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Flyback driver help needed

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djrobotfreak

Apr 14, 2010
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Hello everyone, I am having problems getting even the simplest flyback circuit to work. I have made a youtube vid so maybe someone can identify my mistakes. Thanks to anyone that can help!


Things that I might be doing wrong:
I wired the primary and feedback on the core right next to one another. Is that right?
Maybe I didnt turn the flyback on? Do I need to give it any power (12 V) besides my turns of wire on the core?
 

55pilot

Feb 23, 2010
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No idea what you are trying to do and why. Step back and start with the big picture.

---55p
 
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(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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Do you have some form of circuit diagram? This looks remarkably like you're using DC with a transformer and expecting something to happen.
 

djrobotfreak

Apr 14, 2010
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Look in the comments and watch that vid to see what I'm doing. I am using a 2n3055 to give an ac like circuit
 

55pilot

Feb 23, 2010
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Look in the comments and watch that vid to see what I'm doing. I am using a 2n3055 to give an ac like circuit
Still does not make any sense. If you want help HERE, please start by explaining EXACTLY what you are trying to achieve, HOW you are trying to achieve it and what you have managed to so far. Start by posting a schematic.

Do not make assumptions about people being able to read your mind.

Do not make assumptions that people know the standard lingo of your particular hobby or field.

For starters, what are you calling a "Flyback driver?" I can think of at least 3 different things that would qualify as such.

---55p
 

djrobotfreak

Apr 14, 2010
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I am sorry for any confusion

I'll start from the begging. When I started this project I wanted to make a plasma speaker. I tried using a couple of different schematics including these two:
http://www.instructables.com/id/Build-A-Plasma-Speaker/step2/Schematics/
and
http://www.instructables.com/files/orig/FVE/I3SC/FR123O01/FVEI3SCFR123O01.png

I attempted to do this many times and could not make any thing come out. To see what a plasma speaker is look here:
That large arc is actually creating the sound you can hear (incidentally only out of the left speaker)

When I could not even create the arc I moved to a flyback driver which is a simple version of a plasma speaker in that it does not make the music, just big sparks. The most important item in both of these (plasma speaker and flyback driver) is the flyback transformer. These can be found in old CRT monitors. I have at least 4 of these, thinking maybe my trasformer was blown.

Here is what I am trying to build now: I want to make the arcing as seen in this video

This was my step by step guide to building one. I have created a replica of this design except for the fact that I could not wire the feedback through the flyback but had to manually loop it around the outside core. This is also a good place to look, I am doing this exactly http://www.powerlabs.org/flybackdriver.htm (with the exception of using 270 ohms instead of 240)

If I forgot anything, please look in the comments on my original video and it will hopefully answer your question.

Thanks again
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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You say you're using a 2N3055 and none of those schematics appear to use a BJT. All use mosfets.

What is the schematic that corresponds to your circuit? OK, now I see it.

The easiest thing to try is to reverse the wires coming from your feedback inductor.

This is a really nasty type of oscillator and can easily damage your transistor. Given the low gain of the 2N3055 you're going to have trouble. Another possible problem is that your feedback inductor has too few (or too many) turns, or is not wound around the correct place.

Or you've killed the 2N3055...
 

Mitchekj

Jan 24, 2010
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I have to ask...

For the coil you wound, are you using enameled wire? If you're just using bare copper and it's touching itself, you no longer have a coil.
 

55pilot

Feb 23, 2010
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Evert time I think my opinion of industrcutibles has hit a low, I find gems like the following that make me realize that my opinion of them was actually too high. This is from first instructables page linked above "http://www.instructables.com/id/Buil...p2/Schematics/":

I get a lot of complainants of this project is not working very well or at all. This new design WORKs, however, for most people it may not work. This is due to the MOSFET (and some other components) is poor quality.

I just recently found out that manufacture who makes the components sell the best quality ones to other manufactures and sell the poorer quality ones to the whole sellers and retailers. For this project, the best grade MOSFET's is critical, and it can only be gotten by salvaging old electronic devices, unless you are willing to pay for thousands of components for the manufacture... :)

This guy needs to be on late night AM radio show talking about conspiracy theories, chem trails and being abducted by aliens.

I am beginning to wonder if the whole instructables website is one giant joke to see how many people it can get to jump through all the hoops or do really wrong tings for some sicko's enjoyment.

