Hi everyone, welcome to Hack Chat! I'm Dan, I'll be the mod today as Jay Bowles takes us Into the Plasmaverse.
I know he was planning on doing this during his lunch break, which we really appreciate. But I haven't seen him log on yet - you out there, Jay?
There we go. Hi Jay!
Hi Dan, sorry for the wait. My internet had plans of its own!
I am free for a full hour, for any questions related to high voltage physics!
No worries, thanks for soldiering through. Can you kick things off with a little about yourself?
I'd be glad to. I live in Seattle (just outside of it) and am the host of Plasma Channel, a youtube channel dedicated to high voltage physics, ionic physics, and just about anything lightning related. I've had this passion since I made my first tesla coil when I was 15. Funny story - I made a big tesla coil and used it for my high school senior project. When I turned it on in my physics class, nearly lost their heads.
I firmly believe that through physics, all things are possible. High Voltage physics, in particular, is pure magic. Let me show you the magic I see! This cha...
You didn't fry anyone, did you?
Since then, I have moved quite a bit, but constantly help experimenting and committing fully to self discovery.
Have you explored keV? like acclerate eletrons in vacuum?
Seems like a skipped field, I would have.. but I don't have the tools for doing anything interesting
Erlend, that is a great question. It is a topic I plan on intesting in soon. I'm purchasing vacuum equipment this month.
investing in soon*. The limitation for me has always been vacuum chambers and a lack of experience with glasswork
b.t.w. need any negative output voltage "TV" flybacks?
I never turn down a good flyback. They are thor's gift to the world
Speaking of those, where would be the best place to scrounge one?
Truly hard to find, are AC flyback transformers though. They do exist! I found that a few higher end brands of ionic air purifiers use AC flybacks, attached to an external voltage multiplier (inside the device)
Well, I am a strong advocate for goodwill.
I find so many of my flybacks at goodwill for 3-5 dollars. The little ones you can find inside of portable battery powered glass-tube TV's.
Woe to the death of CRT monitors and TVs. Flybacks were once in abundance
Jay: Well, I got a HV supply I should probably take a chance at trying to boot up, and fix some PCB design flaws
AC flybacks are still in production for things like CO2 lasers. They show up on ebay. But sure old B&W monitors or oscilloscopes are a good bet too.
And yes, got one positive output flyback and one negative output flyback on it
You can also successfully wind your own as well.
So, old CRT are the best place for HV parts?
Unless you can get physics lab stuff, I would guess it is
You can find new parts online. Like the link I provided above. They are very, very cheap.
You can still find some manufacturers online, and you can ask them to do variations for you
I personally prefer the adventure of taking apart devices to extract their HV components. You learn about devices and circuits that way.
What about old ignition coils? I used to have fun with those back in my Volkswagen phase. Any good for HV circuits?
I believe Pacific Transformer Co even sends out free samples of custom transformers (if you can prove you've got the funding to order some later)
Ignition coils I LOVE. but I also hate them. Anyone able to guess why ignition coils kind of are hard to drive?
ignition coils? they do claim 30-50 kV on them.. there are solid plastic ones that would likely be good
Jay: You may want a capacitor over the primary,or the transistor gets it
They put out plenty of voltage and current....but on the primary side they also put out.... (finish this sentence)
(Blueprint walks in, looks around, takes a seat)
Jay: high voltage on primary too yes, ignition coils are auto-transformers, while flybacks are isolated
Erlend, that is the funny thing. I have tried all types of snubber circuits to prevent the emf kickback on an ignition coil. I found the better the snubber circuit, the more it detracts from the HV output of the ignition coil
To be expected to be honest, I would suggest going for avalanche mosfets
My 555 timer circuit, despite a snubber circuit with cap and resistor, blows through 555 timers and transistors incredibly fast.
They would conduct on overvoltage, without destruction
Or just do NOT run them with a open output
Well then, you just need to mechanically pulse the primary side just like an old distributor. Points and condenser FTW
There in lies the issue. Overvotlage of the primary is inevitable, and HV output is dependent on it. So, when you suppress overvoltage of the primary....the output flat out sucks
Correct. However...where is the fun that?!
Even, I did a driver with a horizontal output transistor from a monitor, it killed the coil
Wow. I've never had a coil fail on me. You must have really powered that beast
That would actually be cool, an electric motor driving an old distributor.
Interesting. Using the distributor as a relay?
