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Messages - Michelle_

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Beginners / Re: Help with LabCoatz's Staccato QCW DRSSTC Tesla Coil

« on: May 12, 2024, 04:24:44 PM »

Quote from: alan sailer on May 12, 2024, 04:10:54 PM

Michelle wrote,

Any suggestions on an alternative QCW driver that could be a backup for this that can use the same secondary?

At the risk of being a tesla pedant, LabCoats "QCW_ coil is not a QCW coil. It's a ramped, or RDRSSTC. A true QCW
coil uses buck converter to generate a very long ramp. A RDRSSTC uses the leading edge of a sine wave to generate
a much shorter ramp.

A great description of the build of an RSSTC is by loneoceans,

https://www.loneoceans.com/labs/sstc3/

LabCoats borrowed this design for his own project. I am not sure if he even gave loneoceans credit. I also think he uses
the term QCW for his coil to make it sound like he has created a much more difficult type of device.

To answer your question, the ramp generation circuit in LabCoats in his design appears to work fine. It's identical to
loneoceans design.

Cheers.

Not pedantic at all just facts! Thanks for explaining the difference. I think it’s crucial to rightfully call things what they are when it comes to things like this.

Beginners / Re: Help with LabCoatz's Staccato QCW DRSSTC Tesla Coil

« on: May 12, 2024, 04:04:11 PM »

Quote from: hal7rr on May 12, 2024, 03:56:57 PM

Quote from: Michelle_ on May 12, 2024, 03:46:45 PM

As for solid state I think most of them can depending on the voltage rating of individual components, but you should probably consider getting a variac either way so you can ramp up voltage for testing. 240VAC is pretty dangerous to play with for a first tesla coil and you also need to be aware of whether this is single phase or not, etc... At least in America once you're talking about line voltages of 208, 220, 240, they don't always work the same way.

I would recommend looking here:

https://kaizerpowerelectronics.dk/tesla-coils/kaizer-sstc-ii/

Kaizer's designs are fundamentally sound and similar to the popular (for a reason) Steve Ward designs. The reason these designs are popular is because they don't have any funny business and contain the basics that are needed to have a reliable and functional tesla coil (interrupters, gate drivers, etc...). Things like QCW are similar in many respects but are more complicated. Even the basic ones like the steve ward SST5 will take quite a bit of understanding to build, but if you can build it and understand it you'll be way better off than blindly putting parts into a PCB that's not very serviceable or easy to trace, modify, repair, etc...

Noted. I'll have a look at the designs and I'll definitely invest in a variac! Quick question about the variac. Looking at the prices online, they range from about $50-$200+. Does it matter if I get a cheap one or should I invest in an expensive one?

It does matter, based on what I’ve read the cheap Variacs from China that you find in that price range can be potentially dangerous at worst and at best may not stand up to their rated current or long term use. Most people recommend looking for an older used unit from a good brand. Personally I’m a tool snob and am willing to spend $$$ to get things that will last and not fail at the worst possible time. It’s a habit that’s served me well as a technician and engineer and now I have a bunch of nice tools that still work and are worth something (can be a slight curse lol I can’t even lift up my sockets and ratchets section alone). So I’d google a bit then look on eBay or wherever you can buy used equipment and get something decent but I understand not everyone has an unlimited budget just be aware that with things like this they are not all created equal.

Beginners / Re: Help with LabCoatz's Staccato QCW DRSSTC Tesla Coil

« on: May 12, 2024, 03:46:45 PM »

Quote from: hal7rr on May 12, 2024, 02:59:16 PM

Hmmm, it does seem that I'm in way over my head. I picked LabCoatz's cause he had a 240 VAC version which a lot of the designs I saw did not + the videos I saw and the comments all said it was relatively straightforward to build (tho they probably are more knowledgable than me lol). Can anyone recommend simple SSTC designs that can handle 240 VAC as I'm based in the Middle East.

It depends what your goals are. If you want the simplest tesla coil that can make decent sized sparks something like the ZVS flyback driven spark gap unit I made running off a PSU that converts to DC (That will accept 240 no problem) can get you pretty far and requires extremely little potential troubleshooting as long as it's been designed properly to begin with. You can also build a spark gap tesla coil with a neon sign transformer. There's a reason most people start off with these it's because you learn the fundamentals but there are no electronics to complicate them.

