I can haz sparks? -- The CFL flyback driver [Published]

KatzenklavierKatzenklavier Regular
edited June 2011 in Life
Since all you lazy fucks didn't want to build a ZVS driver, here's a way to make high voltage easier.

First you will need a flyback. These are the transformers that make the high voltage in CRT displays. [The big heavy glass ones]. The flyback will look something like this. You can remove it from the circuit board with a blowtorch; simply apply the flame to the solder and it'll come right out. Don't worry about burning the board.

Now you need to identify the primary coil of the flyback. On the bottom there will be a semicircle of pins. To identify the primary coil, use a multimeter to test the pins. When you find two pins that measure about .5 to 2 ohms, that's your primary coil. Mark those pins so you don't forget.

Now you need a CFL. A compact florescent lamp is one of those swirly lightbulbs. Get a big one, the bigger it is the more powerful your driver will be. They are usually anywhere from 14 to 60 watts, but once more, the bigger the better.

Step one is to crack open the CFL. Try not to break the bulb, you just want to crack open the plastic. Inside you will find the driver. It will look something like this. This is the circuitry that supplies few hundred volts to the light bulb.

Now all you do is wire it up like this;

PoXUl.png

That will provide the transformer with the high voltage, high frequency AC it need to run. If all goes well then a few thousand volts will come out of the red wire. But to use it you will need to find the high voltage ground. The easiest way is to just bring the wire to the pins and see where it sparks to, but then you risk killing the CFL driver. A better method for finding the HV ground is here. If you don't have a 24 volt power supply, use 3 9 volt batteries in series, or two car batteries in series.

If you're lazy you can just arc to the flyback's pins, but once again you risk killing the driver. Use a rubber glove or plastic tweezers when handling the thick red high voltage wire!

Once you find the ground pin, solder a wire to it. You now have your high voltage supply. It's safe to handle the ground wire with your bare hands; it has no potential.

If all goes well you should have;


Is something not working?
A)You wired it wrong, or your driver has a different wire config. Try different combinations of wires.
B)If none of the 8 possible combinations work, then you have a protected circuit. These circuits shut off if they don't sense a lightbulb. This is easily defeated by placing a high voltage capacitor (400+V) across the two unused wires. You can get those at radioshack cheaply, and any value will work so long as it can handle more than 400V.
C)If that didn't work, try connecting the capacitor between an unused wire and one of the used ones. Try the 4 possible combinations.
D)If none of that worked, go get a different CFL.

Comments

  • KatzenklavierKatzenklavier Regular
    edited November 2010
    Ok then don't read my damn guide.
  • HellishHellish Regular
    edited November 2010
    Cool. Interesting setup but I would add a warning about getting the flyback.
  • DaktologistDaktologist Global Moderator
    edited November 2010
    this is awesome, i just tried it with an fbt from a broken plasma globe and the driver from a 230v cfl and it works perfectly apart from the small arc it produces (around 2 to 3 mm)
  • KatzenklavierKatzenklavier Regular
    edited November 2010
    Sweet. Get a monitor flyback, it'll work better.
  • DaktologistDaktologist Global Moderator
    edited November 2010
    Sweet. Get a monitor flyback, it'll work better.

    i forgot about the broken crt monitor in my shed that i found half buried in the garden when i moved in, just tested the fbt and it still works fine. defiantly creates better arcs compared to the plasma globe flyback transformer. the driver obviously doesn't like being open circuited judging by the sound it made when the wire to the fbt came loose
    P1020297.jpg

    Plasma globe FBT
    P1020300.jpg

    Arc
    P1020285.jpg
  • KatzenklavierKatzenklavier Regular
    edited November 2010
    Hungry for moar power? Then

    A) Get a bigger CFL driver
    B)Go for the gold.
  • DfgDfg Admin
    edited November 2010
    Awesome. I am going to publish this.
  • edited November 2010
    God damn, that's some awesome stuff. I wish I could come up with these kinds of things :D
  • DfgDfg Admin
    edited April 2011
    Taken from: Resistance Is Futile
    CMS Status:
  • DarianDarian Semo-Regulars
    edited May 2011
    Hungry for moar power? Then

    A) Get a bigger CFL driver
    B)Go for the gold.

    Well I think if you find a ballast from those big fluorescent tube style lights instead of a CFL you could have a lot more power and if you need to find some you could go to the dump or some where else to get one
  • DaktologistDaktologist Global Moderator
    edited May 2011
    Darian wrote: »
    Well I think if you find a ballast from those big fluorescent tube style lights instead of a CFL you could have a lot more power and if you need to find some you could go to the dump or some where else to get one

    it would have to be from a modern electronic fluorescent lamp fitting, the old style magnetic ballast wouldn't work
  • MarineBoatMarineBoat Regular
    edited June 2011
    1. Multimeter to find the windings on the flyback.
    2. 1kv+ 0.001-0.01uf cap between A and B and another between C and D. Useful in some cases to 'trick' the inverter into thinking there's a bulb.

    Also, in my experience these drivers burn up fuck fast. I wouldn't hurt to jack a few NPN transistors from, say, an old PC-AT power supply (bear in mind not all use the same topology) and replace the little pieces of toast on the board.

    You're better of with the Mazzilli driver or using a 555 or a TL-494. These have the bonus of allowing you to screw with the duty cycle.
  • KatzenklavierKatzenklavier Regular
    edited June 2011
    The mazilli driver is indeed a nice one, however nothing beats a mosfet full bridge when you want a mixture of versatility and power, even if the mosfets tend to get smoking hot when not driven ZVS or ZCS.

    Fucking miller capacitance.
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