Testing a TINY little CCFL driver for laptop displays.

[@SianaGearz]

Good old Clive from the past who's always there for you when you hold a Chinese PCB in your hands.

[@xDR1TeK]

Hi Clive, I pulled out some tubes from an old plasma TV, I tried to fabricate a circuit using the transformer from the same board that powered those tubes. I keep burning transistors. It's drawing too much current. The transformer has 2 leads on the primary not center tapped. So for undue laziness I made a 555 timer to output 50% duty cycle, and connected the signal to a mosfet that pulls one lead of the primary while the other lead is connected to 12V. Added also a reverse bias diode as Snubber on the primary. The tube is lighting at one end and I have to raise the voltage to 30v to get the tube lighting properly. But current consumption would heat up the transistor and blow it up. So I added 2 of the same transformer as parallel on primary but in series on the secondary, again it lights up properly at 20v but current is at 1A DC. Transistor was a large package with heatsink and it gets too hot to hold. Any ideas about how to properly design such a circuit? What's the secret of ccfl tubes? Should I focus on pure AC signal on the primary? PS: 555 timer is powered from a 12v voltage Regulator.

[@bigclivedotcom]

There are lots of CCFL drivers on eBay designed for driving those tubes.

[@nightmareinaction629]

these guy deserve more suscribers he is the best

[@TheBackyardScientist]

Im trying to find something small to charge a few large photoflash capacitors (in series ~700v). Im currently using a small CCFL driver but it only outputs maybe 10ma of current and charging is slow, have you come across anything that would be faster? maybe rewinding the transformers on the commercial inverters?

[@eDoc2020]

I'd look into using a voltage multiplier directly from 120vac. It wouldn't be the safest but as one of your subscribers I'm sure you can handle it.

[@rahmathidayat-rc6ge]

@@eDoc2020 of

[@thesixteenth]

hmm

[@KrazelKraft]

backdoorscienceguy

[@TheEPROM9]

I always play with these when I pull them out of laptops.

[@TheEPROM9]

@@crescendo7357 Only a very small one. But things do become more intresting when you hook a voltage multiplyer to them.

[@TheEPROM9]

@@crescendo7357 No probs, don't go doing naughty things with it. I used mine for powering a night vision tube, the sparks were quite long. But building a tazer is stupidly easy.

[@surplusdriller1]

What driver chip is on that? i got a nearly identical one but no mosfets, but it had a MP1010BEF chip that did al the work.

[@goongoon3111]

as you diagnostic 5v & 12v do you think ..... get same result with 5v?

[@michaelf.9472]

your awesome! I love the way you mix it up! so can I take my inverter out of a Toshiba and put it in Bangalore Acer laptop? ior could I use someone else I don't have the Acer inverter and I really don't want to wait to order it. ? Thanks love your videos!

[@bigclivedotcom]

It depends on the voltage and control signal provided by the main PCB.

[@koushiroizumi0]

Hey Clive! I recently got a big old LCD TV and the CCFL board has six pads: 2*GND, 2*+12V, ADJ and EN. How should i wire this for permanent ON?

[@bigclivedotcom]

If you search my videos for CCFL you'll find one about the drivers and those signals.

[@redsteve7135]

But what if i used for lamp 400 volt ?

[@lowcosttech8026]

so inorder to light it up the backlight of led monitor I need that CCFL driver because I tried to supply directly 12v it didn't turn on.

[@bigclivedotcom]

Backlight LEDs need a suitable driver available from eBay. It boosts the voltage and current regulates it.

[@lowcosttech8026]

@@bigclivedotcom hmmm LCD its broken, I just want to convert into a lamp/light.. i tried also 13v no sign of luck,, brand vertu monitor..

[@SianaGearz]

If the monitor has LED backlight, do NOT use a CCFL driver PCB. You can use CCFL driver if the monitor has a CCFL backlight! Also be aware that this driver PCB only drives one CCFL tube, which is par for the course for many lower-density laptop screens, but not nearly enough for a PC monitor. Typical is 4 CCFL tubes, two on the top edge and two on the bottom. I suppose you could wire two tubes in series, but the assembly would be much less safe and would need special precautions. Oh something to keep in mind, CCFL driver can generate voltages well in excess of 1000V, which is quite lethal. It'll generate as much voltage as it has to, to make up the desired drive current. In either case, the monitor PSU and backlight drive PCB has a 12V point that you can feed externally. However you also then need to supply a little voltage to whatever pin is needed to undim or turn it on. Might take some effort to figure out which. If it's old enough, you're guaranteed to find the schematic to the PCBs in the service manual for some other monitor that uses the same PCB, any given PCB has shown up in monitors by a dozen brands! I can help you with the reverse engineering if need be. So how much of the monitor is broken? Did you break the panel and is the rest working? Other options, PSU/inverter can be dead, or backlight tubes or LEDs can be dead. Service manual and behaviour of the monitor can give some clues.

[@phonotical]

Any chance you could make a video looking at the cathodes for neon tubes

[@sebastiankusyk7764]

can I use an old CCFL backlight inverter to make an ozone generator?

[@bigclivedotcom]

Some can do it. But it's cheap to get ozone modules on eBay.

[@sebastiankusyk7764]

@@bigclivedotcom thanks, I just tried my one, the main problem seems to be that it stops when resistance is to high and has to be restarted. A small neon bulb shines well (not as bright as mercury vapor and doesn't burn out although it's small, because ionised neon doesn't conduct so good). When I disconnected 1 electrode and instead connected some wire around the bulb, it glows too, smells like ozone, but turns off after a couple of seconds.

[@fotoamgamgfoto3695]

hi! if I locate the pins where to connect power, what signal level to connect on the "ON" pin to tourn it on?

[@skotous]

first try ground, if it doesn't respond give it 3.3v or 5v (btw ,not qualified to give you advice, that's just what i would do)

[@TheMatumasa]

Hi, thank you so much for the video, so i'm tryng to light up with the same inverter a ccfl lamp but nothing happen, i'm using 12v 1000 mA with a bridge on the two couple of pin is it ok?

[@TheMatumasa]

could be the cause of my failure the size of the cables? i'm usin a thin cables like awg 24 cable

[@bigclivedotcom]

What length and diameter is the lamp?

[@TheMatumasa]

@@bigclivedotcom Hi, thank you so much for answer, i have two chice, one it's 445mm x 2,4mm and the other it's 350mm x 2,4 mm

[@bigclivedotcom]

It should at least drive the short tube. You may have to play with the enable pins. If it's out of a specific piece of equipment it may require control data

[@TheMatumasa]

@@bigclivedotcom ok, thnks agin for answer, the inventer it's a universal inverter like the one that you are using in the video, it has four pins, maybe i have to try 5v on the switch pin? Do you know how could i wire the "on" pin using two source 12v/5v?

[@dgm778]

manual please!

[@Tech4geeks21st]

I am having 7 pin driver from old laptop how to connect tell me sir

[@bigclivedotcom]

It might be a proprietary connector, but search my videos for CCFL to see videos about various drivers.