As for solid state I think most of them can depending on the voltage rating of individual components, but you should probably consider getting a variac either way so you can ramp up voltage for testing. 240VAC is pretty dangerous to play with for a first tesla coil and you also need to be aware of whether this is single phase or not, etc... At least in America once you're talking about line voltages of 208, 220, 240, they don't always work the same way.

I would recommend looking here:

https://kaizerpowerelectronics.dk/tesla-coils/kaizer-sstc-ii/

Kaizer's designs are fundamentally sound and similar to the popular (for a reason) Steve Ward designs. The reason these designs are popular is because they don't have any funny business and contain the basics that are needed to have a reliable and functional tesla coil (interrupters, gate drivers, etc...). Things like QCW are similar in many respects but are more complicated. Even the basic ones like the steve ward SST5 will take quite a bit of understanding to build, but if you can build it and understand it you'll be way better off than blindly putting parts into a PCB that's not very serviceable or easy to trace, modify, repair, etc...

Also it’s ok to try things and make mistakes, I’ve made plenty so far and still have a lot to lean. but try to lean from them and know when to listen to people that know more. You don’t always have to do what they say but at least try to understand why they are telling you what they are.

Solid State Tesla Coils (SSTC) / Re: Quick question about steve ward mini SST5 resonant frequency

« on: May 12, 2024, 02:51:27 PM »

Quote from: ZakW on May 12, 2024, 08:34:39 AM

I would add that since the coil is self tuning the exact frequency doesn't really matter. As long as the secondary fres isn't so high that it causes a lot of switching losses or out right exceeds some of the selected part specifications.

For the common schematics and parts used in them I have run them around 500kHz but again that depends if you're using IGBTs or MOSFETS as well as gate drive etc. The standard designs are pretty good up to around that fres and should work just fine.

When possible I would recommend using secondary feedback over antenna for these designs.

-Zak

Thank you that's helpful. My only beef with the SST5 is that the 4.5x10" secondary isn't very mini... so if I have a range of acceptable frequencies (I knew it was self tuning but not to what extent) I can look at making it a bit shorter.

Beginners / Re: Help with LabCoatz's Staccato QCW DRSSTC Tesla Coil

« on: May 12, 2024, 02:49:42 PM »

Quote from: ZakW on May 12, 2024, 08:30:29 AM

Quote
Any suggestions on an alternative QCW driver that could be a backup for this that can use the same secondary?

Check out my ramped sstc thread in my signature. Full schematic on page 4.

Labcoatz QCW coil has many issues and is not a good beginner coil. Good luck!

-Zak

Thank you, your results and quality of work speak for themselves, I am inclined to listen to you and Alan so I will keep an eye on this thread (if it is updated) and as for myself most likely change directions and build your version of the QCW coil. At this point I'm only out a few bucks for the PCBs but I can always give it a shot down the road when I understand what's going on better.

Beginners / Re: Help with LabCoatz's Staccato QCW DRSSTC Tesla Coil

« on: May 12, 2024, 02:35:17 AM »

Quote from: alan sailer on May 12, 2024, 02:07:32 AM

Good luck to all. I had built about seven tesla coils (including two QCW coils)and the LabCoats PC
board proved my undoing. After blowing up several sets of IGBJTs and learning nothing I threw
the whole project in the trash.

To be clear, I am not saying that there is a fatal flaw in the board. I just could not get it to work well
at all.

Cheers.

Any suggestions on an alternative QCW driver that could be a backup for this that can use the same secondary?

Beginners / Re: Help with LabCoatz's Staccato QCW DRSSTC Tesla Coil

« on: May 11, 2024, 09:55:59 PM »

I'm building the same design. Good luck, this is optimistic for a first build however it's well documented and already has a PCB so as long as not much goes wrong it should work out. It sounds like it's too late now but I would have recommended starting with a SGTC, then building a regular SSTC first to build your understanding because now you will be lost trying to troubleshoot a far more complicated system. Also building your own secondary instead of ordering one would have also been an incredibly valuable learning experience but I guess it depends on whether your goal is learning more or just building a tesla coil. Anyway I digress.