I would strongly disagree with the website you got your schematics from. THIS CIRCUIT CAN KILL YOU. Yes, you may get away with just a nasty burn most of the times, but the circuit does have the ability to kill you. Where I agree with the website is that this circuit is a "project for someone who is already familiar with High Voltage" Are you? Also, how old are you?

---55p
 

Mitchekj

Jan 24, 2010
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Oh wow, I didn't read that. That explains all of my heartache throughout my electronics career: I buy the parts and don't salvage them. Wish I knew that 10 years ago.

What is this 'instructables,' anyhow?
 

55pilot

Feb 23, 2010
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What is this 'instructables,' anyhow?
From the website: "Instructables is a web-based documentation platform where passionate people share what they do and how they do it, and learn from and collaborate with others. The seeds of Instructables germinated at the MIT Media Lab as the future founders of Squid Labs built places to share their projects and help others."

Unfortunately, with no adult supervision and with anyone allowed to post whatever they want, you get some real bad stuff. The quote above is one example. You will find instructions on how to make a LED flashlight by connecting 2 AA batteries to a LED! There is some good and interesting stuff there, but there is way too much crap and downright dangerous stuff that misleads those who lack the knowledge and background to separate the junk from valid information.

The scariest part is that it claims to be affiliated with MIT. I am embarrassed knowing that.

---55p
 

djrobotfreak

Apr 14, 2010
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Thank you for all of your help. I do know that this circuit can kill me and am taking precautions against doing so. I have been able to complete the circuit. I was using too thin of wire to create a high enough voltage. Yes I was using enamled wire. Unfortunately I have a new problem, since I (soon after I got it working) blew the transformer. Actually I blew two of them. I still have at least 2 more coils but I would be alot happier not blowing any more up. I am now wondering if I could just add more resistance to lower my Voltage in, therefore not blowing my coil?

Instructables can be a great site for people who do not know what they are doing. Unfortunately there are not enough sites on the internet with easy, begginers guides to electronics. I have had alot of problems just creating this simple circuit, mostly because I am only a junior in highschool, and only had a simple electronics class (which is all they offer).

Once again thank you for your help
 

55pilot

Feb 23, 2010
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Instructables can be a great site for people who do not know what they are doing.
So they go there and find the rubbish I quoted above. Unfortunately, as a beginner you and other in your position are unable to distinguish between the utter crap that some people post there and valid information. Not your fault, just the fatal flaw in the "community will collectively do the right thing" model that some people living in an alternate reality are pushing.
mostly because I am only a junior in highschool, and only had a simple electronics class (which is all they offer).
Unfortunately that does not make you qualified to be working on the type of dangerous stuff you are doing. Do your parents realize that you are trying to build things that can kill you?

Because of your level of experience, your age and the dangerous voltages you are playing with, my advice is to STOP WORKING ON THIS PROJECT BEFORE YOU INJURE OR KILL YOURSELF OR SOMEONE ELSE. I am not discouraging you from learning about and getting involved in electronics. There are much less dangerous ways to get involved in electronics and much safer projects for you to gain experience on.

---55p
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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how are you blowing up the transformer?

Are you using a small battery like the one suggested on that instructables (I think it was) page? Or are you using something larger?
 

55pilot

Feb 23, 2010
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Are you using a small battery like the one suggested on that instructables (I think it was) page?
Oh Steve, the eternal optimist, always hoping for the best from places like instructables, only to have his heart broken :).

Here's what the instructables article says in Step 11:
While I was testing (well, playing) my plasma speaker, the 12v battery is going flat and the arcs are becoming unimpressively short. So I replaced the battery with my lab PSU I modified from an ATX PSU and put an 22,000uF capacitor in parallel with its 12v output and ground.
Hopefully he is using one of those high quality caps from the junk pile and not buying a crappy new one. But wait. You are not going senile. Your memory is intact if you remember reading something about a small battery. That was in Step 4 (emphasis added):
* 12v power source (for TL494 oscillator / I used a 9v battery)
* 12v to 40v power source (for the flyback transformer)
So yes, he was talking about a small battery, but just for powering the control section, not for driving the load. He was still suggesting up to a 40V "power source" for that.

