Sonsivri

Hello everyone……….
Recently I’ve made a joule thief circuit. It consists of a BD243C transistor, a 22 ohms resistor and a hand wound toroid (4 : 60)…. It can lit up a blue LED (5V forward) with 3V battery n working nicely… then I thought to make a fluorescent tube driver ckt… so I made a transformer of 3 windings and attached it to the joule thief circuit replacing the toroid ( the core was from a broken old CFL lamp circuit). but this ckt isn’t working … I used a 3.7v old battery from a nokia phone(after charging it)... it's strong enough to lit up white LEDs. but doesn't work here..(problem is I have no 6 or 12 v battery n I wanna lit up a little 6w tube with this 3.7v battery)..when I connected the battery , for a moment I saw a dim flash in the tube...n then no response.i got d flash several times at the moment of connecting n disconnecting the battery but tube's not gonna lit up.... the circuit is given below… someone plz help me to find the problem in the ckt…
Thanx…..

i think you don't have a low enough source impedance, and enough power, to drive current into the tube to keep it lit after you've established enough voltage to fire it.  Nothing a Tesla coil won't fix :-)

thanx to solutions... oh sorry  ;D.. forgot to mention 1 thing... i got two old nokia bateries...n once i applied them both in series...multimeter was saying that the open ckt voltage was 7.2v. :D.... but when i connected to ckt n switched on , suddenly voltage dropped to 2.4 volts.. :o
i astonished....... so as you r saying..... high source resistance is the criminal....so y sud I do now?? Is der any other solution to it for the same battery or i must use a new, good 6v battery?? :( n i ddont have any tesla coil. ;D
tahmeed

find an old photo flash unit works on 3V

The battery is not the problem....yet, anyway.  Look up "fluorescent ballast" and you'll see what you need to do to run one off a battery, which I assume is what you are trying to do.

thanx..I checked a no. of electronic ballasts... but they seems very hard to understand... i'm trying to make one d simplest way.. however i've got an idea.. one of my frnds said to me that if i drive the tube with a reasonably high frequency then d amp. needed to sustain d arc in tube will b low..normally joule thiefs give about 20 KHz... so i'm thinking of including a 555 ,100 KHz oscillator...resonate it..n taking voltage across the cap to fire tube.. once it lit.. cap'll be short..let's c what happens. . :)

Might work - that's how the Tesla coil lights one