1.) The number of pins is irrelevant as long as you get the input and output voltage you need. The reason there are different amounts of pins is because some of them accept and output different voltages depending on how they are connected.

2.) I'm sure he means the whole bank because the individual capacitor voltage rating is meaningless since they can be connected in different ways and numbers in a MMC.

3.) You can go by various rules of thumb (google them) but one of the most important things is making sure your resonant frequency will be in your target range (the coil with the top load) - just use javaTC to estimate it if you don't have it on hand to test with a signal generator and oscilloscope. I would suggest making the toroid easy to remove and change out so you can try different sizes. Generally AFAIK smaller ones store less energy before the spark breaks out so a bigger one will have bigger sparks, up until the point it is too big and strains the drive electronics or can't break out anymore.

Solid State Tesla Coils (SSTC) / Re: Weird AC/DC mini SSTC build review

« on: May 11, 2024, 05:27:22 AM »

So I realized I can't reuse this secondary for my next project so I spent some more time tinkering with it and now I feel a lot more optimistic about the design. Running on AC anyway.

Now it draws only 2.5A and hardly gets warm with 15+ minutes of use which is good, even pulling arcs won't trip my 3A circuit breakers.

Arcs are quite small as stated about 6cm but again it lights things up pretty well. Since it draws less than 3A I can use a much cheaper and lighter transformer than the 4A unit I was looking at before, so I will probably put it in an enclosure and either leave it on my desk at work or give it away, especially since it can just run off of a wall outlet. I will keep the circuit protection and probably use a small 5V PSU for fans.

The unit is pretty quiet besides emitting a quite pleasing (to me) deep humming, and the arcs seem relatively safe to touch. After messing around with it for a pretty long time it seems solid now and even though it's weak it's fun to play around with.

Thought I would mention the secondary is only 4" winding and 2" in diameter so this thing actually is super small. The steve ward "mini" sstc I realized has a 10" tall secondary lol and his "micro" sstc is 6" (?) and has less output than this one so I feel better about it to be honest. That said my output is less than in the video but I'm not totally sure why, on the other hand my current draw is a lot lower which seems good for what I'm using it for, not sure if it's because of my isolation transformer limiting the current somehow or if I made a mistake in the design.

Solid State Tesla Coils (SSTC) / Re: Quick question about steve ward mini SST5 resonant frequency

« on: May 10, 2024, 09:24:21 PM »

Quote from: alan sailer on May 10, 2024, 08:43:11 PM

The schematic Steve supplies shows the dimensions of the secondary coil. Plugging these numbers into JAVATC
gives a secondary frequency (minus top-load) of 260kHz. Adding the top-load gives ~220kHz.

Cheers.

Oops I guess I could have just done that. Thanks Alan, I want to build this so I'll just aim for that frequency. I was going to reuse a secondary I have but the frequency I'm sure is way too high.

Solid State Tesla Coils (SSTC) / Quick question about steve ward mini SST5 resonant frequency

« on: May 10, 2024, 08:33:47 PM »

Does anyone know that the ideal or suggested secondary resonant frequency is for this, or what range will work? I can't seem to find that tidbit.

https://www.stevehv.4hv.org/SSTC5.htm

Solid State Tesla Coils (SSTC) / Weird AC/DC mini SSTC build review

« on: May 10, 2024, 05:34:15 AM »

I'm just posting this in case anyone else searches for information on this.

"Mini SSTC IV"

https://www.vn-experimenty.eu/teslov-transformator/sstc/mini-sstc.html

/>
(this is not my video, it's where I found the idea)

I thought the circuit looked interesting and I had basically everything to build it, so I decided to give it a try because I was curious what such a simple circuit can do.

My feedback is that in DC mode it is really stressing the transistor and even with fans things get pretty hot. The two diodes in particular got hot, and I put a 24V mini blower fan pointed directly at them. In CW mode the transistor could get hot enough to die after 5-10 minutes or so even with a heat sink and fan, running at full output. Full output required a stronger PSU than my lab PSU so I used a 20A 24VDC din rail mounted PSU that could adjust to 28V. The difference between that and the lab PSU was dramatic, even though I ran it through a 6A breaker (which was a good idea because it popped a couple times). The secondary got hotter than I would like as well in CW mode and I had concerns about its long term survival.