Jay: 1200V avalanche motfet if you can find it.. but it's likely to get hot on open output
Ideally, you would want feedback, but that's easier on DC
I'm all for strength of components. It's why I cant stand IC's.
Sort of. Just have the points open and close as the cam rotates.
If you are into figuring out stuff: UC3842 + 100 MOhm resisitors + HV diodes + HV capacitors.. and you can have a regulated DC output
Dayton, you would be proud (read:ashamed) of how I grounded my tesla coil last night
no judgment here
We all do it
Grounding them? you would capacitance to the environment
Like metal mesh on the walls connected to the bottom
Ever tried a puddle of saltwater on your wood floor as a ground? Excellent ground.
Safe? Not one bit.
Sounds more like a Darwin award entry submission
Likely not too unsafe.. high frequency eletricity is way less harmful, but it can burn you
Fact, hand-held radios work better if you ground them to your person
It was a controlled puddle. But, I needed a particular shot for a video i'm producing. Otherwise - i'm usually quite safe. Last night was interesting though.
I've been wanting to build a tesla coil for haloween for years and I never get my ass in gear in time
My uncle used to tell me stories of a tesla coil he built in his youth using automotive ignition hardware he and his friends pulled from junkyard. Simpler times.
Well, looks like I scared J.B. Langston away...
True Dayton, or add an actual counterpoise at the resonant frequency.
Dave, give it a go. You will NOT regret building a TC
Jay: my HV supply, not got around to finishing it
Start small, so that your risk is minimal.
Absolutely, there are plenty of designs out there to have a crack at.
I have an eastern voltage research kit in my lap right now
Erlend. Is this what love feels like? That supply is just...mmm yes
that supply looks like two monitor flyback transformers?
Jay: positive output flyback + negative output flyback.. should be good for 60 kV.. I am just unsure about the circuit and various design faults
Dave: yes, but not from monitors
They are made for the task
beautiful. I'm currently building a 6 flyback powersource.
I have a metric shit ton of GM LSx ignition coils sitting around. They have built in ignitor modules and can make about a 2.5-3" arc while scrambling anything running on RF in the near vicintiy
Much less exotic than yours, and i'll be submerging it in oil
Note: all TV flybacks have positive outputs, you will likely never see one giving negative output
Dave, 3" arc?!
Still, that's somthing.
if you charge them with ~5ms dwell they will do that
feeding them a 5ms on - 5ms off square wave the "spark" looks like more of an arc because of the frequency
I have 3 ingnition coils sitting around, but as I mentioned earlier, I rarely use them. I'm sick of blowing through IC chips and transistors.
That reminds me, I've got this X-ray tube from the 60's sitting around, the darn thing needs like 150KV and a couple of amps. Need to figure out a power supply for the darn thing
The GM coils are made by delphi. They're stout.
Oh now you're talking Dayton. Where did you get that?!
^ one of those
Can we all take a moment to appreciate the brass knuckles in the picture?
Medical surplus from a bygone era
:) what brass knuckles?
Jay: Only get FET's that can avanalche, otherwise stuff fails and circuits blow up
I deny everything
Nice tube. How's the anode look? I had one removed from service that was all pitted and cracked.
Jay: And make sure they are well cooled, since they would likely get hot when you have no load on the output and all power is dumped in the FET
Erlend, thanks. I will look into this. I'm not too familiar with Avalanche circuits.
Admittedly, i'm a jack of all trades HV, but, actual circuitry i'm still learning
It's just a voltage limiting function, as in they will leak when the voltage gets too high, thus limiting the voltage
beware of vendor avalanche ratings
I got burned hard by this.
Anything particular in mind?
It's entirely possible to fudge datasheet ratings
Yes, with HV, always over-engineer!
Story time: (one moment)
many vendors will neglect to mention what thermal happens when avalanche occurs
high voltage + high current = crazy hot.. yep
so while their devices may technically do the avalanche behavior specified for a very short period of time, the device package can't even come close to dissipating the heat generated
The PowerSO8 and PowerDFN packages are particularly heinous for this.
For those who may not have seen my first message, about a tesla coil in high school: When I ran the tesla coil (360 watts....1.5 foot arcs) in the physics class, people cheered. Then, when I announced that any closed rings in the vicinity will conduct electricity...people didnt get it. Then, I looked to the ladies in the front of the class.......and pointed to my ears while insinuating *your* ears. They were all wearing large loop earrings. I've never seen human beings remove something off their bodies so fast.