---55p
 

djrobotfreak

Apr 14, 2010
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Yes, my parents do understand that I am working with something that could possibly kill me. I know the risks and am acting accordingly. I have been looking into this for quite some time (since September 09) and know enough about this project to not get myself killed.

I know that the instructable's version is too simple to work well. Soon after researching into it I found that everyone had much higher marks about scopeboy's circuit. I am using a 12 V 1.3AH battery, that I bought from the local electronics store.

Right now all that I have working is a very simple circuit. Im thinking that the reason I blew up my transformer is that I drove too much voltage through it. I am currently buying parts off of digikey, since I think I blew my last mosfets. Do any of you know a better transistor than a irf540 mosfet.

STOP WORKING ON THIS PROJECT BEFORE YOU INJURE OR KILL YOURSELF OR SOMEONE ELSE

55pilot, please, I came here looking for help, not an argument. I admit that I do not know exactly what I am doing, but I know enough to get by if I have to. If anything, Im asking you to help me keep from killing myself. Have you ever build, tested, or designed anything similar to this circuit? Please, if you have any information on the topic let me know. Otherwise please stop lecturing me.
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Yes, my parents do understand that I am working with something that could possibly kill me.

Bwahahahahhahaha

Oh that was good. Honestly, we do hear some porkies from time to time, but that's got to take the cake.

I'm half considering suggesting you send your parent's phone number to 55p and let him call them up to make sure.

I know the risks and am acting accordingly. I have been looking into this for quite some time (since September 09) and know enough about this project to not get myself killed.

oh, stop it. You're killing me.

For the most part, your posts indicate exactly the opposite. That is, you lack the most basic understanding of electricity (let's not even talk electronics yet)

I know that the instructable's version is too simple to work well.

Why?

Soon after researching into it I found that everyone had much higher marks about scopeboy's circuit. I am using a 12 V 1.3AH battery, that I bought from the local electronics store.

Search does not equal research. I know it's just 2 letters, but the meaning of the word is quite different.

Right now all that I have working is a very simple circuit. Im thinking that the reason I blew up my transformer is that I drove too much voltage through it. I am currently buying parts off of digikey, since I think I blew my last mosfets. Do any of you know a better transistor than a irf540 mosfet.

And here is one very basic concept. I urge you to consider again what may have caused the transformer to fail.

Perhaps you should try to find specs for the transformer, or at least some parameters of operation as defined by a well designed circuit (like the original monitor you pulled it from).

55pilot, please, I came here looking for help, not an argument. I admit that I do not know exactly what I am doing, but I know enough to get by if I have to. If anything, Im asking you to help me keep from killing myself. Have you ever build, tested, or designed anything similar to this circuit? Please, if you have any information on the topic let me know. Otherwise please stop lecturing me.

55p may not be posting the most welcoming and friendly messages, but his posts will serve to warn other people from doing the same thing that you're doing. I think I'll leave them if just for that.

If by knowing enough to get by you mean that you know enough to copy a circuit from the internet without any understanding, then I guess you do.

I have a slightly more charitable view of instructables than does 55p. I have found some really useful ideas from there, although there is a *huge* amount of dross. With sufficient knowledge you can pick one from the other, but you are a fine example of someone who does not yet possess either that knowledge or the understanding of the finality of death (which in many cases is a possible -- and universally unwanted -- outcome) to be able to do that. In your case you have been fortunate that you have managed to kill components before they kill you.

As an example of your foolishness, you start with a circuit that is relatively safe, being powered from a 9V battery, and convert it to use a 40V bench power supply. Then (and believe me this is worse) you start using a lead acid battery.

One of the really cute examples you gave us was of a person drawing arcs from a flyback transformer. Several things were really funny.

1) Suction cap
2) Description of the switch (and the switch chosen)
3) The soldering skills
4) The description of the transistor
5) The description of the primary, er um, secondary, er um coil

But what was really amusing was the apparent use of both hands to draw the arcs. Now when I say amusing here, this is amusing in a totally different (and far darker) sense.

If you think that video gives useful advice on ANYTHING then you are severely deluded. Its only saving grace is that it probably won't kill you.

I would (probably) be highly amused to hear the precautions you're taking to prevent electric shock from high voltages. Would you like to detail them?

If you can impress on me that you understand what safety precautions to take, and I believe that you are actually observing them, then I won't close this thread. Otherwise it really looks like it's getting really close to the time to close it.
 
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