The Plasma Speaker

Step 5 Build the prototype on the bread board

Do what the title says... Build the circuit on the bread board!

Why on a bread board and not build it directly onto the veroboard?

Well, it is a very good idea to build the prototype on the bread board before you solder the components onto the veroboard because...

• You will get a better idea on how to build a 'real' one on the veroboard.
• You can make sure all the components are working fine, if not, you can replace it easily.
• You can modify or tweet the circuit a bit to give the plasma speaker a better performance.

I built my circuit using my simplified schematic on the bread board that is connected to the "Electronic Lab" kit that I got a long time ago.

To connect the flyback transformer to the circuit, wind 5 or more turns of thick solid-core wire on the ferrite core. That will be your primary coil.

Comments

[Dutch_Razor]

Looks like a very nice idea,the sound is good too!

Wouldn't it be much easier to drive the MOSFET with a micro controller though? You'd pretty much only need 2 components (aside from the flyback stuff).

[jbryan]

i went to that site and looked for that flyback transformer but idk specifically what specs it requires can you help me out with that?

[amizzy55]

Hi plasmana,
im 16, a junior in high school, and i decided to do your plasma speaker experiment for my science fair project. i brought the idea with all the info to my chemistry teacher and she said it was the most incredible thing in the world. she agreed along with another school science teacher to help me out with it. i have ordered all the parts u have specified and now im just waiting for them to all arrive. im just wondering do you have any tips or helpful pointers to keep me from screwing this thing up? thanks!

[coilsinamotor]

can i use a 555 for this??

[mattandphil]

 We have built our circuit exactly as shown in the schematic, yet we are not getting ANY result through the flyback.  No arc, but we know voltage is flowing through the primary, any thoughts on what is wrong? is our flyback broken?

[SkyKid90]

I finished building my prototype, but just producing a buzzing annoying noise, I need some guidance here, and with how many volts should I work, 12 or 9?

[randomapps]

 try using a battery wall transformers aren't true dc 

[Zolmeister]

 12v........

[htc109]

 does increasing the number of turns effect the output or something?   and the primary voltage?,- shoud it not be A.C??.      how much voltage and amperes should be in the primary, n can someone explain how to connect the primary voltage properly, as soon as possible!!!

[BIGHAIRYDUDE]

how far apart should the arc wires be?

[BIGHAIRYDUDE]

can you just keep the circuit on the breadboard or will it get too hot?

[jaredtkatz]

 My flyback has both the high voltage out as well as two other, thinner cables: a red one and a black one.  What are these for? Do I jump the current from the high voltage out (thick red) to the black cable (ground) or do I need to find the ground pin?  Are these two other cables not even necessary?  Thanks a lot!

[rafic1]

 Yeah, I'm having the same issues, can anyone help me?

[se00an]

Amazing project, I ave never worked with a flyback before, although I have a few lying around. I see the top high voltage output wire, but what connects to the other end of the spark gap, is it one of the many leads on the bottom? Would you possibly be able to include a picture of your active flyback circuit? Thanks! Sean Michnowski

[Plasmana]

If you never worked with flyback transformers before, you should start making simple circuits before you build something very complex.... The schematic below shows a very simple flyback transformer circuit.

[se00an]

I will try this circuit, but for the primary coil, which is better to use: should I wrap wire around the ferrite core, or is it better if I just use the two primary coil pins on the bottom?

[Plasmana]

It is better to wrap your own wires around the ferrite core.

• Feedback: 3 turns of wire
• Primary: 5 turns of wire

[Xellers]

When I built a 555 timer flyback driver, for some reason, the coils I wound produced about a millimeter of spark every few second, but when I used the internal primary of the flyback, I always get at least an inch of big fat spark. What can you suggest? I used 14 Gague wire from a microwave power cord. They are VERY thickly insulated. Could that be the problem? Please help.

[Plasmana]

The insulation does not affect the wire at all, only thick(ish) solid core wire will work very well for the flyback transformer. If the wire is thin and/or multi stranded, it will not work very well.

[moshee]

By "thickish", what exactly do you mean? could you give a AWG estimate? would 20 AWG mag wire work?

[Xellers]

That could be the problem, and unfortunately, I can't find any old TV sets, so I have a modern flyback with a focus divider :(

[Plasmana]

I have the same problem, I ONLY have the modern flybacks with focus dividers in them too, everybody else seems to have and old flyback or more... I cannot find any old TV sets, the good stuff is getting rarer and rarer as more people becomes DIY'ers.

[Xellers]

I thought I saw older flybacks with diodes, but no dividers in your slideshow... The real problem that I'm having is not that there are too many DIYers using old television sets, but that everyone is throwing away TVs, just not of the right age :( But even so, you can build a Tesla Coil with one of these newer flybacks.

[Plasmana]

Ahh, yes, I forgot, I do have an old blue flyback with only a diode, but it does not work well... Yeah, all of the good stuff is going down as the new age of microcontrollers are coming in, and they are completely useless to many DIY'ers...

