Electrical Why isn’t this Tesla coil working?

berkeman

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I am going to supply 120 vac from an electrical outlet
Can you say a few words about how you will make this connection to 120VAC Mains power safely? Where will you place the switch, will it be single pole or double pole? What fuse rating will you use and why? How will you handle the Line lead differently from the Neutral lead? Will your use of the AC Mains be singly-insulated or doubly-insulated? How does that affect whether you use a 2-prong or 3-prong power cord? How can the use of an AC Mains Isolation Transformer be useful in some test setups?

If you don't know the answers to those questions by heart, you should not be tapping into the AC Mains directly as a power source.
 
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What do others say; is this a safe DIY project for the OP?
As I see the OP is not really good with clarifying matters and giving answers. With that we does not even know how he want to utilize the line voltage. Directly powering the primary coil? Putting the 120V AC to the transistor? Adding some kind of power supply what he just forgot to mention? The possible consequences are quite different and I don't think we have to take the risk to guide an unwilling pupil here...

The key point is that with the involvement of the line voltage no part of this circuit can be considered safe any more. Adding in any details about why and how at this point makes no difference and feels like wasted effort. It does not feel like the OP could be trusted either.
 
I understand your concerns and take them seriously, especially since others will be around this apparatus. I will not connect directly into the AC mains but I was planning on using the 120 volts that is standard in most outlets using a proper transformer that I have acquired. The connected wire will be double insulated and will have a three prong connection in the outlet. And I will continue to do the calculations and ensure that the circuitry is plenty strong enough to handle such power.
 

anorlunda

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I understand your concerns and take them seriously, especially since others will be around this apparatus. I will not connect directly into the AC mains but I was planning on using the 120 volts that is standard in most outlets using a proper transformer that I have acquired. The connected wire will be double insulated and will have a three prong connection in the outlet. And I will continue to do the calculations and ensure that the circuitry is plenty strong enough to handle such power.
Forgive our directness, but what you've shown us so far do not impress.

Hand waving, "I'll put in a transformer," is not persuasive unless you have to skills to ensure that there is no chance for a short circuit between primary and secondary. The picture of your original layout looks as unsafe as it could be.

You have not commented on this;
The only Tesla coil I've seen IRL (at the Griffith Observatory in LA) was safely enclosed in a Faraday cage.
You are getting ideas from Youtube videos from amateurs with unknown credentials. Now you are departing from those instructions.

Even when there is only one person in a project, a "culture of safety" is still needed.

PF members: If we were to write a "safety code" for such a project, what would it say?
 
I guess all I can comment is, the pictures you saw before were incredibly messy and certainly unsafe. Once the series vs parallel problem was worked out I fixed everything before ever applying power again. The Tesla coil at the Griffith Observatory has millions of volts for output and is at least quadruple the size of mine. The YouTube videos were not where I was getting all of my information just references to what others have done. As to the transformer concern that was just a statement. I have a proper power source now, not some batteries on a table. I have everything properly insulated now and there is a metal rod that is grounded right near the plasmatic discharge to catch any sparks that could cause a short circuit between the coils. Going any further safety is a MUST and I don’t take lightly to the actual possibility of anyone getting hurt by carelessness. The whole reason this post is still open is because people need to see how to safely do any kind of project with high voltage and for people to comment on higher power rated parts so I can continue this project as safely as possible.
 

berkeman

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I will not connect directly into the AC mains but I was planning on using the 120 volts that is standard in most outlets using a proper transformer that I have acquired.
It's good that you plan to use a transformer to isolate the AC Mains connection from your application circuit. But you still did not address the Line/Neutral question, the Switch question, or the Fuse question that I asked. That's worrisome for me.
The connected wire will be double insulated and will have a three prong connection in the outlet.
The wire insulation is only a small part of the safety aspects of using such a power source. If your transformer is doubly-insulated and you use other proper construction techniques, then the 3-prong power cord is not needed. If you use a singly-insulated power supply design, then you generally will need to use a 3-prong power cord and attach the Earth Ground wire to your project in some very particular ways.

I would recommend that you just use a pre-made 120V/24VAC transformer that already has appropriate UL safety approvals (or other agency approvals, depending on where you live). That is by far the best approach for your early electronics projects, until you can find a local Mentor to help you with safety aspects of higher-voltage AC Mains based projects. You can use such a packaged transformer for many of your DIY projects going forward. They are available in many power levels at reasonable prices.

https://cdn3.volusion.com/czamo.vpczb/v/vspfiles/photos/115-24VAC1000-4.jpg?1492079340

upload_2019-2-20_8-55-14.png
 

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I believe I have the power source problem is mostly dealt with but there is still the concern on what MOSFET to use, it must be high power and extremely fast switching, and how much I’m expecting to need the resistor to stand up to without burning. I will definitely consult a local professional for all upcoming projects that involve electrics.
 

anorlunda

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We can't expect DIY projects to meet the same standards as professional laboratories or work shops. But neither should we offer advice to DIY projects that may cause injury or worse.

The primary safeguard is to see that the DIY project has oversight from an experienced mentor. Sometimes, local hobby clubs can provide that.

The first thing that the mentor can do is to compare the skills of the hobbyist with the intrinsic dangers of the project. In a case such as this one, I would advise the OP to abandon the Tesla Coil project, and to choose a less risky one.

The second thing for the mentor is to look for the many ways that things can go wrong and to suggest to the hobbyist ways to avoid them or to mitigate them.

Online public discussions with strangers is no substitute for a face-to-face relationship with a mentor.

So, I'm going to enforce PF's rule forbidding public discussion of dangerous topics. Thread closed.
 

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