Ultimately I killed all 5 of the transistors I bought during testing so I wouldn't really recommend this as a long term solution.

I tried a few different top loads, primary windings and positions, and they all had an effect on the current draw and to some extent the performance.

I did run it off AC using a variac and isolation transformer. It did appear to be able to run continuously without any overheating in this mode but the performance was not particularly inspiring. Arcs were maybe 6cm at most. I would have maybe kept it in this configuration as it was stable and only drew 3A, to give away to someone, however it would require a 48V transformer, which is $47+ shipping from digikey and 6lbs (3kg) for a 4A unit which seems dumb to do.

The most impressive thing this setup can do however is light up tubes. It can light up tubes and CFL bulbs from 3+ feet away in CW mode.

Overall it would be a good build for a first tesla coil because it's easy but significantly more powerful and robust than a regular slayer exciter.

That said I built a fairly nice secondary so I'm going to repurpose it with a nicer driver, and I think I'm going to build the steve ward mini SSTC driver for it, which is more complicated but will be a good learning experience and presumably work more reliably long term.

I've attached a picture of the schematic, bare driver board (before I added a bigger heat sink, mounted it to a platform, and added fans), and a couple shots of it running in CW mode. I didn't take any good pictures of it with the toroids or running in AC mode but I'm going to reuse the secondary and toroids so I will post it after I build the steve ward driver.

EDIT: Actually I might have to wind a new coil for the steve ward SSTC anyway because of the resonant frequency, so maybe I will see about a smaller transformer and trying to cool this properly and give it away after all. Maybe there's something I can do to boost the performance on AC.

Beginners / Re: Question about using mains power and variacs to power this circuit

« on: May 10, 2024, 05:08:38 AM »

Quote from: klugesmith on May 09, 2024, 07:10:19 PM

On the topic of isolation, since oscilloscopes came up...

Let's say someone had a battery powered oscilloscope with an ethernet port for communicating with a PC.
The scope ground could be connected to hot side of AC line, and copper-wired Ethernet would still work, completely within spec.
Thanks to its mandatory isolation transformers, usually built into the board mounted "RJ45" connectors.
It's an exercise I have never personally done or seen done.
[edit]
https://www.we-online.com/en/components/products/WE-LAN-RJ45
I had forgotten about power over Ethernet, but I bet that would also work and be within spec.

That's interesting. Ethernet standards are pretty amazing actually. What a great invention.

Anyway I ran the circuit on AC. I guess I'll post a thread on it in case anyone in the future tries to build one. I'm ultimately going to repurpose the secondary though.

Beginners / Re: Question about using mains power and variacs to power this circuit

« on: May 09, 2024, 03:42:49 PM »

Also just some feedback, I don't know what you guys do for work, but if someone asks you a question about the safety of a specific task they're doing, please give them specific actionable advice because a generic answer is unhelpful as far as keeping that person safe. If they are asking you, then they already know there's something to be aware of and they need specific and actionable information. I would usually say "there's nothing specific to watch out for besides following typical safety procedures" just so the person isn't wondering if there's something they could be missing, and it reassures them that they understand what they're doing which helps their confidence.

- Someone that manages and trains engineers and technicians

Beginners / Re: Question about using mains power and variacs to power this circuit

« on: May 09, 2024, 03:06:19 PM »

Quote from: Mads Barnkob on May 09, 2024, 01:05:26 PM

A variac / auto transformer is not isolated from mains and you can therefore NOT ground the neutral. Grounding neutral or negative on a isolation transformer or DC power supply, is to get all voltages to refer to a common earth. So you are sure to have a path to ground for fault currents. This is called PELV or SELV.

Isolation transformer after variac, so that peak loads are at a higher voltage, low voltage high current tends to damage the rollers in a variac.

All work with electricity is dangerous.

Thanks Mads I see what's going on now I think. I didn't know there was a name for that practice but that makes it easier to look into. Now that I think about it I've seen neutral to ground in control cabinets sometimes after trasnsformers and wasn't sure what to make of it, but now I realize why they did it and why it works.

Makes sense about putting the transformer after the variac to not damage it, that's why I asked before I went and just did it.

