The Plasma Speaker

Step 4 What you will need...

You will need quite a lot of stuff to make the plasma speaker...

Parts:

• TL494 chip (Datasheet for TL494)
• 200uF (or 220uF) - 50v electrolytic capacitor
• 47nF - 250v (or similar voltage ratings) capacitor
• 100nF - 50v capacitor
• 10nF - 50v capacitor
• 2.2K - 1/4W resistor
• 10 ohm - 1/4W resistor
• UF4007 diode (or other fast diode that is rated 1A (or more) and 500v (or more)
• 10K - 1/4W potentiometer (same thing as a variable resistor)
• 22K - 1/4W potentiometer (same thing as a variable resistor)
• Audio jack
• Wires
• IRF540 MOSFET (other MOSFET's with similar ratings should work)
• Large heatsink
• Flyback transformer (can be found from old CRT.)
• 12v power source (for TL494 oscillator / I used a 9v battery)
• 12v to 40v power source (for the flyback transformer)
• Breadboard (for testing)
• Veroboard

I bought most of my electronic parts from Farnell.

Tools:

• Soldering iron
• Wire strippers
• Wire cutters
• Pliers
• Helping hands
• Hot glue gun

Abilities:

• Good with a soldering iron.
• Can read schematics.
• Know what you are doing when you are dealing with high voltage.

Comments

[Mythx20]

Does anybody know the wattage rating of the components used? I'm an Electrical Engineering Technologist student and I'm trying to purchase the correct parts, but the wattage rating of the potentiometers, capacitors and resistors aren't listed. 1/4 Watt? possibly 1-3 or 4 watt?

[Plasmana]

I have edited step 4 to give the information you require. :)

[Mythx20]

The only other question I have is the size of the wiring you used. Was it 18 gauge? same with the size you used to wrap around your ferrite core

[Plasmana]

It is 16 gauge.

[Mythx20]

It seems a 47uF 250v capacitor is extremely hard to find, even on Farnell. I'm assuming the 10 and 100 nF caps are disc ceramic, through hole. Can anyone point me in the right direction for a 47uF 250v cap?

[rocket master]

Camera flash

[arianen]

I've been looking around at all of the websites mentioned in the comments, but still haven't been able to track down the 22K potentiometer. If someone could give me a link to where I can buy it, that would be great!

[nreading]

http://uk.farnell.com/jsp/search/browse.jsp?N=731+2031+202462&Ntk=gensearch&Ntt=22K+potentiometer&Ntx=mode+matchallpartial


and

http://uk.farnell.com/jsp/search/browse.jsp?N=731+2031+204275&Ntk=gensearch&Ntt=22K+potentiometer&Ntx=mode+matchallpartial

might be what your looking for

[lynchpman]

I have an IRF630 MOSFET. Would that be considered a "similar rating" and work instead of the IRF540?

[dancsa]

Hello
I looked into the IC datasheet, it says, Vcc can be up to 40 V... Why is it 12V and not powered from the same powersource as the flyback?

[Erty_W]

I have no fast diodes rated more than 500 V, but instead one rated for 200 V and the other rated for 400 V.
Is it correct that I may put the 200 V diode in parallel with a 10 megaohm resistor, the 400 V diode in parallel with a 20 megaohm resistor and then connect them in series instead of a single diode rated for 500 V?

[Tristian_Lyons22]

would a 1N4007 diode work? i had a UF4007, but it did the reversal thing that diodes do when they die. i have liek 10 1N4007's laying around though.

[Plasmana]

It should work, but less efficiently...

[Tristian_Lyons22]

what about a 1N5404? better or worse than the 1N4007. i dont know much about picking diodes out, so sorry for all the questions

[Plasmana]

Yes, the 1N5404 diode would work better than the 1N4007 diode.

[randomapps]

 i have heaps of germanium diodes everywhere would they work for this?

[-max-]

they will burn out almost instantly. they uswaly olny support less than 1A and less than 60V

[marteloficina]

I could use a transistor instead of IRF540 2N3055?

[-max-]

yes. make sure you have a heatsink and a small value resistor between the base and the output pin from the chip

[melkior34]

I think you have used the 2N3055 to built the simple dirver ? I have done this done..It works too fine ! But you must use the IRF540 here for its caracteristic.

[ARJOON]

no dude it 9will fry in3stantaneous3ly i think

[kumaraman]

Hey Plasmana, i am really interested in this project, i just cant source the correct TL494 with the same specs. I was wondering if this was ok.
http://nz.element14.com/texas-instruments/tl494cn/switched-mode-controller-dip-494/dp/1106036

if not could you direct me somewhere i could find this

Cheers

[harryn81]

Yes.kumaraman go for it,the given tl494 ic is correct for this circuit.
Good luck.

[seabeepirate]

So correct me if I'm wrong, but assuming that you've salvaged the flyback mosfets and power supply, this actually looks like it's a project that can be built for less than $20 USD?

[htc109]

 can anyone give me advice on a good enough power source or atleast how to make one using some kind of batteries or power adapters????

[bcantley2010]

a car battery will work

[kisalvador]

havent tried it yet, nor have i built this plasma speaker, but i do know car alarm transmitter batteries are rated at 12V

 http://www.radioshack.com/product/index.jsp?productId=3538773&clickid=prod_cs

radioshack isnt the best place for components but batteries should be fine lol

[Plasmana]

You can use a car battery...

Power supplies are not recommended as they have 'noise' in the lines, it will interfere the performance of the plasma speaker.

[randomapps]

 i have a power supply which is 30v would a capacitor to filter the noise?

[bcantley2010]

3 12 volt batteries in series would give you 36 vdc with less ripple. if you have a o-scope you could always take a look at the ripple with the power supply you currently have.

If you use a oscilloscope's AC coupling setting it will reject the supply's DC and reveal any ripple

[Blue_Bird]

I cant seem to find a 22k potentiometer online on the website I'm buying the parts off of, The closest I could find are 20k and 25k , which one should I get?

[ElmerHomero]

The 25K should work fine

[knoxarama]

are there any devices you can scrap to get a tl494 so buying isn't necesary?

[Plasmana]

You can find TL494 in a OLD desktop computor power supply.

[sipes216]

plasmana, here's a pretty good Q i have for you. the "12v to 40V power source" you specify. what exactly are you using here? are you using two power sources, one for 12v, and another for 40v? i'm not exactly sure what is meant by this.

i've got the board completed, but i'm just waiting on a mosfet to arrive at my local electroics store along with the nte1729 (nte version of TL494).

also, on the flyback, for the windings, is it possible just to use a bare ferrite core and make the needed primary and secondary windings on either end of the unit?
i managed to score an old magnavox ferrite core.

[electricfan]

when he says 12-40 he means you can use voltage form 12 to 40. You could do that but do you know haw hard it is to wind over 2k turns?

[sipes216]

thanks for the reply! and i suppose i could just find a good transformer to carry it over, and tie that to the 12v i suppose. and what i was talking about in regard to the ferrite core was not winding the thing myself for volt conversion, but i was talking about the coil required as the flyback. there is the main loop coil left on there. 3 wires, all connected to the same. i had planned to use this as the secondary for the actual arc.

[electricfan]

sure that will work fine the middle wire is probley a center tap

[davydo2]

Hello, ok, I have found  a flyback trans fome a old tv. But insted of winding 5 or so tunrs on the ferrite side for the prmy could i gust use the one already bult in I have found the correct pins for prmy secon 0volt pint ect. or will there not be the correct  voltage on the seconary windings.   

[thescroll]

When you say "large heatsink," what size range do you mean?