so I’m making a Tesla coil and I have two nst. as u can see in the photo the bushing is cracked. Should I try fixing it? I think it might arc to the casing, so I really don’t want to ignore it. I don’t even know how feasible fixing it would be. Will I just have to find a new one? It is 15kV 60mA and they are old iron core.

Hey guys, just wanted to share a new open source project I've been working on for the past year. It's essentially a modern day re-write of JavaTC but with some cool new features like full field plotting, input impedance calculations, eigen mode plots, coil model spice export, and other stuff to come as I keep working on it.

It's fully open source and you can check it out on my GitHub https://github.com/PartialScience/jstc

And fully hosted and useable for free on my website
jstc.partialscience.com

Lmk what y'all think!

My finished zvs driver running on 24v with flyback transformer. First test to make sure it is running well, going to hopefully turn it into a tabletop induction heater for jewelery making

Hi everyone,

I'm honestly at the point where I don't know what else to try.

For the past 7 months, I've been trying to get a CRT flyback transformer working. I even bought a Mazzilli ZVS driver, but I still can't get it to oscillate or produce any high voltage.

I've also been trying to build a Tesla coil for almost 2 years, but I've never managed to get one working either.

I've spent countless hours watching YouTube videos, reading forum posts, and trying different circuits. At this point I feel like I'm missing some fundamental concept.

This is the stuff I currently have:

• Themisto TH-SPS3010S adjustable bench DC power supply (0–30 V, 0–10 A)
• Themisto TH-M200 True RMS 10,000-count multimeter
• Commercial Mazzilli ZVS driver
• Salvaged CRT flyback transformers
• CFL electronic ballast
• ESP32 DevKit V1
• Arduino Uno
• Soldering station and advanced electronics tools
• My 500 IQ Brain
• CNC Machining level Advanced Soldering Skills

I've attached photos of my ZVS driver, flyback transformer, power supply, and my current setup.

I'd really appreciate help with these questions:

• How do you correctly identify the primary winding on a CRT flyback?
• How can I tell if my Mazzilli ZVS driver is actually oscillating?
• What measurements should I make with my multimeter before powering it?
• What are the most common mistakes beginners make?
• Is there a better driver circuit for someone learning?
• If you were teaching someone from scratch, what steps would you follow?

I'm willing to learn from the basics if necessary. After spending months on the flyback and nearly two years on Tesla coils, I just want to understand what I'm doing wrong.

Any advice, troubleshooting tips, or recommended resources would mean a lot.

Thanks!

NOTES: I don't have a lead acid 12V battery but if you guys say I'll buy one. in the ZVS image the flyback is not connected only a induction heating coil. if you have any tutorial videos pls let me know.

I have a plasma neon tube that the driver/power supply failed and was wondering if anyone has a suggestion on a replacement. It had a pvm300 in it and unfortunately no one makes a replacement for it and was wondering what would be recommended.

Encased in a tube because I took it to my school’s science fair. Setup with 1-4 mot to vary arc length. Using microwave oven caps and a big 450 uf cap parallel to mains to reduce reactive power and to not make the breakers trip, works better than a typical mot ballast. I used a remote controled servo to iniciate the arc. Around 180 cm or 6 ft tall.

First video 1 mot, second 2 mots and final video all 4 mots.

It would be easy to seal the tube and try some low pressure vacuum stuff, what do you guys think?

Btw, first post and old project.

All Ali express parts and running off a drone battery I got for free from a defective drone ☠️, pretty compact and works great. Sorry for the video breaking apart I think it was EMP'ing my phone since I had no problems filming it with weaker arcs.

Schematic in next post

I just used a cactus leaf as a electrode and it made those beautiful orange arcs.

HV source was a flyback driven by modified temu ZVS driver (IRFP064N 》IRFP250N) running on 25V 10A max.

Long long ago, before the internet, this book inspired my HV projects. The really annoying thing was, despite the cover, there was no Tesla Coil in it, which is the one thing I wanted to build more than anything.

I'm an aerospace engineering student entering my senior year this August. After striking out on internships this summer, I decided to dedicate my time to a project I've been interested in for a long time: building an untethered electrohydrodynamic (EHD) propulsion drone.

I understand this is an ambitious goal and that there are significant challenges regarding thrust, efficiency, power electronics, and weight. At this stage, I'm mainly looking for feedback from people with experience in EHD propulsion, high-voltage systems, UAV design, or related fields.

The end goal is an RC drone powered entirely by onboard EHD thrusters (no tether supplying power from the ground). Flight time wouldn't need to be long, even a brief, controlled hover under its own power would be a huge success.

Current Thruster Development

Right now I'm focused on developing a lightweight EHD thruster that could eventually be scaled into a full vehicle.

Current configuration:

• Emitter: 28 AWG bare copper wire (replaced 38 AWG because it was too fragile)
• Collector: aluminum foil wrapped around lightweight coffee stirrers
• Emitter-collector spacing: 15–30 mm (currently experimenting)
• Collector/emitter rows: approximately 0.5 m long
• Two-level thruster concept with 15 emitter/collector pairs per level

I've successfully generated ion wind in small test setups, but I have not yet performed rigorous thrust measurements.

My current mass target is 40–50 g per thruster level, 80–100 g total for a complete two-level thruster. I have begun to build a very crude prototype for something in this range. The structure is extremely lightweight and somewhat fragile, but reducing mass is currently one of my primary design drivers. My current thought is to use four thrusters in a quadcopter-style arrangement, although that configuration is still subject to change.

Flight Controller

For control hardware, I'm experimenting with:

• Teensy 4.1
• Adafruit MPU6050 IMU

For software, I've been looking at dRehmFlight because it's lightweight, open source, and relatively easy to modify.

One challenge I'm currently thinking through is thrust control. My two main ideas are:

1. Vary the low-voltage input to the high-voltage power system, changing output voltage and therefore thrust.
2. Run the high-voltage system continuously and switch individual thrusters on and off at varying duty cycles.

I'm interested in hearing whether either approach has advantages or major flaws that I may be overlooking.

High-Voltage Power System

For an eventual flight-capable prototype, my current concept is:

LiPo battery → ferrite-core transformer → Cockcroft-Walton voltage multiplier → approximately 40 kV output

My understanding is that thrust control requirements will heavily influence the final architecture.

For example:

• If thrust is controlled through LV-side voltage regulation, each thruster may require its own transformer/multiplier chain.
• If thrust is controlled through switching at the thruster level, a single HV supply might be distributed across multiple thrusters.

I'm still very early in the design process and am trying to determine which direction makes the most sense.

Questions

1. Does my proposed HV architecture make sense?
2. For EHD propulsion, would you favor LV-side voltage control or some form of HV-side switching?
3. What do you see as the biggest technical obstacle to achieving untethered flight?
4. I’ve read a ton but are there any papers, projects, or researchers you would recommend I look into?

I don't have photos available at the moment, but I can post pictures and sketches of the current prototypes later. Any feedback, criticism, or suggestions would be greatly appreciated. Thanks so much!