@Jay Bowles what style / design was your 360W coil?
aside from earing remover ?
Jay: Or people that are afraid of electricity and doesn't see a problem with a frayed wire? strange
@Erlend Ervik : But I put some tape on it!
It's actually in almost all of my youtube videos, in the background. It's a standard full body tesla coil, multi Spark gap, with safety gap, multi-mini capacitor, and a cone (is that the word?) primary. Secondary is 24 inches tall and 4 inches wide. Topload is toroidal and three times the width of secondary. Secondary wound around ABS pipe (quite lossy)
what's lossy, the abs?
Jay: There are PEX pipes.. totally worthy for you to explore, it's close to the material used in CRT flyback output cables
The ABS has carbon in it, which makes the pipe more conductive than PVC
I thought it had a very low dielectric constant
PEX pipes. Never heard of those. I have a tesla coil build video coming up soon, maybe i'll incorporate
Hey so do I! (Making a TC video myself)
dumb question ... could you wind your coil around a form, apply epoxy or some kind of glue to the windings and then remove the central core you wound around? You'd only have an air core at that point
No clue about using it for secondary, but it's aparently close to the material used to isolate high voltage underground lines
PEX == cross-linked polyethylene, BTW
Interesting, I'd wondered in the past about that big coil that's behind your shoulder when you're talking into camera.
Its is less about dielectric constant, and more about being an air-cored transformer. Tesla Coils resonate at super high frequencies, and anything ferromagnetic or conductive inside the secondary coil reduces efficiency (for the most part)
Dave, without a form, there would be no rigidity
Dave, great idea. I bet you could. As long as you could guarantee the windings are stiff, and do not bend
That's were the glue comes in, no?
The form is definitely preferred thouhg, like Dayton mentions
Maybe in a vacuum chamber? low enough pressure allows close spacing for HV
True. Could use a lot of epoxy. I'm not too read up on how epoxy effects the output
I'm here for motivation and ideas from the experts.
I am impressed about how tiny gap they use inside CRT's
feel free to ignore me :)
Dave, YOU CAN DO IT! :)
General material info, a lot of black plastic and rubber compounds have carbon black.
Actually, lower pressure ensurages coronal discharge between all the turns. You'd want higher pressure air surrounding just the secondary itself. Topload would need to be outside it. Seems a bit too much work for me.
I need to wind coils for it
Jay: Well, yes.. but even lower pressure and there is no gas left for corona
ooh. solid state
True. I guess you'd need super low pressure.
I figured I'd let someone else do a lot of the thinking for me to start.
I am good with power electronics, just not high voltage stuff firsthand
Haha. Glad you're here Dave.
@Dave Blundell best way to begin. I started with Designs by Steve Ward with my DRSSTC's
I live at automotive "12V"
@Dave Blundell Why must you tempt me to buy more things I don't need? Very unfair, sir.
Ive met Steve Ward.
Dave, building one out of Soviet era surplus and having it explode into a cloud of Cadmium is just part of the fun!
Oh wow! Nice!
Steve Ward and Arc attack really started the solid state coil revolution
@Jay Bowles Totally! Ah, halcyon days!
What's the diff with solid state?
diff from what?
Solid state typically modulate square waves, which is fine, but not the way god intended
We use MOSFET's to switch voltage through the Primary, instead of spark gaps.
@Tom Nardi Yeah, the first coil I ever built (before the big one in my videos) was 1) ugly 2) LETHAL 3) almost killed me. So...I decided to actually research proper tesla coil building, and that lead me to the coil I used in High school. After 15 years, still works flawlessly. Over design anything, and it will never fail.
got it, thanks
I have a picture from when I was 16...I was leaning in to take a picture of the sparks, up close...one arc jumped to my hand, and the electricity exited...of all places...my groin. I was leaning against a grounded metal table. Anyways....my hand contracted as I flew back...and I still have a blurry photo somewhere of the exact moment I was sent flying lol
Let's raise funding for Wardenclyffe tower 2 - electric boogaloo
Again: dont learn like Jay did.
I have a healthy respect for high voltage. I got hit by the secondary side of an automotive ignition coil being driven by a fairly meaty capacitive discharge box. I figure it was around 36,000 volts (900V primary / 400:1 turn ratio) and that was plenty for me.
Dayton, I had a video call with the guy planning wardenclyff 2.0! He's really cool.
Jay, everybody learns that way