build a singing arc (plasma speaker) (ongoing project)

this instructable will show you how to make a simple plasma speaker. 

a plasma speaker (singing arc) is a device that generates a high voltage discharge that emits audiible music. all the sound comes from the ark or plasma. 

How It Works.
in this version, we will use the magic of PWM to create audible sparks. 

astable 555 circuitry is the heart of the circuit. it makes a initial high frequency signal of about 18,000 Hz and the pulse with is controlled by the music source. this signal controls a high power transistor that turns on and off the power to the flyback transformer. this "oscillation" drives the flyback and the flyback's output spark will basically get thicker and thinner from the PWM and ultimately from the audio source.


its sort of like flipping a light switch ON and OFF. (just 18,000 times a second, easy!) and if you leave the switch ON longer than you leave it OFF, the light will be brighter than half. and if its OFF for longer than it is ON, the light would be dimmer. that's PWM's core.

now just flip the light switch on and off 18 thousand times a second, and control how long each pulse is in proportion with the amplitude of the mp3, output at any the given moment and now your light will dance to the music, (and the slight chance you break the light switch)

Step 1: All the parts

you will need:

● power supply  at least 3A.                    (SLA battery's work, or a plug in power supply capable (PSU) of 4A)

● heatsink                                                    (your mosfet will go POOF without it, and get a big one too, I use the heatsink that was an
                                                                              my power supply, and a fan)
                                        
● flyback transformer                                      (you can get it out of old TV's or online. the larger, the better,)

● high power MOSFET                                      ( find it online or one in the TV you found the flyback or online)

● 555 timer                                                          (you can get one at radioshack or 10 of them for the same price online)

● a 8-pin IC holder                                              (to make it possible to replace the 555 if it goes POOF)

● (2)  5K POT                                                        (i ordered both online,available online and local electronics shop )
 
● 0.01uF  ceramic capacitor                            (buy it online,local electronics shop, or in my case, junkbox)

● 0.1uF    film capacitor                                    (buy it online, local electronics shop, or in my case, junkbox)

● 0.47uF   electrolytic capacitor                     (buy it online, local electronics shop, or in my case, junkbox)

● high value (470uF) electrolytic capacitor  (buy it online, local electronics shop, or in my case, junkbox)

● PCB                                                                     (available online and local electronics shop)

● computer fan                                                    (a small computer fan i found in a computer power supply unit)

● wire                                                                     (buy it online, local electronics shop, or in my case, junkbox)

● duct tape  and electrical tape                       (for use to cover the bottom of the PSU and better insulate internal components)

----------------------------------------------------------------------------------OPTIONAL--------------------------------------------------------------------------------

● a housing for everything (i am making a custom wooden box as shown later in the instructable)
    * quartercut white oak half inch thick, 5 inches wide, and at least 3 feet (with some extra)
    * small brass wood screws
    * small screws with matching nut
    * wood finish
    * wood-working equipment
        * wood glue
        * belt sander, random orbit sander, and good old handheld sandpaper
        * jointer
        * plainer
        * router with 3/8ths inch rabbiting bit
        * table saw
        * box joint jig
        * drill w/ small drill but for the 8 wood screws and metal

  
● sheet of metal    (10 X 5 inch)


● metalworking equipment
         * something to cut it to size i used a dremel but i didn't get a good straight cut, so i cut a bit bigger and ground it down with a
              large stationary belt sander
         * drill press with various bits ranging from 1/16 inch to over 1/2 inch
         * sand-blaster
         * clear-coat


● indicator light  
 (I got myself one from online for a buck, but i replaced the inside ne2 bulb with a 5V light)

Comments

[crazy-blender]

will it kill you?

[-max-]

it has the same danger level as walking down a ladder.

if you don't know what you are doing, [not experienced with basic electricity and HV] it is dangerous and can seriously hurt you. however, if you use your common sense, play with van-de-graph generators and just get familiar w/ high voltage, you should be fine.

just attempting to walk on a ladder for the first time and triping and falling, breaking a bone or your neck. in the same way, this can hurt you by: Ventricular fibrillation, cardiac arrest, RF burns, shocks, boo-boos, etc read http://en.wikipedia.org/wiki/High_voltage
http://en.wikipedia.org/wiki/Electrical_arcing
http://en.wikipedia.org/wiki/Electrical_shock

[Morgantao]

Boo-boos are the worst! :D
Nice project. Gonna have to build me one.
How would you protect the setup from cats (or rather the cats from it)? Would a grounded metal cage do it?

[crazy-blender]

Instead of grounding it to mains ground hook it up to the flybacks HV negative. To find the HV negative I recommend this instructable: How to find the primary and the secondary coil of a Flyback transformer

PS keep it away from cats and babies :)

[-max-]

I guess you could add a kill switch. And not have cats in the workshop. Other than that I don't know

[Morgantao]

I live in a tiny apartment with my wife and four cats (and soon toddler). I can only dream of having a workshop.
My reasoning for a metal cage, as you've probably guessed, is a kind of a Faraday cage. I wouldn't wanna touch it and test it, but it *should* keep you out of harms way.

[-max-]

I would just keep it out of reach when your not using it. remember, this is more of a toy rather than something to replace computer speakers. (I wouldn't trust the circuit, the kickback might go far enough backwards to fry whatever you have it plugged into, such as a sony walk-man or computer.) (you wouldn't want to fry the computers sound card). or a Faraday cage, I would use a wire grid bent into a cylinder shape, glued over the top of the output, and cap it off with a circle cut out of the same metal grid.

[-max-]

Oh ok I see your situation. I dont know. there are other designs online for more pro-looking versions. I would just keep it out of reach without anyone around.

[TheEquazn]

You aren't using and audio input? If you did how would you hook it up?

[-max-]

good catch, thanks, radioshack 3.5mm jack and double stranded wire from something like a old unused power adapter, (that's what i used, anyway)

[Nicola Tesla]

Could the .1 uf cap be replaced with another valued one? my radio shack doesn't have any and nor does my collection.

[Nicola Tesla]

errr. I meant the .01uf....

[-max-]

for what part of the circuit, i use it a few times, in the 555 timer area, if you use another value, you may not get the right frequency needed to drive the flyback, so what i would do is build the 555 with the parts you have at hand and instead of a mosfet/flyback setup, use a speaker. if you can play with the POT's and get a super high pitched sequel that you almost cant hear it, then it should work. (or just use a frequencies meter, like an osiloscope or expensive multimeter)

[Nicola Tesla]

or could i just make it with a near value cap, and see if it works? or would it hurt parts of the circuit?

[Kiteman]

Do we get to hear it?

[-max-]

i made a video of it, but it was static sounding, although i could hear it well with my ears, i think the radiant EMF gote to the cameras sound track. ill see it recording it with another cam would work

[-max-]

im a bad speller, *got*