MAKE A HIGH VOLTAGE SUPPLY IN 5 MINUTES

Step 1 Some Info on CFLs

CFLs can come in a variety of shapes and sizes. Generally the bigger the wattage the larger the voltage output. For this Instructable I got a 65 Watts light bulb.

Most CFLs have a similar circuit topology. All of them have 4 wires coming out of them. The wires are in pairs, and each pair connects to a filament inside the light bulb.

The CFLs I came across have the high voltage on the outer wires. You only need to connect the outer wires to the primary coil of the flyback transformer.

You will find a comprehensive description of CFL circuits on this page

Comments

[Evilthingamabober]

Does the CFL put out AC or DC? And could it be used to drive a Cockcroft-Walton generator?

[spycept]

actually a cfl has a bridge rectifier built in to it taking the ac from the mains to dc and uses the transistors to pulse the dc, then the resonating capacitor and inductor take the 45 or so volts (the diodes take half the voltage then the capacitors take out more to smooth the rippled dc) and step it up to 900v or so. so in the end your getting 900v dc pulsed at whatever CFL's run at, and i beleive they are fairly fast as cfls are designed not to "hum" or to visibly flicker.
as a whole i think this is a extremely easy was of driving a flyback then making a whole circuit as this is really just a more complex miniature version of those anyways. i could only get a hold of a 40w CFL that i would use for a plasma globe (i have a old AC flyback) and it would last for about 20 seconds before almost overheating. but i ordered some heavier duty transistors as that is what seems to be what goes out. i am going to try to hook up them where the old transistors were (that eventually blew), but i accidentaly hooked them up bacwards and tripped the main breakers haha takes lights out to a new level.

[Biotele]

That's awesome. How did your plasma globe look like?

[spycept]

it was VERY strong with a 3" clear globe lightbulb (while it lasted) as of right now im waiting for my only store within 300 miles to get more CFL's in stock as i burned up my last 40watt one. and then i can try my new transistors in them with big heatsinks to hopefully be able to run them longer without burning up. it seems that the transistors are the reason for mine blowing. as how a CFL actually works is by have a high voltage to heat the filiment and start the arc, but after the arc is started the resistance across the tube lowers dramaticly so the resonant capacitor and inductor makes less voltage (or current im no electrical engineer xD ) so this puts less stress on the transistors after the "start" cycle. this is why you should always change the lightbulbs when they go bad in regular flourescent lighting, as the ballast is essentially stuck in start mode putting out the full current and voltage reducing the life of the ballast. Once i get another big CFL i will post what results i have with the new transistors.

[Idonet]

Since the output stage goes into a transformer I am pretty sure it delivers AC.

[emcelhannon]

Great instructable. I got a nice arc with a 60w cfl and a pretty small flyback.,(1.5 inches). I also managed to keep a smaller cfl from blowing by leaving the flourescent tube attached. I noticed on another instructable that you can make an arc work like a speaker using ic timers. I haven't had any luck with those, so naturally I'm trying to figure if there is a way to insert the audio signal into the cfl, and if so, where?

[Biotele]

That's Great! Can you post a picture or a video in the main page? Yes you can make a plasma speaker out of this setup. The easiest way is to pulse modulate the output. You either chop the feedback signal, or the input voltage.

[emcelhannon]

Thanks Biotele, I'll work on a couple of pictures and post them. In the mean time, can you give me more specific instructions on how you would hook the system up. I confess, I don't know the term "chop," unless you mean to cut the circut and insert the audio in a series.

[emcelhannon]

I've blown a few cfls now, so I'm going to try the incandacent light in with flyback. I'd like to see if I can repair the cfls. I'll need instructions on testing a mosfet or transistor. I'm also wondering what the black cylinders with the slight magnetic field are. Have you guys settled on a better method of driving your flybacks in the year or so since anybodies bumped this thread?

[andrius4669]

I see resistor in input of CFL. Did I need to replace it?

