and add on features and base unit design pre built.

Fries/electrifies bugs, creates electric arcs, makes for cool ambiance lighting device, universal power input, pre assembled before optional customization, light weight, Hf AC output that can easily be adapted to higher voltage DC with minimal parts, very portable, highly adaptable/modifiable, and easily replaced if damaged beyond reasonable repair!
 
Matt,

Thank you for posting the new criteria. They are much clearer.

Now, to avoid exceeding the size of a sheet of paper, does that mean we have to use surface mount devices?
(Sorry, I couldn't resist. ).

John

Very funny!


Nice one tmctech. Does it have a variable voltage/current output?
 
Nice one tmctech. Does it have a variable voltage/current output?

Of the half dozen or so of them I have ever dissected they all had an intensity control pot and sound sensitivity pot built in that appeared to vary the output voltages and related currents by changing the base PWM duty cycles so in a way yes.

As for independent control of both output voltage and current I think that could be adapted into the stock intensity and sound feedback controls with a simple external secondary circuit that monitors the actual current draw occurring on input power side of the circuit to create a self regulating current feedback function using the sound circuit in addition to the stock PWM voltage/intensity control that is not drive current referenced.

In most of those plasma globes the sound control circuit is very simple and for all purposes I think it could be reconfigured into a current feedback loop circuit instead by replacing the microphone with current transducer and then inverting the signal so that as the sensed current goes up the output PWM goes down opposed to going up like the sound control circuit does now.

A little circuit reverse engineering followed by a few adaptions of the base design and a independent voltage adjustment with a feedback loop controlled current limiter should be possible with very few additional parts or extra costs.

Just my thoughts.
 

Thank you tcm, that's much more like it

Draw up a set of modified schematics and we'll accept it as an entry

Regards,
Matt
 
Anyway, if this is an arc thing, then usually the open circuit voltage is set higher. This one lamp I had, ran at 22 A and 40 V when operating. The open circuit voltage was 80 V and the ignition voltage was 40 kV. The arc moved in the bullb. There was a similar bulb that had arc stabilization and it had to be able to move the voltage quickly to maintain intensity.

There are going to be certain things in the environment that might extinguish the arc, if the environment is air. Maybe even an open door.

Yea, I agree John and I are on the same page. It just so happens that I took 3 kV HV power supply design out of a early electronics publication and did an experiment entitled "Electroculture in Radish Growth". It was an Honorable mention in a regional science fair in high school. The supply crapped out in the middle of my experiment, so i opened up a small TV and used the HV anode for the rest of the experiment. I even incorporated a key switch for safety. They key switch was made from a cabinet lock and a microswitch.

Sorry, no arcs.
 
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