Thanks

Beginners / Re: Question about using mains power and variacs to power this circuit

« on: May 09, 2024, 02:16:30 AM »

I was intrigued by this circuit when I stumbled across it so I built it since I had almost all the parts. It works great with DC so I want to try AC now...

Might post a thread on it later but for now it's just in parts and the top load/base isn't finished but it works well especially for lighting up tubes.

(also I switched to a WAY bigger heat sink and a fan)

Beginners / Re: Question about using mains power and variacs to power this circuit

« on: May 09, 2024, 02:00:28 AM »

Quote from: unrealcrafter2 on May 09, 2024, 12:48:57 AM

I don't think you Need to use an isolation transformer. It just helps with safety. Unless you are using an oscilloscope you can probably get away without an isolation traffo. Id personally just use a lab bench power supply instead.

Mainly if you run it un isolated make sure you don't hook the Hot to the GND

If you already have an isolation transformer it would probably be better before the variac so you aren't underpowering it

Also general note only touch a HV circuit with one hand at a time

I have a lab bench power supply, it outputs DC, I'm talking about powering this with 48VAC by lowering mains (110) voltage with a variac. Hooking the variac up with neutral to ground trips the GFCI, and the video where the designer of the circuit sort of explains what's going on here mentions using an isolating transformer, which is why I'm trying to make sure I understand what's going on instead of trying a circuit without GFCI (if I even have one which I may not).

I already know about touching things with one hand I'm asking for information specifically about running neutral from an isolated power supply to mains ground and whether or not to hook the variac up before (where it is grounded to mains) or after the isolation transformer (which has a 2 prong outlets with no ground).

I've never seen a circuit like this before and don't typically mess with mains power so I'm trying to learn more.

Beginners / Question about using mains power and variacs to power this circuit

« on: May 08, 2024, 08:10:41 PM »

So for DC this makes sense to me, but say one wants to power this with a variac from mains... Am I right in understanding that:

1.) You need an isolation transformer

2.) You would hook "line" [after the isolation transformer] (either of the wires) to where DC+ would go

3.) You would hook "neutral" [after the isolation transformer] (the other wire) Up to the grounded point of the circuit, which would also be hooked up to mains GND

4.) Question: Would you want to put the isolation transformer before or after the variac?

5.) Is there anything dangerous to be aware of if attempting this?

Dual Resonant Solid State Tesla coils (DRSSTC) / Re: Plasma Torid - Class E Self Resonant Dual/Stereo - Plasma Torid Build

« on: May 08, 2024, 07:33:43 PM »

Check out what I found, there are mini plasma toroid generators and gas globes on aliexpress now:

https://www.aliexpress.us/item/3256806678903018.html?spm=a2g0o.store_pc_home.0.0.5f617d84Qz3GxW&gps-id=pcStoreNewArrivals&scm=1007.23409.271287.0&scm_id=1007.23409.271287.0&scm-url=1007.23409.271287.0&pvid=6decdcb1-6444-48cb-974b-92feb59ace40&_t=gps-id%3ApcStoreNewArrivals%2Cscm-url%3A1007.23409.271287.0%2Cpvid%3A6decdcb1-6444-48cb-974b-92feb59ace40%2Ctpp_buckets%3A668%232846%238108%231977&pdp_npi=4%40dis%21USD%2165.39%2165.39%21%21%21470.06%21470.06%21%402103297417151892807003769e32cb%2112000038817558759%21rec%21US%211653574204%21&gatewayAdapt=glo2usa

https://www.aliexpress.us/item/3256806669523156.html?spm=a2g0o.detail.pcDetailTopMoreOtherSeller.4.ec63H3YtH3YtEv&gps-id=pcDetailTopMoreOtherSeller&scm=1007.40050.354490.0&scm_id=1007.40050.354490.0&scm-url=1007.40050.354490.0&pvid=9709064f-d643-43e5-8869-5c45b5219357&_t=gps-id:pcDetailTopMoreOtherSeller,scm-url:1007.40050.354490.0,pvid:9709064f-d643-43e5-8869-5c45b5219357,tpp_buckets:668%232846%238108%231977&pdp_npi=4%40dis%21USD%2185.13%2185.13%21%21%21612.00%21612.00%21%402101e7f617151892895093313ecccc%2112000038526756379%21rec%21US%211653574204%21&utparam-url=scene%3ApcDetailTopMoreOtherSeller%7Cquery_from%3A

Spark Gap Tesla Coils (SGTC) / Re: Small-ish 3D printed SGTC via cheap ZVS flyback build, humbly asking a couple ?s

« on: May 07, 2024, 06:46:16 PM »

Quote from: NyaaX_X on May 07, 2024, 11:00:00 AM

That works fine... I don't know if I make my topload bigger. Can it store more energy and generate a longer and concentrated arc? My arcs only 15cm+ I think...