[-max-]

this CFL, CFL driver is an jackpot for making CRTs!!! the CFL circut is for driving the flyback and the lamp itself has phosphor that will be the screen!

i shall make CRT like these, http://www.sparkbangbuzz.com/crt/crt6.htm

will it drive an ignition coil??? or a TESLA COIL???    i think so!!!   *,*
                                                                                                                       U

[Marn1X]

You say you've used a 65w bulb for this experiment. Do you mean the light output of your CFL is the equivalent of a 65 watt incandescent, (thus a 12-15w CFL), or do you actually mean its a 65w CFL?

[Biotele]

It is 65w, equivalent to 300W incandescent.

[adalast]

300 watt equivalent... 65 watt actual.  got it at lowe's for $17.

[Marn1X]

Ok, thank you. I'm gonna try to make this when I get my CFL, already salvaged my flyback from an old TV :)

[Marn1X]

Awesome, I got it to work. I tried to use a single 2n3055 to drive the flyback and it failed, so this is a relatively simple solution. I used a 65w cfl and had to put a capacitor between the outer and inner lead, like you said.

Check out this vid i made.
http://www.youtube.com/watch?v=9pd1w63gaU4

I'm gonna make a Jacob's Ladder soon.
Thanks for the instructable, Biotele.

[Biotele]

WOW! That's even better than mine, good job!

[Marn1X]

Heh, I later found out that i was using the wrong pins on my flyback. When I found the right ones the arc was literally 10 cm long and flaming! After 5 minutes my CFL blew up :'( I know, I was taking it to the limit... One of the high voltage fast switching diodes blew up with a bang.
Anyway, I had a lot of fun while it lasted! Maybe I'll try to fix this sometime

[jlipimpski]

I just got mine set up, and tried to hook it up to a jacob's ladder. It works great when the rods are very close to each other (less than one cm), but anything that is greater than that causes it to start up nicely, but then fizzle out. The sound lowers its pitch, and the arc becomes less and less visible until it disappears. What is left then is a low, quiet hissing noise coming from the two connections.

I just re-read the instructable; i think this may be the issue. both leads to the flyback transformer are connected to the two pins for their respective polarites; so each lead is connected to the two pins for that end of the lamp. So i think the capacitor in between the two polarities may be causing the problem.

Thanks for the instructable; this was a whole lot cheaper and easier than trying to find/buy an NST.

[Biotele]

"so each lead is connected to the two pins for that end of the lamp"

I don't connect each flyback lead to two pins. It's 1:1, a flyback lead goes to a high voltage lead. Some CFL don't operate in this manner they need the current leaked by the filaments to start oscillating, So I put  capacitor between a HV lead and a filament lead in order that AC current flow through the circuit.

[jlipimpski]

Alright, i see what you mean there. I just fixed my circuit and connected the flyback leads to their corresponding high voltage pin on the CFL circuit, and now the power supply is working nicely. From the experience you've had with this kind of power supply, how long are these good for? do the components burn out relatively quickly?

[Biotele]

Thousand and thousands of hours of operation. Only a power surge or a short can destroy them.

[jlipimpski]

funny story about that, actually. I had it working really nicely, making good arcs. I decided to try to make the jacob's ladder wires better shaped, and accidentally moved the two apart too much. I turned it on, it didn't arc, and i went to turn it off. evidentally, I didn't reach the switch in time, and I fried a transistor (see picture, bottom left lead on the thing). I'm going to try to go out and find a better CFL--i just used the cheap-o one I had laying around. Great instructable, thanks again.

[Biotele]

I bigger powered cfl can sustain more current when shorted and therefore will have longer life.

[joey2point0]

Help i hooked every thing up correctly like it said in the video and when i plug it in nothing happens NOOO

[The Ideanator]

NOOO?