[Korey]

What if your own wire wont fit? theres not much gap between the ferrite core and the the transformer body

[Plasmana]

You can use enamelled wire, they have extremely thin insulation.

[Tristian_Lyons22]

hello, when running more IRF540's in parallel, do i need to have a diode for each MOSFET, or is just the one included in the schematics ok? thanks!

[twist2b]

The diodes INSIDE the IRF540. Google "IRF540 datasheet" you will understand. Why would you run more IRF540's in parallel though? If you do that, your splitting the Amperage. That could be bad.

[Tristian_Lyons22]

my intent behind the running of the MOSFETS in parallel was to reduce the amperage to each one, therefore stopping them from blowing due to overheatedness. for your comment above, are you telling me that the diode in plasmana's schematic is not needed at all because the mosfets are internally dioded? the UF 4007.... that one. (sorry about this, im new to mosfet chips.... but pretty experienced in small elecrtonics)

[twist2b]

http://www.datasheetcatalog.org/datasheet/stmicroelectronics/9387.pdf
Look, its internal... the WHOLE POINT of mosfets are to give square pulses. This is possible because of the diode inside it and the electrical switch.

To lower Amparage you could use a larger resistor value. But the amperage is NOT the only issue. Too long to explain, but there is just too much stress on the mosfet in this schematic. I created the original, the stress is halved... so mine is fine.

You CAN add a diode... I feel I should add this.
However, there is no reason to... theirs already a diode IN the mosfet.

[saboo4800]

hmm hello good sir, you seem to be very well informed hmm and i was wondering, where is this original schematic that i've seen you speak about so often? hmm i'd like to have a look at it myself hmm is it what plasmana talked about with scopeboy?

[twist2b]

http://scopeboy.com/tesla/flyback.html

He posted it, but w.e. Yeah, its actually old. Steve has posted more recent ones that are better (I recommend an AC circuit, audio is usually better.)

If you do use that schematic make sure R5 and R11 have a higher amp rating.

4hv.org
Feel free to ask questions there... the author is actually a MOD there :)

Good luck with your project, I had alot of fun with mine.

[navyseal51009]

Quick question, on your flyback you only have the one lead, not counting the secondary coil you wound. On my flyback, taken from an old crt, the transformer has four leads, two for primary and two for secondary i'm assuming. Can i use the primary leads that are already attached or do i have to wind my own? Another thing, does the spark go between the two secondary wires or from the red lead to ground? And how do i find which leads are which? Thanks.

[izidor7]

hy

You could use the primary that alredy is there, but it has like 30 windings.... so it would be better you would wind a new...

There is One secendary and it has one wire Red thick... the older ones don't have a rectifier but the newer have.. and the other wire is gnd some pin on the bottom.... and if it has no rectifier then you can mesure the resistance... you could get like 70 Ohm.... or so.. but those with diodes and cups in them(the newer ones) you can't mesure...
_{Also you have a fiew more secenderis.. and they have much less windings compered to the secendery you use for hv. and you don't use them.... becose the voltage is verry low.. like 100V... or so.}

you need the red thisck wire.. and the gnd.. and if you use the primary on the flyback your hv will be lower.. because of this it is better to wind 5 turns of wire on the core...

[navyseal51009]

Ok, thanks, so does that mean the other wires aren't to be used in the final design? And then how do i find the ground pin if my transformer does have a rectifier with diodes?

[izidor7]

just leve. the pins you won't use...

as for the gnd pin_{, take the red thick wire. and move it neer the pins.. (ofcors you would need to turn on your driver for this ) and from witch pin you get the longest arc.. use that.. solder a wire on it. and use ti.. and the other connector insulate ... with hot glue or something else...}

It would be nice if you could ground that wire... but separate from the driver....

[navyseal51009]

Thanks again, hopefully just one more question, I tried to find the ground pin for the secondary coil as you described except it didn't work, I'm wondering if I have a bad transformer... When trying to find the ground pin on the bottom do I apply power to the original primary or the primary that i wired? And how much power is enough? I tried 15 volts DC and got nothing except a buzzing noise from the transformer. thanks

[izidor7]

it could be that the flyback is broken... it's posibal... one posibility is that the freq is too low... but then you would get a flappy arc., so that it's more awius that the flyback is broken... You say the flyback is buzzing??? can you hear sonething felese from the flyback??? it is normal that it buzzes.. but the secondary should give you a arc.... i had a fiew broken flybacks.. and you can throw it into the trash can.. but leave the core, you might need it, and ofcors the red cable... The red cable is verry good insulated.. leave it for the gnd wire for your next flyback, it's hard to find so good insulated cabels.....

[majorkuso]

If I read the schematic right your ground is electrical ground correct or to battery or adapter( voltage source).? also where is the secondary on the flyback, that would be the HV pin aka the Aquadag connector(suction cup) and bottom ground pin on flyback correct?

[Gasburner]

it's the voltage source ground :D