My plasma globe had been broken by my sstc few months ago. I was guessing the pulse arcs hit it in one point and the transient energy heating and breaking through the glass randomly, whatever. I still have a tube of Neon and another tube of Helium.

It might be worth trying a bigger top load, yours is running 24v right? I'd check the voltage across the spark gap and see what voltage you're actually getting. I have 12000v across my spark gap, and my system is also fairly optimized I think.

I might try a bigger topload but I'm not too worried about it, althoguh I'm curious if I can actually hit the 18"/45cm sparks the deepfried neon formula claims. I'll need to check in javaTC because I only have around 1.5 more primary turn of adjustment left and increasing the capacitance of my MMC is out of the question because I would need to start running parallel strings.

edit: checked javatc if I change my top load OD from 9" to 11" it should require exactly 1 extra turn to tap which I have, so I'll try it then seeif it makes a difference. I made the topload modular so it just lifts off and mates onto a post which also doubles as the electrical connection. I can print it at 5% infill with gyroid infill pattern at least with PETG so it's not too ridiculous even though it's a huge part.

Solid State Tesla Coils (SSTC) / Re: 3D printed mini-slayer: world's weakest tesla coil

« on: May 06, 2024, 04:43:19 PM »

Quote from: Mads Barnkob on May 06, 2024, 04:26:44 PM

The secondary wire looks pretty thick, 0.2 mm? You might need to use hair thin wire to get the frequency down, to lower losses and get better output.

Also as stated, a topload would help on bringing down the resonant frequency and give some stability to the output.

Thanks mads yes it’s .25 it’s quite thick, I made this before I knew anything but now that I think about it I should wind a new secondary now that I’ve learned more. Might as well since I have a case for it. All it has is a BD243 transistor and the 9v battery so it’s weak but now I’m curious how powerful it can be.

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Show Posts

Messages - Michelle_

Beginners / Re: Help with LabCoatz's Staccato QCW DRSSTC Tesla Coil

Beginners / Re: Help with LabCoatz's Staccato QCW DRSSTC Tesla Coil

Beginners / Re: Help with LabCoatz's Staccato QCW DRSSTC Tesla Coil

Solid State Tesla Coils (SSTC) / Re: Quick question about steve ward mini SST5 resonant frequency

Beginners / Re: Help with LabCoatz's Staccato QCW DRSSTC Tesla Coil

Beginners / Re: Help with LabCoatz's Staccato QCW DRSSTC Tesla Coil

Beginners / Re: Help with LabCoatz's Staccato QCW DRSSTC Tesla Coil

Solid State Tesla Coils (SSTC) / Re: Weird AC/DC mini SSTC build review

Solid State Tesla Coils (SSTC) / Re: Quick question about steve ward mini SST5 resonant frequency

Solid State Tesla Coils (SSTC) / Quick question about steve ward mini SST5 resonant frequency

Solid State Tesla Coils (SSTC) / Weird AC/DC mini SSTC build review

Beginners / Re: Question about using mains power and variacs to power this circuit

Beginners / Re: Question about using mains power and variacs to power this circuit

Beginners / Re: Question about using mains power and variacs to power this circuit

Beginners / Re: Question about using mains power and variacs to power this circuit

Beginners / Re: Question about using mains power and variacs to power this circuit

Beginners / Question about using mains power and variacs to power this circuit

Dual Resonant Solid State Tesla coils (DRSSTC) / Re: Plasma Torid - Class E Self Resonant Dual/Stereo - Plasma Torid Build

Spark Gap Tesla Coils (SGTC) / Re: Small-ish 3D printed SGTC via cheap ZVS flyback build, humbly asking a couple ?s

Solid State Tesla Coils (SSTC) / Re: 3D printed mini-slayer: world's weakest tesla coil

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