[nickglowsindark]

I understand that occasionally the lead configuration in the CFL will be different, but the one I got looks nearly identical to the picture you posted. By the end of the project, I wasn't getting a spark any longer than about 4 or 5 millimeters, and so I started troubleshooting. As far as I can tell, everything was hooked up properly- I'm confident that I identified the correct terminals on the flyback. I used a multimeter to check the voltage output of the CFL circuit (expecting it to go up in flames- the meter was only rated for 600V) and instead saw a value that started around 120Vdc and dropped as soon as I hooked up the meter (like a capacitor would have). I decided that I must've hooked it up to the wrong wires, but after checking voltages across all combinations of the 4 wires, the most I saw was a constant 120Vdc output across an outer and next-to-outer wire. What sorts of values should I be expecting at the "high voltage" leads? Do I need a different kind of CFL, or did I manage to fry something internal accidentally?

[Biotele]

Hmmm, You may have a fried CFL, The transistors are just passing along the voltages from the rectifiers. Do you know how to test a transistor? Or.. the circuit is not oscillating and you need to add a feedback capacitor like in step 4.

[nickglowsindark]

I ended up having to add the capacitor to get any voltage at all out if it, and I know how to test transistors, but I'm afraid it's a moot point now, since a little bit more fiddling around resulted in an interestingly colored flame and a terrible-smelling apartment. I'll be picking up a new one later today probably and giving it another go.

[surfies]

Thanks a lot for the circuit diagrams for the different CFL's, I've got another plan for these inverters, if it work i'll post it.

[Biotele]

my pleasure.

[xxfoxracer9xx]

would this CFL be a good one to use
http://www.lowes.com/lowes/lkn?action=productDetail&productId=46931-75774-017801997118&lpage=none
it is relatively cheap and i already have the transformer, also are the wires u soldered to the bottom of the transformer (the 2 that go to the CFL, and the ground) the same on all transformers, in other-words, are the pins on transformers all the same

[Steve Morgan]

Excellent Instructable, thank you. Will this system withstand an open circuit with no arcing? I need to create a 25KVDC-50KVDC field which does NOT arc (ever). Also, I have an old-style CFL module which uses a simple transformer and a traditional bulb type starter circuit... will this drive the television flyback properly?

[Steve Morgan]

Old style CFL picture attached.

[Biotele]

From the pic, it is apparent that the cfl uses a low frequency ballast and will not drive the flyback. Get a new CFL.

[Biotele]

If It is not an electronic ballast it will not work. If it is an electronic ballast, there should be a transistor in the circuit. Can you post a pic? If you just need a static field then you have to use this circuit with an HV capacitor. You would have to turn on the circuit for a short time until the cap is charged. And from time to time you will have recharge the cap, depending how much leakage you get. I am guessing that you need this for a lifter. In this case, the ionic stream is leaking more charge than a capacitor, so it is best to put a HV resistor in series with the cathode. The resistor should be high enough to prevent arcing but not to high to reduce maximum lift.

[kev717]

Hi, I tried building this circuit but when I turned the power on, instead of laughing madly, I was screaming like a little girl because the circuit from the CFL blew up... is there a way to prevent that from happening (or would a better light work)? I was using a 13 watt bulb purchased from the dollar shop for $3, so I think it may have been the bulb... and I've checked, the outputs and inputs on the flyback transformer were all correct and the transformer still works... I just need a new light I guess... sorry for the long comment and/or for placing it in the wrong place, this looks pretty cool so I'm not giving up just yet. -kev

[omnibot]

I think "screaming like a little girl" at an experiment gone wrong is almost as good as laughing madly at a succesful one.

[Biotele]

Lol! The CFl you got is poorly designed. You can prevent it from blowing p by putting an incandescent light bulb in series with the flyback. The lower the rated wattage of the incandescent light bulb the the more resistance it has. Higher resistance protects the circuit more but limits power of the HV output. There is also the possibility that you misidentified the primary coil pins. You can experiment more to find the correct pins while you got the incadescent light bulb in the circuit. Once you find the pins that gives you the biggest spark you can remove the incandescent light bulb.

[kev717]

well, luckily for me I had a camera trained on it so I've got a pretty cool video of a CFL circuit exploding... also, I'm certain that I have the correct outputs, I've tried it with a few AAs in series and it made my arm jump. Next time I'll probably put an incandescent lamp in series with the flyback.